Abdelhalim Zekry

Abdelhalim Zekry

Ain Shams University

H-index: 28

Africa-Egypt

Abdelhalim Zekry Information

University

Ain Shams University

Position

Professor at Faculty of Engineering

Citations(all)

3292

Citations(since 2020)

2599

Cited By

1322

hIndex(all)

28

hIndex(since 2020)

26

i10Index(all)

82

i10Index(since 2020)

65

Email

University Profile Page

Ain Shams University

Abdelhalim Zekry Skills & Research Interests

Electronics

Electronics for Communications

Photovoltaic

Top articles of Abdelhalim Zekry

Orthogonal beamforming technique for massive MIMO systems

Beamforming represents a pivotal technology in massive multiple-input multiple-output (MIMO) systems, as it facilitates the regulation of transmission and reception operations. Beamforming techniques’ categorization is based either on their hardware architecture or implementation strategy. This paper proposes an orthogonal beamforming technology founded on a specific implementation method that utilizes predetermined orthogonal beams to serve users. The suggested approach incorporates numerous orthogonal beams relying on a substantial number of antennas at the base station. The primary objective of this approach is to enhance the performance of massive MIMO systems by augmenting spectral efficiency and accommodating more users. The proposed beamforming approach is well suited for millimeter frequency bands. The purpose of this paper is to explore the suggested orthogonal beamforming …

Authors

Marwa Abdelfatah,Abdelhalim Zekry,Shaimaa ElSayed

Journal

Annals of Telecommunications

Published Date

2024/2/21

Numerical analysis of carbon-based perovskite tandem solar cells: Pathways towards high efficiency and stability

Multi-junction solar cells exhibit superior power conversion efficiency (PCE) in comparison with their single-junction counterparts. The tunable bandgap, low-cost, elevated short circuit current density (Jsc), and open-circuit voltage (Voc) of perovskite solar cells (PSCs) have led to their widespread adoption as top sub-cells in tandem devices. Stability remains a significant challenge for these cells. To address this issue, carbon perovskite solar cells (CPSCs) have emerged as a potential solution, offering enhanced stability without hole transport layers (HTLs). This study focuses on the simulation of HTL-free CPSCs using an improved electron transport material (ETM) instead of TiO2. The implementation of this enhancement leads to a notable increase in the PCE of the CPSCs, rising from 7.97 % to 14.38 %. Through optimizing the defect concentration and doping density of the perovskite absorber layer, a significant …

Authors

Mostafa M Salah,Ahmed Saeed,Mohamed Mousa,Mohamed Abouelatta,A Zekry,Ahmed Shaker,Fathy Z Amer,Roaa I Mubarak

Published Date

2024/1/1

Acknowledgment to the Reviewers of Electronics in 2022

High-quality academic publishing is built on rigorous peer review. Electronics was able to uphold its high standards for published papers due to the outstanding efforts of our reviewers. Thanks to the efforts of our reviewers in 2022, the median time to first decision was 15 days and the median time to publication was 36 days. Regardless of whether the articles they examined were ultimately published, the editors would like to express their appreciation and thank the following reviewers for the time and dedication that they have shown Electronics:

Authors

ABM Mohaimenur Rahman,Abdelhalim Zekry,AKM Zakir Hossain,Abdelhameed Ibrahim,AA Molnar,Abdelhamid Helali,A Diana Andrushia,Abdelhamied Ashraf,A Díaz-Soriano,Abdelkader Dairi,AF Isakovic,Abdelkader Shaaban,AM Bayomy,Abdellah Chehri,A Quintero,Abdellah Touhafi,A Rajesh,Abdellatif Elmouatamid,AS Shinde,Abdelrahman Eldosouky,AH Alamoodi,Abdessamad Didi,AP James,Abdu Gumaei,ASB Sombra,Abdul Aabid,Aaqif Afzaal,Abdul Majeed,Aarón Ángel Salas-Sánchez,Abdul Quadir Md,Aaron Jaufenthaler,Abdul Waheed,Aashish Kumar Bohre,Abdul Wahid,Aashish Mathur,Abdulateef Balogun,Abas Sabouni,Abdulatif Alabdulatif,Abbas Abbaszadeh Shahri,Abdulaziz Aborujilah,Abbas Haddadi,Abdulghafor A Abdulhameed,Abbas Javed,Abdulkadir Seker,Abbas Nasri,Abdulkafi Saeed,Abbas Orand,Abdullah Al-Aboosi,Abbas Shah Syed,Abdullah Alghamdi,Abbass Nasser,Abdullah Al-Hadi Azremi,Abbott Po Shun Chen,Abdullah Ayub,Abdallah A Smadi,Abdullah Eial Awwad,Abd-Allah Hyder,Abdullah Lakhan,Abdel Fattah Sheta,Abdullahi Abubakar Mas’ud,Abdel-Baset MA Ibrahim,Abdulsamed Tabak,Abdelbasset Krama,Abdulsattar Abdullah Hamad,Abdelhak Merizig,Abdul-Sattar Kaddour

Published Date

2023

Investigation of high-efficiency and stable carbon-perovskite/silicon and carbon-perovskite/CIGS-GeTe tandem solar cells

The primary purpose of recent research on solar cells is to achieve a higher power conversion efficiency with stable characteristics. To push the developments of photovoltaic (PV) technology, tandem solar cells are being intensively researched, as they have higher power conversion efficiency (PCE) than single-junction cells. Perovskite solar cells (PSCs) are recently used as a top cell of tandem solar cells thanks to their tunable energy gap, high short circuit current, and low cost of fabrication. One of the main challenges in PSCs cells is the stability issue. Carbon perovskite solar cells (CPSCs) without a hole transport material (HTM) presented a promising solution for PSCs’ stability. The two-terminal monolithic tandem solar cells demonstrate the commercial tandem cells market. Consequently, all the proposed tandem solar cells in this paper are equivalent to two-terminal monolithic tandem devices. In this work, two two-terminal tandem solar cells are proposed and investigated using the SCAPS-1D device simulator. Carbon perovskite solar cell (CPSC) without hole transport material (HTM) is used as the top cell with a new proposed gradient doping in the perovskite layer. This proposal has led to a substantial enhancement of the stability issue known to be present in carbon perovskite cells. Moreover, a higher PCE, exceeding 22%, has been attained for the proposed CPSC. Two bottom cells are examined, Si and CIGS-GeTe solar cells. The suggested CPSC/Si and CPSC/CIGS-GeTe tandem solar cells have the advantage of having just two junctions, which reduces the complexity and cost of solar cells. The performance parameters are found to …

Authors

Ahmed Saeed,Mostafa M Salah,Abdelhalim Zekry,Mohamed Mousa,Ahmed Shaker,Mohamed Abouelatta,Fathy Z Amer,Roaa I Mubarak,Dalia S Louis

Journal

Energies

Published Date

2023/2/8

A comprehensive review of tandem solar cells integrated on silicon substrate: Iii/v vs perovskite

High-efficiency solar cells with low manufacturing costs have been recently accomplished utilizing different technologies. III-V-based tandem solar cells have exhibited performance enhancement with a recent efficiency of greater than 39% under AM1.5G and 47% under concentration. Integration of such III-V materials on a relatively cheap Silicon (Si) substrate is a potential pathway to fabricate high-efficient low-cost tandem solar cells. Besides, perovskite solar cells, as third-generation thin film photovoltaics (PV), have been meteorically developed at a reasonable cost. At present, there are still questions for cost reduction of perovskite materials and solar cell modules because of their limited commercialization. In this review, stacking Si solar cells with III-V material to form Si-based III-V tandem solar cells is presented with different integration technological routes. Also, perovskite/Si tandem solar cells have been …

Authors

Omar M Saif,Abdel Halim Zekry,Mohamed Abouelatta,Ahmed Shaker

Published Date

2023/10

User Selection Methods for Overcoming Growing Number of Served Users in Massive MIMO Systems

Massive MIMO is dominant in the current wireless communication systems. Massive MIMO system uses a massive number of antennas to serve multi-users simultaneously. The growth of served users in the system will increase the interference between them and affect the system’s performance. To maintain the qualified service for the growing number of users, user selection techniques can be used to separate users into groups to be served well. This paper proposes three user selection methods named Mean Step User Selection (MSUS), Second Null User Selection (SNUS), and Interference Threshold User Selection (ITUS) methods. These three user selection methods aim to serve users with the best possible performance. The performance of these proposed user selection methods will be evaluated and compared with the performance of the system without selection and with the system using other user …

Authors

Marwa Abdelfatah,Abdelhalim Zekry,Shaimaa ElSayed

Journal

IEEE Access

Published Date

2023/6/12

Enhanced Multiple Speakers’ Separation and Identification for VOIP Applications Using Deep Learning

Institutions have been adopting work/study-from-home programs since the pandemic began. They primarily utilise Voice over Internet Protocol (VoIP) software to perform online meetings. This research introduces a new method to enhance VoIP calls experience using deep learning. In this paper, integration between two existing techniques, Speaker Separation and Speaker Identification (SSI), is performed using deep learning methods with effective results as introduced by state-of-the-art research. This integration is applied to VoIP system application. The voice signal is introduced to the speaker separation and identification system to be separated; then, the “main speaker voice” is identified and verified rather than any other human or non-human voices around the main speaker. Then, only this main speaker voice is sent over IP to continue the call process. Currently, the online call system depends on noise cancellation and call quality enhancement. However, this does not address multiple human voices over the call. Filters used in the call process only remove the noise and the interference (de-noising speech) from the speech signal. The presented system is tested with up to four mixed human voices. This system separates only the main speaker voice and processes it prior to the transmission over VoIP call. This paper illustrates the algorithm technologies integration using DNN, and voice signal processing advantages and challenges, in addition to the importance of computing power for real-time applications.

Authors

Amira A Mohamed,Amira Eltokhy,Abdelhalim A Zekry

Journal

Applied Sciences

Published Date

2023/3/28

A New Refined-TLBO Aided Bi-Generative Adversarial Network for Finger Vein Recognition

Finger vein recognition is a biometric authentication scheme for analyzing human finger vein patterns. Over the past few decades, Convolutional Neural Networks (CNN) have been widely used for finger vein recognition. However, the conventional issues of CNN are remaining unsolved which are translation invariance and the lack of considerations of position and orientation, thus unable to obtain a large recognition rate. In addition, pre-processing for all kind of finger vein images lead to extra overhead and increases the time for finger vein recognition. In this paper, we proposed a Bi-Generative Adversarial Network (Bi-GAN) with Teaching Learning Based Optimization (TLBO) for finger vein recognition. GAN is an architecture that can use CNNs and are really powerful in learning the underlying data distribution. Further, GAN has been applied previously for this application, but still, it has some serious issues such as hyper-parameters selection, and insufficiency for large feature extraction. Our proposed Bi-GAN with TLBO approach is involved four processes:(1) Image Quality Assessment (IQA),(2) Preprocessing,(3) Feature extraction,(4) Feature matching. We extract texture and soft biometric trait features by Bi-GAN and the parameters are optimized using the TLBO algorithm. In feature matching, we used Canberra Coefficient (CE). Experiments are conducted on the SDUMLA public database that exhibits the efficiency of the proposed Bi-GAN and TLBO in finger vein recognition. The results proved that the proposed approach is superior as analyzed to the CNN, GAN, and Bi-GAN approaches and gives the improvement in the accuracy of …

Authors

Hossam L Zayed,Heba M Abdel Hamid,Yasser M Kamal,Abdel Halim A Zekry

Journal

Journal of Advances in Information Technology

Published Date

2023

Deep learning channel estimation for OFDM 5G systems with different channel models

At cellular wireless communication systems, channel estimation (CE) is one of the key techniques that are used in Orthogonal Frequency Division Multiplexing modulation (OFDM). The most common methods are Decision‐Directed Channel Estimation, Pilot-Assisted Channel Estimation (PACE) and blind channel estimation. Among them, PACE is commonly used and has a steadier performance. Applying deep learning (DL) methods in CE is getting increasing interest of researchers during the past 3 years. The main objective of this paper is to assess the efficiency of DL-based CE compared to the conventional PACE techniques, such as least-square (LS) and minimum mean-square error (MMSE) estimators. A simulation environment to evaluate OFDM performance at different channel models has been used. A DL process that estimates the channel from training data is also employed to get the estimated impulse …

Authors

Aliaa Said Mousa Mohammed,Abdelkarim Ibrahim Abdelkarim Taman,Ayman M Hassan,Abdelhalim Zekry

Journal

Wireless Personal Communications

Published Date

2023/2

Proposal for Repairable Silicon Solar Panels: Proof of Concept

The long-term performance of traditional solar panels can be affected by various climate conditions, resulting in issues such as decreased power output, interconnector failure, and cell fracture. Unfortunately, traditional modules are not repairable, and often the entire unit must be replaced, even if the failure is due only to a single component. In this work, conventional encapsulation methods are investigated, and a novel solar panel design approach is introduced. This innovative approach enables easy and direct access to individual components, thereby enabling the convenient carrying out of repairs, upgrades, and modifications. The proposed module configuration is composed of a double-layer structure. The initial layer functions as a protective glass cover while the second layer is made up of solar cells that are attached to a printed circuit board (PCB) that can endure high temperatures. These two layers are combined within an aluminum frame that can be opened for accessibility. To test the effectiveness of this new encapsulation technique, an experimental study was conducted. It was revealed through this experimental study that the dark and illuminated current–voltage characteristics are not affected when applying the new encapsulation technique. Furthermore, a theoretical thermal analysis was conducted in order to compare the performance of the proposed module with that of a conventional module. According to the thermal analysis, the proposed encapsulation method should result in slightly higher thermal stress on the solar cells compared with conventional encapsulation. Nonetheless, the proposed methodology offers advantages in …

Authors

Ehab El-Fayome,Abdel Halim Zekry,Mohamed A Abdelhamed,Ahmed EL-Shazly,Mohamed Abouelatta,Ahmed Shaker,Ahmed Saeed

Journal

Energies

Published Date

2023/9/8

Analytical and Numerical Investigation of Nanowire Transistor X-ray Detector

Recently, nanowire detectors have been attracting increasing interest thanks to their advantages of high resolution and gain. The potential of using nanowire detectors is investigated in this work by developing a physically based model for Indium Phosphide (InP) phototransistor as well as by performing TCAD simulations. The model is based on solving the basic semiconductor equations for bipolar transistors and considering the effects of charge distribution on the bulk and on the surface. The developed model also takes into consideration the impact of surface traps, which are induced by photogenerated carriers situated at the surface of the nanowire. Further, photogating phenomena and photodoping are also included. Moreover, displacement damage (DD) is also investigated; an issue arises when the detector is exposed to repeated doses. The presented analytical model can predict the current produced from the incident X-ray beam at various energies. The calculation of the gain of the presented nanowire carefully considers the different governing effects at several values of energies as well as biasing voltage and doping. The proposed model is built in MATLAB, and the validity check of the model results is achieved using SILVACO TCAD device simulation. Comparisons between the proposed model results and SILVACO TCAD device simulation are provided and show good agreement.

Authors

Abdelhady Ellakany,Abdelhalim Zekry,Mohamed Abouelatta,Ahmed Shaker,Gihan T Sayah,Mohamed M El-Banna

Journal

Materials

Published Date

2023/3/27

Performance Evaluation of X-Ray Nanowire Photoconductor Detector

This article describes the use of the SILVACO TCAD device simulator to inspect the electrical performance of a proposed nanowire (NW) X-ray detector. The objective of this work is to obtain a better physical understanding of the behavior of the detector, specifically as a photoconductor type, under different conditions such as flux density, biasing voltage, NW diameter, active region length and temperature. When the length is changed from 1.8 to 1.0 , the output conductance is changed from 4 to 14 . The simulation results predict the current produced by incident X-ray beams and the gain, while taking into account the relationship between the diameter and energy gap of InP nanowires. The simulation results show that the overall gain is in the range from 10 3 to 10 5 when the flux changes from to Ph/s. The study also models a single semiconductor nanowire and …

Authors

A Ellakany,A Zekry,M Abouelatta,A Shaker,M ElBanna

Published Date

2023/5/30

A comprehensive survey on finger vein biometric

In the present society with quick outgrowth in electronic field info innovation, the security issue became important demand. Because of this truth, biometric verification has earned populist as it grants reliable and high-security methodology for personalized authentication. Finger vein biometry is a recognition strategy utilized to investigate finger vein models of people for proper verification. Finger vein biometry is one of the arising technics of different types owing to its aliveness baring, its qualities of low faking risk, and a part of stability throughout a significant time. A review of advances in biometrics of finger veins is presented in the paper. It concentrates on the following sides: the overall finger vein presentation, its stages comprising image acquisition, preprocessing, extraction of features, as well as matching, the current research work review, and the common datasets. At last, the applications, the challenges, and future directions are worked out. The paper is trying to collect all studies on finger vein biometry to be one comprehensive which helps the researcher to get easily started with their investigations in the finger vein biometry where it also demonstrates the advantages and disadvantages of different biometric traits to choose from them, it focuses on explaining each part in finger vein biometry, it highlights the current challenges, provides a proposed solution and shows different technologies to encourage the scientific researchers to complete working on it.

Authors

Hossam L Zayed,Heba M Abdel Hamid,Yasser M Kamal,Abdel Halim A Zekry

Published Date

2023

Underlay Spectrum Sharing with L-Band Distance Measuring Equipment for Aeronautical Communications

The monitoring of an aircraft during its flight phases is crucial to the performance of air-to-ground (A/G) communication designed for air traffic management (ATM) purposes. Due to the everyday increasing air traffic, A/G communications have been transferred from the congested very high frequency band to occupy the guard bands between adjacent distance measurement equipment (DME) channels within the L-Band. However, the inlayed channels, called L-Band digital aeronautical communications (LDACS) channels, experience severe interference with the coexisting DME channels. The previous work depends on both DME interference detection and mitigation techniques. In this paper, a DME interference mitigation technique is proposed to improve the performance of the LDACS type I (LDACSI) system without requiring the detection process. The proposed technique depends on the underlay spectrum sharing …

Authors

Emad Abd-Elaty,Abdelhalim Zekry,Salah El-Agooz,Anwar M Helaly

Journal

Wireless Personal Communications

Published Date

2023/2

Design and Optimization of a Self-Protected Thin Film c-Si Solar Cell against Reverse Bias

Current mismatch due to solar cell failure or partial shading of solar panels may cause a reverse biasing of solar cells inside a photovoltaic (PV) module. The reverse-biased cells consume power instead of generating it, resulting in hot spots. To protect the solar cell against the reverse current, we introduce a novel design of a self-protected thin-film crystalline silicon (c-Si) solar cell using TCAD simulation. The proposed device achieves two distinct functions where it acts as a regular solar cell at forward bias while it performs as a backward diode upon reverse biasing. The ON-state voltage (VON) of the backward equivalent diode is found to be 0.062 V, which is lower than the value for the Schottky diode usually used as a protective element in a string of solar cells. Furthermore, enhancement techniques to improve the electrical and optical characteristics of the self-protected device are investigated. The proposed solar cell is enhanced by optimizing different design parameters, such as the doping concentration and the layers’ thicknesses. The enhanced cell structure shows an improvement in the short-circuit current density (JSC) and the open-circuit voltage (VOC), and thus an increased power conversion efficiency (PCE) while the VON is increased due to an increase of the JSC. Moreover, the simulation results depict that, by the introduction of an antireflection coating (ARC) layer, the external quantum efficiency (EQE) is enhanced and the PCE is boosted to 22.43%. Although the inclusion of ARC results in increasing VON, it is still lower than the value of VON for the Schottky diode encountered in current protection technology.

Authors

Omar M Saif,Abdelhalim Zekry,Ahmed Shaker,Mohammed Abouelatta,Tarek I Alanazi,Ahmed Saeed

Journal

Materials

Published Date

2023/3/21

A Proposed Deep-Learning-Based Framework for Medical Image Communication, Storage and Diagnosis

Medical images rather than any other types of images need high storage space. The lack of storage facilities, especially in developing countries, encourages researchers to find solutions for this problem. Compression of medical images is a priority, although it leads to some loss in the stored images. This paper introduces a framework for medical image storage and retrieval for the purpose of diagnosis. This framework adopts decimation as a tool for image compression, while interpolation is used as a tool for further image reconstruction. The quality of the reconstructed images is evaluated with a scale-invariant feature transform (SIFT)-based technique. Another task involved in this paper is the automatic diagnosis from the reconstructed images based on deep learning. Different types of interpolation algorithms are investigated and compared in this framework for the process of medical image reconstruction.

Authors

Mostafa Ebied,FA Elmisery,Noha A El-Hag,Ahmed Sedik,Walid El-Shafai,Ghada M El-Banby,Eman Soltan,Nayel Al-Zubi,Ayman Brisha,Abdelhalim Zekry,Ashraf AM Khalaf,Adel S El-Fishawy,El-Sayed M El-Rabaie,Waleed Al-Nuaimy,Fathi E Abd El-Samie

Journal

Wireless Personal Communications

Published Date

2023/8

Numerical Simulation and Design of All-Thin-Film Homojunction Perovskite/c-Si Tandem Solar Cells

Double-junction solar devices featuring wide-bandgap and narrow-bandgap sub-cells are capable of boosting performance and efficiency compared to single-junction photovoltaic (PV) technologies. To achieve the best performance of a double-junction device, careful selection and optimization of each sub-cell is crucial. This work presents the investigation of an all-thin-film two-terminal (2T) monolithic homojunction perovskite (PVK)/c-Si tandem cell using Silvaco TCAD simulation. The front sub-cell utilizes homojunction PVK that has a bandgap of 1.72 eV, whereas the rear sub-cell uses thin c-Si with a bandgap of 1.12 eV. Both cells are connected via a p++/n++ silicon tunnel diode. Experimental calibration of the heterojunction PVK and c-Si cells yields power conversion efficiencies (PCE) of 18.106% and 17.416%, respectively. When integrated into an initial PVK/c-Si tandem, the resulting cell achieves a PCE of …

Authors

Omar M Saif,Ahmed Shaker,Mohamed Abouelatta,Abdelhalim Zekry,Yasmine Elogail

Journal

Silicon

Published Date

2023/12/13

End Of Life Management Of Solar Panels

The typical solar module has numerous drawbacks when used for extended periods of time in environmental conditions. Examples include cracked cells, interconnection failure, and decreasing output power. Also, it cannot be repaired; once a fault occurred in one cell, the module must be replaced. The proliferation of unused solar panels has become an issue due to the vast increase in the use of solar energy resources. While the current focus of solar panel research is to increase production energy efficiency, solar panel repairability and recycling of end of life (EOL) panels is rarely considered. The management of the EOL panels can efficiently save natural resources and save production costs. This study explores conventional encapsulation methods and introduces a novel approach to solar panel design that allows for easy access to individual components, facilitating repairs, upgrades, and modifications. The …

Authors

E El-fayome,MA Abdelhamed,A El-Shazly,M Abouelatta,A Zekry

Published Date

2023/5/30

PV Solar Yield Applicable Simulator Based on Free Irradiance Data Source: Applied Comprehensive Tool for Solar Engineers. Energy Engineering

Accurate PV system simulators are implemented with expensive software platforms using paid irradiance data. The main purpose of this paper is to develop and validate a PV system simulator, beginning with a solar cell parameter extraction model, then test and validate long-term Irradiance data using free online source (Typical Meteorological Year TMY in (PVGIS) European website), and finally building full solar generator simulator to run in working real conditions. Comparing results with Accurate Paid PV simulators (which use the Muneer model) showed good accuracy of the proposed simulator. Work flow starts with the Irradiance model’s data processing, then solar cell 5 parameters model data processing (to extract cell parameters), and finally full system simulator. MATLAB coding programs in real working conditions are used for simulation. Results of solar cell parameter extraction show 99.6% to 99.99% matching with data sheet and cell performance under standard test conditions. System model simulation output shows 8% less yearly generated energy compared to the PVGIS 2022 long-term simulation (hourly basis (one-year time)). This is due to incident energy variations (between the years 2016 and 2022) of 4.02%. The novelty of the algorithm is the methodology, as it tests irradiance data on an hourly basis and validates results for a whole continuous year. Also, the 5-parameter solar cell model is used to be validated in long term analysis, not only STC conditions and could be applied on any PV solar cell. The algorithm and block diagram used are scalable, modular, and interchangeable with similar models to be tested. This …

Authors

AMZAAHAY Ragab,Abdelhalim Abdelnaby Zekry,Ashraf Yahia Hassan

Journal

Energy Engineering.

Published Date

2023

Successive approximation register analog-to-digital converter (SAR ADC) for biomedical applications

This study presents a survey of the most promising reported SAR ADC designs for biomedical applications, stressing advantages, disadvantages, and limitations, and concludes with a quantitative comparison. Recent progress in the development of a single SAR ADC architecture is reviewed. In wearable and biosensor systems, a very small amount of total power must be devoured by portable batteries or energy-harvesting circuits in order to function correctly. During the past decade, implementation of the high energy efficiency of SAR ADC has become the most necessary. So, several different implementation schemes for the main components of the SAR ADC have been proposed. In this review study, the various circuit architectures have been explained, beginning with the sample and hold (S/H) switching circuits, the dynamic comparator, the internal digital-to-analog converter (DAC), and the SAR control logic. In order to achieve low power consumption, numerous different configurations of dynamic comparator circuits are revealed. At the end of this overview, the evolutions of DAC architecture in distinct biomedical applications today can make a tradeoff between resolution, speed, and linearity, which represent the challenges of a single SAR ADC. For high resolution, the dual split capacitive DAC (CDAC) array technique and hybrid capacitor technique can be used. Also, for ultralow power consumption, various voltage switching schemes are achieved to reduce the number of switches. These schemes can save switching energy and reduce capacitor array area with high linearity. Additionally, to increase the speed of the conversion process, a …

Authors

Kawther I Arafa,Dina M Ellaithy,Abdelhalim Zekry,Mohamed Abouelatta,Heba Shawkey

Published Date

2023/1/4

Efficient hybrid algorithm for human action recognition

Recently, researchers have sought to find the ideal way to recognize human actions through video using artificial intelligence due to the multiplicity of applications that rely on it in many fields. In general, the methods have been divided into traditional methods and deep learning methods, which have provided a qualitative leap in the field of computer vision. Convolutional neural network CNN and recurrent neural network RNN are the most popular algorithms used with images and video. The researchers combined the two algorithms to search for the best results in a lot of research. In an attempt to obtain improved results in motion recognition through video, we present in this paper a combined algorithm, which is divided into two main parts, CNN and RNN. In the first part there is a preprocessing stage to make the video frame suitable for the input of both CNN networks which consist of a fusion of Inception-ResNet-V2 and GoogleNet to obtain activations, with the previously trained wights in Inception-ResNet-V2 and GoogleNet and then passed to a deep Gated Recurrent Units (GRU) connected to a fully connected SoftMax layer to recognize and distinguish the human action in the video. The results show that the proposed algorithm gives better accuracy of 97.97% with the UCF101 dataset and 73.12% in the hdmb51 data set compared to those present in the related literature.

Authors

Mostafa A Abdelrazik,Abdelhaliem Zekry,Wael A Mohamed

Journal

Journal of Image and Graphics

Published Date

2023/3

Design and Implementation of SDR Platform for Radar Applications

Radar systems are an interesting application of SDR due to SDR’s low cost and high configurability compared to traditional radar systems. During this research, a complete SDR system was designed and implemented targeting radar applications. The component used in this design were chosen carefully to afford a wide operating range, high speed, low power dissipation, small size, low cost, configurability, low noise, and good performance. The implemented SDR can transmit and receive signals up to 6.8 GHz with 100 MHz instantaneous bandwidth. The system’s small size and good performance suit portable UAVs, SAR, and imaging radars. This research used the implemented SDR as an FMCW radar system capable of detecting motion behind numerous barriers by employing an FPGA as a real-time signal processor. The proposed UWB FMCW radar can penetrate walls and provide exact range resolution to …

Authors

Kamal Hussein,Ahmed SI Amar,Abdelhalim Zekry,Mohamed Abouelatta,Ahmed Khairy Mahmoud,Mohamed Mabrouk

Published Date

2023/7/18

Comprehensive Review on Thin Film Homojunction Solar Cells: Technologies, Progress and Challenges

With the aim of achieving high efficiency, cost-effectiveness, and reliability of solar cells, several technologies have been studied. Recently, emerging materials have appeared to replace Si-based cells, seeking economic fabrication of solar cells. Thin-film solar cells (TFSCs) are considered strong candidates for this mission, specifically perovskite-based solar cells, reporting competitive power convergence efficiencies reaching up to 25.7%. Substantial efforts have been invested in experimental and research work to surpass the Si-based cells performance. Simulation analysis is a major tool in achieving this target by detecting design problems and providing possible solutions. Usually, a TFSC adopts p-i-n heterojunction architecture by employing carrier transport materials along with the absorber material in order to extract the photogenerated electrons and holes by realizing a built-in electric field. Eventually, this dependency of conventional heterojunction TFSCs on carrier transport layers results in cost-ineffective cells and increases the possibility of device instability and interface problems. Thus, the design of p-n homojunction TFSCs is highly desirable as an essential direction of structural innovation to realize efficient solar cell operation. In this review, a summary of the fundamentals of TFSC materials, recent design and technology progress, and methodologies for improving the device performance using experimental research studies will be discussed. Further, simulation analysis will be provided by demonstrating the latest research work outcomes, highlighting the major achievements and the most common challenges facing thin film …

Authors

Omar M Saif,Yasmine Elogail,Tarek M Abdolkader,Ahmed Shaker,Abdelhalim Zekry,Mohamed Abouelatta,Marwa S Salem,Mostafa Fedawy

Published Date

2023/5/30

Innovative Solar Photovoltaic Solutions for Water-Efficient Irrigation: A Comprehensive Algorithmic Approach

This study presents a pioneering integrated comprehensive model for photovoltaic solar pumping irrigation systems, addressing critical challenges prevalent in Egypt and other developing countries. These challenges primarily revolve around the scarcity of fossil fuels and the imperative need for optimizing renewable energy usage in agriculture, as well as rectifying irrigation inefficiencies in both established and emerging agricultural areas, where flood irrigation remains a predominant but resource-intensive practice. Our proposed model synthesizes principles from agricultural science, irrigation science, and photovoltaic solar engineering. To demonstrate its efficacy, we conducted a comprehensive case study in Egypt. The results underscore the transformative potential of our approach, revealing a substantial reduction in water consumption, approximately 30% lower than that of conventional flood irrigation …

Authors

Ahmed Mohamed Ragab,Abdelhalim Abdelnaby Zekry,Ashraf Yahia Hassan

Published Date

2023/11/15

Acknowledgment to the Reviewers of Energies in 2022

High-quality academic publishing is built on rigorous peer review. Energies was able to uphold its high standards for published papers due to the outstanding efforts of our reviewers. Thanks to the efforts of our reviewers in 2022, the median time to first decision was 16 days and the median time to publication was 38 days. Regardless of whether the articles they examined were ultimately published, the editors would like to express their appreciation and thank the following reviewers for the time and dedication that they have shown Energies:

Authors

A Amarender Reddy,Abdelkader Dairi,A Nabavi-Pelesaraei,Abdellah Chehri,AM Hamed,Abdellah El-Hadj Abdellah,A Ouadah,Abdelmonaem Jornaz,A Raja Annamalai,Abdelrahman H Hassan,A Rajput,Abdelrahman Zkria,A Toshimitsu Yokobori,Abdennour Seibi,Aaditya Khanal,Abderrahim Bouaid,Aamir Khan,Abderrahime Sekkat,Aamod Desai,Abderrahmane Aissa,Aapo Huovila,Abderrazak Boutramine,Aaron H Persad,Abdessamad Didi,Aashish Kumar Bohre,Abdo Abdullah Ahmed Gassar,Abasifreke U Ebong,Abdul Aabid,Abbas Abbaszadeh Shahri,Abdul Aziz Abdul Raman,Abbas Ali Abid,Abdul Baseer Mohammed,Abbas Ali Chandio,Abdul Gani Abdul Jameel,Abbas Haddadi,Abdul Hafaz Ngah,Abbas Javed,Abdul Hasib Chowdhury,Abbas Nasri,Abdul Latif,Abdalla Abou Jaoude,Abdul Majeed Shar,Abdallah Samad,Abdul Mohamed,Abdel Razzaq Al-Tawaha,Abdul Muntaqim Naji,Abdelaal Ahmed,Abdul Rahim Ridzuan,Abdelazim Ahmed,Abdul Raouf Tajik,Abdelaziz Gamil,Abdul Rauf,Abdelaziz M Aboraia,Abdul Salam Shah,Abdelbasset Krama,Abdulaziz Alanazi,Abdelfatah Ali,Abdulaziz Alsulami,Abdelgawad Elsadany,Abdulaziz Ellafi,Abdelhakim Elmouwahidi,Abdulaziz M Abdulaziz,Abdelhalim Ebaid,Abdulfatah A Yusuf,Abdelhalim Mohamed,Abdulhameed Babatunde,Abdelhalim Zekry,Abdulkafi Saeed

Published Date

2023

Boosting the Electrostatic MEMS Converter Output Power by Applying Three Effective Performance-Enhancing Techniques

This current study aims to enhance the electrostatic MEMS converter performance mainly by boosting its output power. Three different techniques are applied to accomplish such performance enhancement. Firstly, the power is boosted by scaling up the technology of the converter CMOS accompanied circuit, the power conditioning, and power controlling circuits, from 0.35 µm to 0.6 µm CMOS technology. As the converter area is in the range of mm2, there are no restrictions concerning the scaling up of the accompanied converter CMOS circuits. As a result, the maximum voltage of the system for harvesting energy, Vmax, which is the most effective system constraint that greatly affects the converter’s output power, increases from 8 V to 30 V. The output power of the designed and simulated converter based on the 0.6 µm technology increases from 2.1 mW to 4.5 mW. Secondly, the converter power increases by optimizing its technological parameters, the converter thickness and the converter finger width and length. Such optimization causes the converter output power to increase from 4.5 mW to 11.2 mW. Finally, the converter structure is optimized to maximize its finger length by using its wasted shuttle mass area which does not contribute to its capacitances and output power. The proposed structure increases the converter output power from 11.2 mW to 14.29 mW. Thus, the three applied performance enhancement techniques boosted the converter output power by 12.19 mW, which is a considerable enhancement in the converter performance. All simulations are carried out using COMSOL Multiphysics 5.4.

Authors

Mona S Salem,Abdelhalim Zekry,Mohamed Abouelatta,Ahmed Shaker,Marwa S Salem,Christian Gontrand,Ahmed Saeed

Journal

Micromachines

Published Date

2023/2/19

Optimizing SIFT algorithm parameters for better matching UAV and satellite images

Image registration has been increasingly employed in various applications such as target identification, 3D mapping, and motion tracking. The main idea of Image registration is aligning two or more images of the same scene captured from different viewpoints, at different times. Scale-invariant feature transform, SIFT, is considered one of the most robust algorithms used in image registration for extracting and matching features under different conditions. Using SIFT algorithm default parameters in Matching UAV and satellite Images provides unreliable results due to the nature of aerial images because the dynamic range is quite low. The number of extracted features depends on the image content and the selected parameters. In this paper we tuned SIFT parameters to get the best performance with aerial images, to increase the number of features (SM) and the correct match rate (CMR) which increases the efficiency …

Authors

KA Elorabi,A Zekry,WA Mohamed

Journal

Journal of Physics: Conference Series

Published Date

2023/11/1

A mm-Wave Radio Frequency Power Amplifier based on Transformers Coupling and 2 nd Harmonic Termination Network using 130 nm CMOS Technology for 5G Applications

An efficient and linear power amplifier (PA) for millimeter wave applications using a 130nm CMOS process is presented in this paper. The proposed PA uses transformer coupling for output, inter-stage, and input matching and also utilizes inter-stage inductors to boost RF achievement. The Ansoft high-frequency structure simulator (HFSS) is used to analyze and design the coupling transformers and inter-stage matching inductors to achieve a high coupling coefficient and quality factor over the frequency range of 19 to 29 GHz. The 2 harmonic termination networks are connected at each stage of the proposed power amplifier to enhance the gain and efficiency. The suggested radio frequency power amplifier consists of three stages, the input stage operates in class-B operation to increase the efficiency without an influence on the DC power consumption, while the driver and power stages work in class-AB to improve the RF output power. Also, the power stage is a parallel combination of class-B and class-AB to improve the one-dB compression point and enhance the linearity. The proposed RF power amplifier operates in the frequency range from 19 to 29 GHz. The suggested PA achieves a saturated output power of 15.1 dBm, a maximum power added efficiency (PAE) of 19.35%, and a peak power gain of 22.72 dB. Moreover, the peak output 1-dB compression point for the proposed power amplifier is 13.1 dBm and consumes a DC power of 98.09 mW. Lastly, the die and overall areas of the suggested power amplifier are 0.4 mm and 0.67 mm, respectively.

Authors

Mina Kamal,Marwa Mansour,Sherif Hekal,Abdelhalim Zekry

Published Date

2023/7/6

Efficient Deep Learning Algorithm for Egyptian Sign Language Recognition

Although most people can communicate effectively through speech, some have difficulties doing so due to physical or mental impairments. Communication is a significant obstacle for individuals with these disabilities. Methods of deep learning can aid in the elimination of communication barriers. This article proposes a model based on deep learning for detecting and recognizing words from gestures. Deep learning models such as Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) are used to recognize signs from Egyptian Sign Language (ESL) video frames. There are many activation functions, and every type has advantages and disadvantages. All these activation functions were applied to our dataset for ESL. To overcome the main disadvantage of the Relu activation function, we proposed a gesture recognition method for ESL using Mediapipe and modified GRU with a new activation function …

Authors

Mostafa A Abdelrazik,Abdelhaliem Zekry,Wael A Mohamed

Published Date

2023/5/24

An accurate partial shading detection and global maximum power point tracking technique based on image processing

This paper aims to detect the existence of partial shading conditions on the PV array and to estimate the vicinity of the global maximum power point for shaded PV modules based solely on the captured image of the PV modules. Detecting the existence of partial shading is based on comparing the average image pixel intensity for each PV module to find any mismatch in the incident irradiance. Estimating the incident irradiance level of each PV module is based on the camera response function with the help of a reference module. Furthermore, after estimating the irradiance intensity on the modules, we used the captured image for each PV module to detect the shaded area percentage. Detect the presence of partial shading conditions and estimating the position of the Global Maximum Power Point under partial shading was achieved with simple and cheap procedure yet effective at various shading patterns regardless of the environmental circumstances.

Authors

Ahmed K Ryad,Ahmed M Atallah,Abdelhalim Zekry

Journal

Engineering Review: Međunarodni časopis namijenjen publiciranju originalnih istraživanja s aspekta analize konstrukcija, materijala i novih tehnologija u području strojarstva, brodogradnje, temeljnih tehničkih znanosti, elektrotehnike, računarstva i građe

Published Date

2022/7/14

Performance Improvement of npn Solar Cell Microstructure by TCAD Simulation: Role of Emitter Contact and ARC

In the current study, the performance of the npn solar cell (SC) microstructure is improved by inspecting some modifications to provide possible paths for fabrication techniques of the structure. The npn microstructure is simulated by applying a process simulator by starting with a heavily doped p-type substrate which could be based on low-cost Si wafers. After etching deep notches through the substrate and forming the emitter by n-type diffusion, an aluminum layer is deposited to form the emitter electrode with about 0.1 µm thickness; thereby, the notches are partially filled. This nearly-open-notches microstructure, using thin metal instead of filling the notch completely with Al, gives an efficiency of 15.3%, which is higher than the conventional structure by 0.8%. Moreover, as antireflection coating (ARC) techniques play a crucial role in decreasing the front surface reflectivity, we apply different ARC schemes to inspect their influence on the optical performance. The influence of utilizing single layer (ZnO), double (Si3N4/ZnO), and triple (SiO2/Si3N/ZnO) ARC systems is investigated, and the simulation results are compared. The improvement in the structure performance because of the inclusion of ARC is evaluated by the relative change in the efficiency (Δη). In the single, double, and triple ARC, Δη is found to be 12.5%, 15.4%, and 17%, respectively. All simulations are performed by using a full TCAD process and device simulators under AM1.5 illumination.

Authors

Marwa S Salem,Abdelhalim Zekry,Ahmed Shaker,Mohamed Abouelatta,Tariq S Almurayziq,Mohammad T Alshammari,Mohamed M El-Banna

Journal

Energies

Published Date

2022/9/29

Home Energy Management System Based on Priority of devices

The rising number of home devices, as well as the differences in technology between them (smart and traditional), are the causes of the difficulty in balancing the use of energy in the home. Furthermore, increased demand for energy often leads to pressure on electricity networks and utilities, which leads to interruptions or disruptions of services caused by peak load. All these factors contribute to the adoption of energy management systems to control and reduce usage and automatically monitor the usage of home devices. When consumption is controlled, it is beneficial to customers and electricity companies when demand is reduced at peak times.This research will present a prototype for an energy management system to control and monitor the usage of devices in the home, and automatic control utilizing MATLAB simulation and implementation employing a Microcontroller to assess Demand Response.The suggested algorithm would manage consumption to reach the lowest usage possible to decrease the monthly bill, reduce peak load based on customer priority, and ensure that the consumption does not exceed the specified value. The algorithm's accuracy is demonstrated by several situations of consumption in the home, where the algorithm was able to lower consumption by up to 39.5% when compared to consumption without utilizing the suggested algorithm.

Authors

Ahmed Sabry Abd Elwahed,Abdelhalim Zekry,Ghada Mohamed Amer,Radwa M Tawfeek

Journal

Journal of Computing and Communication

Published Date

2022/2/1

All-Pass Filters as a Low-Complexity PAPR Reduction Scheme for SC-FDMA System

This paper presents a low-complexity peak-to-average power ratio (PAPR) reduction scheme for single-carrier frequency division multiple access (SC-FDMA) system that is based on all-pass filters (APFs). The basic idea of the APF scheme is that it allows a flat magnitude response with a non-linear phase response. This means that this type of filters passes all frequency content of the input signal, while the phase is severely or intentionally degraded. This idea is well-exploited in this paper for generating random phase sequences that can be treated as multiple versions of an input sequence for the SC-FDMA system. The heart of traditional PAPR reduction techniques such as the conventional selective mapping and blind selective mapping schemes is the generation of multiple random phase sequences for the proper selection of the sequence that achieves the minimum PAPR. This can be accomplished through …

Authors

Mohamed A Abdelhamed,Abdelhalim Zekry,Salah S Elagooz,Fathi E Abd El-Samie

Journal

Wireless Personal Communications

Published Date

2022/5

10 GHz Compact Shunt-Diode Rectifier Circuit Using Thin Film Ag/AZO Schottky Barrier Diode for Energy Harvesting Applications

A single layer microstrip diode rectifier circuit with a flexible thin film schottky diode is proposed. A compact half wave rectifier with a shunt-diode configuration is designed and implemented using off-shelf SMS-7630 low barrier Schottky diode tuned for a centre frequency of 10 GHz and fabricated one using 0.81 mm Rogers (RO4003c) substrate. The rectifier circuit with the commercial diode has a maximum conversion efficiency of 41% with 300 Ω load resistance. Al-doped-ZnO (AZO) semiconductor nanoparticle ink is used to fabricate a flexible thin film Schottky diode (TFSD). The proposed TFSD device consists of 3 layers, Ag/AZO/Cu and fabricated by deposition of a thin film of nanoparticle-ink AZO on a flexible copper tape substrate then applying an Ag electrode on the AZO to obtain the Schottky barrier diode with an active area of 1 mm2. Measurements shows that the 280 nm thickness device has the maximum …

Authors

Dalia Sadek,Abdelhalim Zekry,Heba Shawkey,Somaya Kayed

Published Date

2022/6/16

Improving the Frequency Stability of TA (NIS) Using EMD

The average atomic Time Scale (TS) of the National Institute of Standards (NIS), Egypt ((TA(NIS)) was simulated using an ensemble of only two Cesium (Cs) atomic clocks with the master clock. It was found from simulation results that the frequency stability of TA(NIS) is limited with that of the best Cs clock in the ensemble, due to the limited number of Cs clocks in the ensemble. In this paper, Empirical Mode Decomposition (EMD), as a promising method for signal processing, was utilized in improving the frequency stability of TA(NIS) by a factor of 24% by Cs clock signal de-noising. Also, Kalman Filter (KF), as a well-known signal processing method worldwide at Time and Frequency metrology was used for the same purpose. The frequency stability of TA(NIS) with both EMD and KF was compared. The findings reveal that the simple, adaptive, and efficient EMD shows comparable performance to the complicated KF …

Authors

Aly I Mostafa,Abdelhalim Zekry

Published Date

2022/7/13

Investigation of electron transport material-free perovskite/CIGS tandem solar cell

Tandem solar cells have a superb potential to push the power conversion efficiency (PCE) of photovoltaic technologies. They can be also more stable and economical. In this simulation work, an efficient perovskite solar cell (PSC) with Spiro-OMeTAD as a hole transport material (HTM) and with no electron transport material (ETM) to replace the traditional PSC structure is presented. This PSC is then used as a top sub cell together with a copper indium gallium sulfide (CIGS) bottom sub cell to build a tandem cell. The multi-junction solar cell behavior is improved by engineering the technological and physical parameters of the perovskite and HTM. The results show that an n-p heterojunction PSC structure with an ETM free could be a good candidate for the traditional n-i-p structure. Because of such investigations, the performance of the proposed ETM-free PSC/CIGS cell could be designed to reach a PCE as high as 35.36%.

Authors

Mostafa M Salah,Abdelhalim Zekry,Ahmed Shaker,Mohamed Abouelatta,Mohamed Mousa,Ahmed Saeed

Journal

Energies

Published Date

2022/8/30

Convolutional neural network model for spectrum sensing in cognitive radio systems

Cognitive radio (CR) has become an interesting research field that attracts researchers due to its increasing spectrum efficiency. Therefore, spectrum sensing (SS) is the essential function of cognitive radio systems. This paper presents an efficient SS model based on convolutional neural networks (CNNs). We use the spectrogram images of the received signals as the input to the CNN and use various images for signal and noise at different low primary‐user (PU) signal‐to‐noise ratios (SNRs) to train the network model. The model extracts the main features from the spectrogram images to represent signals and noise. Hence, this model can efficiently discriminate between signal and noise at different SNRs. The detection performance of the suggested model is compared with those of the traditional one‐stage, two‐stage SS methods, and different previous CNN models. The obtained outcomes demonstrate that the …

Authors

Walid El‐Shafai,Ahmed Fawzi,Ahmed Sedik,Abdelhalim Zekry,Ghada M El‐Banby,Ashraf AM Khalaf,Fathi E Abd El‐Samie,Mohammed Abd‐Elnaby

Journal

International Journal of Communication Systems

Published Date

2022/4

Raspberry pi design and hardware implementation of fuzzy-PI controller for three-phase grid-connected inverter

A photovoltaic system is one of the major sources of renewable energy. The grid-connected inverter controllers play an important role in the conversion and transmission of solar energy. Therefore, they must be improved to meet the demands for grid interconnection. This article introduces the design and hardware implementation of the intelligent fuzzy-PI controller of the inverter part of the grid-connected photovoltaic system. First, the paper discusses the design of the three-phase grid-connected fuzzy-PI controller. Next, the paper describes the implementation of a Matlab graphical user interface (GUI) to design any grid-connected inverter and size the photovoltaic systems. The code generation of the fuzzy-PI controller of the system is accomplished by using Matlab Simulink simulation software. The hardware components of the PV system are implemented experimentally. In the hardware implementation, a 70 W prototype is realized to test the functionality of the controller, such that one can develop a realistic controller without taking risks or falling into security concerns in the case of performing experiments on high-power systems. The prototype proves that the controller model can be directly transformed from Simulink to the control device. It also shows that the fuzzy-PI controller is working properly in the 70-watt prototype. The achieved performance parameters of the proposed fuzzy-PI controller are satisfactory. The proposed method to design and implement the fuzzy-PI controller does not require complicated programming, where a Matlab coder is proposed to transform the Simulink controller into C code that can be directly utilized as a …

Authors

Sameh Mostafa,Abdelhalim Zekry,Ayman Youssef,Wagdi Refaat Anis

Journal

Energies

Published Date

2022/1/24

Simulation of High open-circuit voltage Perovskite/CIGS-GeTe tandem cell

This research work aims to improve the performance of the tandem solar cells based on a novel design that uses perovskite material as an absorber layer of the top sub-cell and Copper indium gallium selenide (CIGS) and Germanium telluride (GeTe) materials as absorber layers of the bottom sub-cell. Using two different materials with different energy gaps and distinct doping levels as absorbers of the bottom sub-cells leads to improvement of the sub-cell performance. These two absorbers, of the bottom sub-cell layers, act electrically series-connected, which improves the sub-cell voltage but at the same time limits the current density of the sub-cell to the minimum one of the used materials. After studying the performance of both sub-cells with AM 1.5 incident spectrum at room temperature, both are used to configure Perovskite/CIGS-GeTe tandem cells. The performance of the designed tandem cell was studied to …

Authors

Mohamed Mousa,Mostafa M Salah,A Zekry,Mohamed Abouelatta,Ahmed Shaker,Fathy Z Amer,Roaa I Mubarak,Ahmed Saeed

Published Date

2022/6/5

Performance Investigation of a Proposed Flipped npn Microstructure Silicon Solar Cell Using TCAD Simulation

This work aims at inspecting the device operation and performance of a novel flipped npn microstructure solar cell based on low-cost heavily doped silicon wafers. The flipped structure was designed to eliminate the shadowing effect as applied in the conventional silicon-based interdigitated back-contact cell (IBC). Due to the disappearance of the shadowing impact, the optical performance and short-circuit current density of the structure have been improved. Accordingly, the cell power conversion efficiency (PCE) has been improved in comparison to the conventional npn solar cell microstructure. A detailed analysis of the flipped npn structure was carried out in which we performed TCAD simulations for the electrical and optical performance of the flipped cell. Additionally, a comparison between the presented flipped microstructure and the conventional npn solar cell was accomplished. The PCE of the conventional npn structure was found to be 14.5%, while it was about 15% for the flipped structure when using the same cell physical parameters. Furthermore, the surface recombination velocity and base bulk lifetime, which are the most important recombination parameters, were studied to investigate their influence on the flipped microstructure performance. An efficiency of up to 16% could be reached when some design parameters were properly fine-tuned. Moreover, the impact of the different physical models on the performance of the proposed cell was studied, and it was revealed that band gap narrowing effect was the most significant factor limiting the open-circuit voltage. All the simulations accomplished in this analysis were carried out using …

Authors

Marwa S Salem,Abdelhalim Zekry,Ahmed Shaker,Mohamed Abouelatta,Mohamed M ElBanna,Tariq S Almurayziq,Rabie A Ramadan,Mohammad T Alshammari

Journal

Crystals

Published Date

2022/7/9

Analysis of an Efficient ZnO/GeTe Solar Cell Using SCAPS-1D

Most of the solar cells that dominate the market are single-junction solar cells. These solar cells use mainly silicon, and some of them use relatively new materials like copper, indium, gallium, selenide (CIGS) and perovskite. These materials show a good performance, but they have a limitation of performance and are also costly or unstable. The strategy for improving the performance of single-junction solar cells in this paper is based on the use of promising material. The proposed single-junction solar cell uses germanium telluride (GeTe) as an absorber layer and zinc oxide (ZnO) as an electron transport layer. Germanium telluride has main advantages compared to many materials. It has a high electrical conductivity and a small energy gap, allowing it to absorb a larger portion of the input spectrum. The cell shows a 21.58% power conversion efficiency at room temperature using input spectrum air mass (AM 1.5 …

Authors

Mostafa M Salah,A Zekry,Mohamed Abouelatta,Ahmed Shaker,Mohamed Mousa,Ahmed Saeed

Published Date

2022/8/3

Efficient PAPR Reduction Method for FBMC based Systems Using Isosceles Trapezoidal Distribution Transforms

ABSTRACT Filter Bank Multicarrier with Offset Quadrature Amplitude Modulation (FBMC/OQAM) has been one of the key proposed candidate methods for fifth-generation wireless communication and beyond systems (5G) due to its many attractive properties and features related to spectral confinement. However, the applicability of the FBMC/OQAM modulation method is limited mainly by its high peak to average power ratio (PAPR), which can significantly reduce system efficiency. In this paper, a new technique based on the Isosceles Trapezoidal Distribution Transform (ITDT) is proposed to reduce the PAPR of FBMC/OQAM transceiver by transforming original Gaussian distributed FBMC signals into an Isosceles Trapezoidal, while maintaining a constant average output power level. The general formulas of the proposed scheme are derived and the trade-off between PAPR reduction and BER performance is accomplished by properly choosing variable parameters which are required for controlling the nonlinearity of the Companding function used in the proposed technique. The presented simulation results demonstrate that the proposed scheme can offer substantially better overall performance for FBMC based systems in terms of PAPR reduction, BER performance, and bandwidth efficiency compared to the other competitive methods.

Authors

Imad Shaheen,Abdelhalim Zekry

Journal

RS Open Journal on Innovative Communication Technologies

Published Date

2022/3/23

Design and simulation of ETL-free Perovskite/Si tandem cell with 33% efficiency

Multi-junction (tandem) cell using MAPbI3-xClx and silicon as absorbers has been designed and simulated in this paper. The thickness of the silicon layer in the bottom cell is 2 μm allowing it to absorb the transmitted spectrum from the perovskite subcell as much as possible. The thickness of the MAPbI3-xClx layer is optimized using a proposed algorithm. The output metrics show that the optimum thickness of the MAPbI3-xClx layer was 205 nm. The simulation outputs showed that the proposed tandem cell has an efficiency of 33.09% with an open circuit voltage of 1.9 V and a short circuit current of 19.95 mA/cm2.

Authors

Ahmed Saeed,Mohamed Mousa,MOSTAFA M Salah,A Zekry,MOHAMED Abouelatta,AHMED Shaker,Fathy Z Amer,Roaa I Mubarak

Journal

WSEAS Trans. Electron

Published Date

2022

Efficient self-protected thin film c-Si solar cell against reverse-biasing condition: A simulation study

In order to protect the solar panel against reverse biasing, bypass Schottky diodes are usually connected in parallel with a string of cells which makes the circuit more complex and costly. This study presents a novel thin-film crystalline silicon device design using physics-based TCAD simulations. In our proposed solar cell, a P + reverse conducting layer is introduced to form an N ++ /P + /P structure. The novel device structure provides two different functions depending on the type of applied bias. It operates as an efficient solar cell when operating at forward biasing while it acts as a backward diode when reverse biased. Therefore, such a proposed device is self-protected against the reverse current. Also, it can reduce circuit complexity and manufacturing cost.

Authors

Omar M Saif,Abdelhalim Zekry,Ahmed Shaker,M Abouelatta,Ahmed Saeed

Published Date

2022/6/5

Controlled Redundancy Schemes in Collaborative IoT by Smartphones.

Internet of Things (IoT) operators tend to utilize smartphones in establishing reliable and sustainable communication links for their services. Collaborative IoT (CIoT) is a concept where the smartphones are utilized as a mobile gateway (GW) that connects sensors to the cloud. CIoT scheme has many challenges including the redundancy in transmissions of sensor readings. As the same sensor data is sent by many uncoordinated users, this leads to consuming network resources and degrading Quality of Services (QoS) for primary users. This paper has three main contributions: First, four metrics for evaluating redundancy and its effects in CIoT network are defined and explained. Second, a novel redundancy control scheme (Fresh-List redundancy control) is proposed and evaluated against well-known probabilistic transmission schemes using the proposed metrics. Finally, a simulation setup for CIoT environment is implemented using a computer equipped with Bluetooth network card. The setup simulates many CIoT users with different scenarios of random entry, departure, and dwelling times. Results show the ability of Fresh-List method to reduce redundancy order and increase efficiency compared to noncontrolled redundancy. It is also shown that a mix between probabilistic transmission and Fresh-List methods provide even more better redundancy control at an acceptable increase at the average packet delivery delay.

Authors

Mohamed A Marzouk,Ayman M Hassan,Abdelhalim A Zekry

Journal

J. Commun.

Published Date

2022/7

An Overview of the Development of Speaker Recognition Techniques for Various Applications.

Speech Enhancement (SE) is a significant research issue in audio signal processing where the goal is to enhance the clarity and quality of speech signals corrupted by noise. Because of its different applications, it becomes a compelling research topic nowadays. The focus of this paper is dedicated to one of these applications which is Speaker recognition. In this paper, the fundamentals and applications of speaker recognition are discussed. A brief study on the performance and the recognition accuracy of different speaker modeling techniques has been conducted. Furthermore, while there have been several studies about the technologies used in speaker recognition, there have been few studies about the applications of speaker recognition, and none of them considers combining or linking the applications and technology in the same study. This overview demonstrates the various technologies that can be used to achieve speaker recognition applications. It aims to give a new perspective of the existing technologies uses in various applications. The paper concludes with discussions on future trends and research opportunities in this area.

Authors

Amira A Mohamed,Amira Eltokhy,Abdelhalim A Zekry

Published Date

2022/8

A Study on the Basics Processes of Massive MIMO.

Massive Multiple Input Multiple Output (MIMO) is a key technique used in 5G mobile communication systems; it aims to efficiently increase the spectral efficiency of the communication systems. Massive MIMO is a MIMO system with a massive number of antennas in the base station, it uses its large number of antennas to efficiently transmit and receive the signals between the base stations and the user equipment and maximize the spectral efficiency of the system. Massive MIMO is mainly composed of three important processes: channel estimation, uplink transmission (receive beamforming), and downlink transmission (transmit beamforming). Based on the effective channel estimation methods, the base station can process the signal to make efficient transmit and receive beamforming and provide good transmission and reception quality, which is measured by the spectral efficiency of the system. Many references present the basics of massive MIMO processes, including channel estimation, transmit beamforming and receive beamforming. This paper aims to present a cleared and concluded study on these basics massive MIMO processes. It presents different channel estimation methods and evaluates its performance based on the normalized mean square error. It also presents different receive and transmit beamforming techniques and evaluates its performance based on spectral efficiency.

Authors

Marwa Abdelfatah,Shaimaa ElSayed,Abdelhalim Zekry

Journal

J. Commun.

Published Date

2022/3

Investigation of lead-free MASnI3-MASnIBr2 tandem solar cell: Numerical simulation

Lead-free perovskite materials have attracted noteworthy interest for photovoltaics as they are free from toxicity and instability issues encountered in lead-based perovskites. In this work, we report on a simulation study of a two-terminal monolithic all lead-free tandem solar cell. The (MASnI3) cell with 1.3 eV bandgap is used as a bottom cell and the top cell is (MASnIBr2) with a bandgap of 1.75 eV. The calibration of the standalone bottom and top cells initially gives a conversion power efficiency (PCE) of 5.42% and 5.74%, respectively. After comprising these two initial sub-cells in a two-terminal all lead-free monolithic tandem cell, a tandem efficiency of 7.66% is obtained with a matching current is 10.36 mA/cm2 in this case. Based on parametric analysis, the values of perovskite doping, perovskite defect density and ETL/HTL affinity are optimized. The PCE of individual cells after enhancement has increased to 11.01 …

Authors

S Abdelaziz,A Zekry,A Shaker,MJOM Abouelatta

Journal

Optical Materials

Published Date

2022/1/1

Validation and Evaluation of a Behavioral Circuit Model of an Enhanced Electrostatic MEMS Converter

In this current study, the validation and evaluation of a behavioral circuit model of electrostatic MEMS converters are presented. The main objective of such a model is to accurately find the converter behavior through the proper choice of its circuit elements. In this regard, the model enables the implementation of the electrostatic MEMS converter using commercially available off-shelf circuit elements. Thus, the overall vibration energy harvesting system can be implemented and tested without the need for fabricating the converter. As a result, the converter performance can be verified and evaluated before its fabrication which saves the expenses of fabricating trailed prototypes. To test the model, we apply it to an enhanced converter in which the conventional electrostatic MEMS converter is modified by depositing the tantalum pentoxide, Ta2O5, a high dielectric constant material, on its fingers’ sidewalls. Such a deposition technique causes an appreciable increase in the overall converter capacitance and, in turn, the output power, which is boosted from the range of µw to the range of mW. Next, the converter behavioral circuit model, which is based on representing its capacitances variations with respect to the input displacement, x caused by the vibration signal, C–x curve, is built up. The model is qualitatively validated and quantitatively evaluated. The enhanced converter performance is investigated through the interaction of its model with the power conditioning circuit. From the simulation results, it is revealed that the converter behavioral circuit model accurately accomplishes the vibration energy conversion operation. As a result, the specification …

Authors

Mona S Salem,Abdelhalim Zekry,Mohamed Abouelatta,Ahmed Shaker,Marwa S Salem

Journal

Micromachines

Published Date

2022/5/31

High-Efficiency Electron Transport Layer-Free Perovskite/GeTe Tandem Solar Cell: Numerical Simulation

The primary purpose of recent research has been to achieve a higher power conversion efficiency (PCE) with stable characteristics, either through experimental studies or through modeling and simulation. In this study, a theoretical analysis of an efficient perovskite solar cell (PSC) with cuprous oxide (Cu2O) as the hole transport material (HTM) and zinc oxysulfide (ZnOS) as the electron transport material (ETM) was proposed to replace the traditional HTMs or ETMs. In addition, the impact of doping the perovskite layer was investigated. The results show that the heterostructure of n-p PSC without an electron transport layer (ETL) could replace the traditional n-i-p structure with better performance metrics and more stability due to reducing the number of layers and interfaces. The impact of HTM doping and thickness was investigated. In addition, the influence of the energy gap of the absorber layer was studied. Furthermore, the proposed PSC without ETL was used as a top sub-cell with germanium-telluride (GeTe) as a bottom sub-cell to produce an efficient tandem cell and boost the PCE. An ETL-free PSC/GeTe tandem cell is proposed for the first time to provide an efficient and stable tandem solar cell with a PCE of 45.99%. Finally, a comparison between the performance metrics of the proposed tandem solar cell and those of other recent studies is provided. All the simulations performed in this study are accomplished by using SCAPS-1D.

Authors

Mostafa M Salah,Abdelhalim Zekry,Mohamed Abouelatta,Ahmed Shaker,Mohamed Mousa,Fathy Z Amer,Roaa I Mubarak,Ahmed Saeed

Journal

Crystals

Published Date

2022/6/21

Internet of things based energy management system using real-time consumption data

Egypt is one of Africa's and the Arab world's most populous countries, with overcrowding and one of the world's fastest-growing economies. The rapid growth of the population led to a rapid rise in energy demand, placing pressure on the country's domestic energy resources in the residential sector. The home energy management system design aims to shed light on the current status of traditional home appliances in Egypt and connect them to the internet and control them remotely by using mobiles, tablets, or laptops.This paper will describe an IoT-based home energy management system for controlling and managing energy use. The system prototype is designed and utilized to handle real consumption in order to achieve minimum power consumption and ensure a whole house is under the value of a specific demand limit in order to lower peak load based on customer priority.As shown through various scenarios …

Authors

Ahmed S Abdelwahed,Abdelhalim Zekry,Ghada Mohamed Amer,Radwa M Tawfeek

Published Date

2022/7/26

A reconfigurable class-F radio frequency voltage doubler from 650 MHz to 900 MHz for energy harvesting applications

This paper presents a reconfigurable high efficiency, high output voltage, and multiband class-F radio frequency (RF) voltage doubler and two stages voltage doubler rectifiers for energy harvesting applications using RO4003C substrate. The proposed voltage-doubler circuits are suitable for multi-band LTE, IoT, WSN, UHF ISM 900 MHz, GSM 900, energy harvesting, and multi-standard applications. The voltage doubler circuits are implemented using the Schottky diode (HSMS2852). Also, the voltage-doubler circuits are optimized and refabricated to recompense the unwanted parasitic and achieve the required performance. The voltage doubler and two stages voltage doubler rectifiers have a measured efficiency exceeding 40% in the frequency band from 650 MHz to 900 MHz at −10dBm input power and a load resistance of 10kohm, 22kohm, and an output voltage of 1 V at −10dBm input power. The proposed …

Authors

Marwa Mansour,Islam Mansour,Abdelhalim Zekry

Journal

Alexandria Engineering Journal

Published Date

2022/10/1

Effect of temperature on the electrical parameters of indium phosphide/aluminum gallium indium phosphide (InP/AlGaInP) quantum dot laser diode with different cavity lengths

The IV characteristics of InP/AlGaInP quantum dot laser diodes with different cavity lengths were measured at different temperatures (77–400K). From the forward bias IV characteristics, the laser diode electrical parameters, as the ideality factor (n), the reverse saturation current (Js), and series resistance (Rs) were extracted. The values of the ideality factor depend slightly on the temperature in the temperature range above 150 K while it increases as the temperature decreases below this value. It is noticed that the increase of n for a longer cavity is greater. This may be attributed to the freezing out of the mobile charge carriers in the n and p emitters of the diode. Conversely, Js increases with the temperature. It follows almost an exponential increase with temperature most probably because of the thermal generation of electron-hole pairs across the energy gap of the material. Rs behaves in a similar way where it is almost constant at T> 150 K. It appreciably increases with further lowering the temperature with the shortest cavity having the greatest increase. Rs decreases as the cavity length increases. This may again be attributed to the freeze out or the mobile charge carriers in the end emitter regions of the device. For our best knowledge such results are reported for the first time for these diodes.

Authors

FA Al-Marhaby,MS Al-Ghamdi,Abdelhalim Zekry

Journal

Engineered Science

Published Date

2022/2/8

Implementation of surface electromyography controlled prosthetics limb based on recurrent neural network

Low‐cost traditional prosthetic legs, available worldwide, can make walking and stair climbing possible but still difficult. This article presents the hardware implementation of the surface electromyography (sEMG) powered prosthesis actuation (PPA) system using a learned neural network algorithm based on recurrent neural network (RNN), which is used to train sEMG benchmark databases, and predict joint angle. This implementation was created based on sEMG signal measurements. The data were collected from three benchmark datasets describing different subjects during performance, and analyzing various gait patterns were used to construct the neural network and reduce significant model errors in a real‐time setting. Processing circuits, interfacing the output with the controller board, signal amplification, motor driving circuits, and single‐board computer programming are included in the implementation.

Authors

Tarek M Bittibssi,Abdelhalim Zekry,Mohamed A Genedy,Shady A Maged

Journal

Concurrency and Computation: Practice and Experience

Published Date

2022/5/15

A 2× 2 Array Antenna for Multi-band Energy Harvesting for Biomedical Sensing Applications

A novel multi-band planar 2× 2 array loop antenna, with a frequency ranging from 0.5–4.5 GHz for energy harvesting applications is presented. The proposed loop antenna consists of an external strip loop and an internal banana strip connected to the external strip loop. The loop antenna occupies a small size of 62× 38 mm2, while the total area of the suggested array antenna is 164× 80 mm2. A prototype of the proposed 2× 2 array antenna is fabricated, measured, and the results including return loss, efficiency, and gain, are obtained, and characterized. Therefore, excellent agreement was found between the measured and simulated results.

Authors

Abdelhalim Zekry

Journal

Design, Operation and Evaluation of Mobile Communications: Third International Conference, MOBILE 2022, Held as Part of the 24th HCI International Conference, HCII 2022, Virtual Event, June 26–July 1, 2022, Proceedings

Published Date

2022/6/16

A reconfigurable class-ab/f power amplifier for 0.1–4.2 GHz multistandard applications

In this paper, a reconfigurable multi-mode Class-AB/F power amplifier (PA) is proposed for 0.1–4.2 GHz multistandard applications. The PA operates in linear mode (class-AB) for variable-envelope modulated signals and switching mode (class-F) for constant-envelope modulated signals. The proposed linear mode PA design is suitable for multi-band LTE, IOT, WSN and multi-standard RF transmitter, while switching mode PA design can be used in multi-band IOT-LPWA and BLE (Bluetooth Low Energy) RF transmitter. The proposed PA has a reconfigurable off-chip inter-stage and output matching networks over the specified frequency band, while the input stage is Complementary Current-Reuse common-gate with active shunt feedback configuration to achieve Ultra-Wideband (UWB) input matching. The proposed multi-mode PA is designed using a 130 nm CMOS process. Class-AB PA has a saturated …

Authors

Marwa Mansour,Abdelhalim Zekry,Mohammed K Ali,Heba Shawkey

Journal

Circuits, Systems, and Signal Processing

Published Date

2021/3

Nested code division multiple access for distance measuring equipment interference mitigation in L‐band digital aeronautical communication system

Air‐to‐ground (A/G) communications have been transferred from the congested very high frequency (VHF) band to occupy the guard bands between adjacent distance measurement equipment (DME) navigation channels within the L‐Band. However, the inlayed channels, called L‐band digital aeronautical communication system (LDACS) channels, experience severe interference with the coexisting DME channels. In this paper, a DME interference detection and mitigation technique is proposed to improve the performance of the LDACS in the presence of DME interference. The DME energy detector based on Neyman–Pearson test is proposed, which has more advantages than the other techniques due to its noncoherent nature and simplicity. Furthermore, the proposed DME detection technique is performed by using an adaptive threshold to achieve the best trade‐off between the DME signal detection and false …

Authors

Emad Abd‐Elaty,Abdelhalim Zekry,Salah El‐Agooz,Anwar M Helaly

Journal

International Journal of Communication Systems

Published Date

2021/6

Compact and high-efficiency rectenna for wireless power-harvesting applications

A compact, single-layer microstrip rectenna for dedicated far-field RF wireless power-harvesting applications is presented. The proposed rectenna circuit configurations including multiband triple L-Arms patch antenna with diamond slot ground are designed to resonate at 10, 13, 17, and 26 GHz with 10 dB impedance bandwidths of 0.67, 0.8, 2.45, and 4.3 GHz, respectively. Two rectifier designs have been fabricated and compared, a half wave rectifier with a shunted Schottky diode and a voltage doubler rectifier. The measured and simulated maximum conversion efficiencies of the rectifier using the shunted diode half-wave rectifier are 41%, and 34%, respectively, for 300 Ω load resistance, whereas they amount to 50% and 43%, respectively, for voltage doubler rectifier with 650 Ω load resistance. Compared to the shunted rectifier circuit, it is significant to note that the voltage doubler rectifier circuit has higher efficiency. Both rectifier’s circuits presented are tuned for a center frequency of 10 GHz and implemented using 0.81 mm thick Rogers (RO4003c) substrate. The overall size of the antenna is 16.5 × 16.5 mm2, and the shunted rectifier is only 13.3 × 8.2 mm2 and 19.7 × 7.4 mm2 for the voltage doubler rectifier. The antenna is designed and simulated using the CST Microwave Studio Suite (Computer Simulation Technology), while the complete rectenna is simulated using Agilent’s ADS tool with good agreement for both simulation and measurements.

Authors

Dalia H Sadek,Heba A Shawkey,Abdelhalim A Zekry

Journal

International Journal of Antennas and Propagation

Published Date

2021/12/15

State‐of‐the‐Art and Prospective of Solar Cells

Today, advances and improvements in solar cells have been caused to emerge cost‐effective with high PCE solar cells. They are ideal candidates for commercial devices and applications especially power plants, satellites and so on. Progress in solar cells have helped in solving PV problems and opened the doors to future discoveries. This chapter addresses these progresses from 1954 to 2020 to offer the latest evolution as well as coming PV cell prospects. So, total developments in this field have been presented. Additionally, this chapter has introduced the sustainability of solar energy.

Authors

Zahra Pezeshki,Abdelhalim Zekry

Journal

Fundamentals of Solar Cell Design

Published Date

2021/8/5

A self-powered wearable wireless sensor system powered by a hybrid energy harvester for healthcare applications

In this paper, a wearable medical sensor system is designed for long-term healthcare applications. This system is used for monitoring temperature, heartbeat, blood oxygen saturation (SpO2), and the acceleration of a human body in real-time. This system consists of a temperature sensor, a pulse oximeter sensor, an accelerometer sensor, a microcontroller unit, and a Bluetooth low energy module. Batteries are needed for supplying energy to this sensor system, but batteries have a limited lifetime. Therefore, a photovoltaic–thermoelectric hybrid energy harvester is developed to power a wearable medical sensor system. This harvester provides sufficient energy and increases the lifetime of the sensor system. The proposed hybrid energy harvester is composed of a flexible photovoltaic panel, a thermoelectric generator module, a DC–DC boost converter, and two super-capacitors. Experimentally, in active …

Authors

Saeed Mohsen,Abdelhalim Zekry,Khaled Youssef,Mohamed Abouelatta

Journal

Wireless Personal Communications

Published Date

2021/2

Influence of base doping level on the npn microstructure solar cell performance: A TCAD study

Silicon industry has a mature learning curve which is the driver for 90% share of the PV market. Yet, the cost/m2 of the planar crystalline silicon solar cell is still high. To reduce the cost of silicon-based solar cells, heavily doped wafers can be used in a proposed npn microstructure in which photoexcited carries are vertically generated while the collection of carriers is accomplished in the lateral direction. In this work, we report on the influence of the heavily p + base doping concentration, Na, on the performance of the cell for different base widths. All simulations are performed by using SILVACO TCAD under AM1.5 illumination. The results show that for Na extending from 5 × 1017 cm−3 to 2 × 1019 cm−3, the cell could achieve a competitive efficiency, from 15.4% to 9%, respectively.

Authors

Marwa Salem,A Zekry,M Abouelatta,Mohammad T Alshammari,Adwan Alanazi,Kawther A Al-Dhlan,A Shaker

Journal

Optical Materials

Published Date

2021/11/1

Implementation of a Priority-Based Home Energy Management System

The increasing number of home appliances and the variation of technologies between them (modern or smart and legacy or old) is the reason for homes energy problem. In addition, increasing the peak load of grids facilities often causes electricity cuts of homes' sectors to reduce the overloads due to peak load. All of these reasons lead to use the energy management systems to reduce energy consumption and automatic control of home appliances to reduce billing for consumers, as well as utilities and decrease peak and peak-to-peak demand. In this paper, an energy management system to automatically control energy of home appliances will be presented, by using MATLAB software simulation and by hardware using a Microcontroller through prototype to analyze the Demand Response. The proposed algorithm will handle consumption to achieve minimum power cost, decrease peak load according to the …

Authors

Ahmed S Abdelwahed,Abdelhalim Zekry,Ghada Mohamed Amer,Radwa M Tawfeek

Published Date

2021/5/26

Spectrum measurement and utilization in an outdoor 5‐GHz Wi‐Fi network using cooperative cognitive radio system

Nowadays, the popular 2.4‐GHz band is used in different systems, such as Wi‐Fi, Bluetooth, wireless sensor systems, and wireless cameras. Instead of the over‐crowded 2.4‐GHz Wi‐Fi band, this research offers the experience of using the 5‐GHz Wi‐Fi band, which provides more spectrum availability, more channels, larger bandwidth, faster data transmission, higher data rates, higher speed, and better quality of service compared to those of the 2.4‐GHz band. In this paper, practical implementation and testing of a cooperative spectrum sensing system are presented. The spectrum utilization in the 5‐GHz Wi‐Fi licensed band at six different locations is investigated to allow the transition of secondary users (SUs) to free bands. The spectrum measurement is performed on a centralized cooperative spectrum sensing system, which consists of a master cognitive radio node and five cognitive radio stations. The …

Authors

Walid El‐Shafai,Ahmed Fawzi,Abdelhalim Zekry,Fathi E Abd El‐Samie,Mohammed Abd‐Elnaby

Journal

International Journal of Communication Systems

Published Date

2021/7/10

Investigation of base high doping impact on the npn solar cell microstructure performance using physically based analytical model

Recently, there is a rapid trend to incorporate low cost solar cells in photovoltaic technology. In this regard, low-cost high-doped Silicon wafers are beneficial; however, the high doping effects encountered in these wafers render their practical use in fabrication. The npn solar cell microstructure has been found to avoid this issue by the proper design of vertical generation and lateral collection of the light generated carriers. We report on the impact of the p + base doping concentration, up to 2 × 10 19 cm -3 , on the npn microstructure performance to find the most appropriate way for high efficiency. To optimize the structure, a series of design steps has been applied using our previously published analytical model. Before inspecting the high doped base effect, firstly, the n + emitter is optimized. Secondly, the impact of bulk recombination inside the p + base is introduced showing the range of optimum base width (W p …

Authors

Marwa SS Basyoni,A Zekry,Ahmed Shaker

Journal

IEEE Access

Published Date

2021/1/22

Multiband triple L-arms patch antenna with diamond slot ground for 5G applications

Abstract─ This paper reported a pioneering 5G multiband microstrip line fed patch antenna for IoT, wireless power transfer (WPT) and data transmission. The proposed antenna is accomplished using a triple L-arms patch antenna responsible for the multiband response. A diamond-shaped ground slot is added to control and increase the bandwidth of the resonant frequency. The antenna is designed to resonate at 10, 13, 17 and 26 GHz with 10 dB impedance bandwidths of 0.67, 0.8, 2.45 and 4.3 GHz respectively. The proposed antenna is fabricated using microstrip technology with total area of 16.5 x16. 5 mm2. The 5G multiband antenna has sufficient realized gain of 4.95, 5.72, 4.94 and 7.077 dB respectively. The antenna is designed and simulated using the CST Microwave Studio Suite (Computer Simulation Technology). Measurements show good agreement with simulations in all frequencies of operation.

Authors

Dalia H Sadek,Heba A Shawkey,Abdelhalim A Zekry

Journal

Applied Computational Electromagnetics Society Journal

Published Date

2021

Low-Cost L-Band FMCW Radar for Motion Detection Behind Multiple Walls

FMCW radars were used in numerous applications in the last three decades. One important application is the human movements detection behind walls. In this paper, an FMCW low-cost radar is proposed and implemented for human motion detection behind multiple walls. A radar system is designed to operate at L-band to afford a good penetration capability with 1 GHz bandwidth to maintain a sufficient range resolution. The hardware implementation is proposed and explained. A real-time signal processor is implemented on an FPGA to enable real-time motion detection with user-configurable processing parameters. The signal processing stages are also discussed. A set of experimental tests were conducted to confirm the radar system detection capabilities. The radar could successfully provide the range profile of a walking man along a room and behind two brick walls at a range of 8 m and a resolution of 20 cm …

Authors

Kamal Hussein,Abdelhalim Zekry,Mohamed Abouelatta,Mohamed Mabrouk,Mostafa Elsayed

Published Date

2021/10/16

Development of solar cell for large area position detection: proof of concept

Detecting and analyzing a moving body position are helpful in many fields, such as medicine, sports performance, virtual reality and many more. Therefore, researchers try to develop a tool or a system that helps to detect the motion and tracking its position. This paper shows how a Si solar cell can be modified to function as a Position Sensitive Detector (PSD), which could be used as a large area detector in a position detection system. To develop the new detector, we modeled and simulated the modified solar cell by TCAD simulation tools to calculate the detected photocurrent as a function of the position of an incident laser beam sourced by the moving object. Further, an optical position detection system is implemented containing the modified solar cell, a signal amplifier and a microcontroller. The output is then displayed on a Laptop. By measuring the same simulated output photocurrents, it is found that the …

Authors

Heba Abdelmoneim,Abdelhalim Zekry,Ahmed Shaker

Journal

Heliyon

Published Date

2021/5/1

Semiconductor Materials and Modelling for Solar Cells

The book presents a comprehensive survey about advanced solar cell technologies. Focus is placed on semiconductor materials, solar cell efficiency, improvements in surface recombination velocity, charge density, high ultraviolet (UV) sensitivity, modeling of solar cells etc. The book references 281 original resources with their direct web links for in-depth reading. Keywords: Solar Cells, Thin Film Solar Cells, Solar Cell Efficiency, Semiconductor Materials, Surface Recombination Velocity, Charge Density, High UV Sensitivity, Heavily-doped Silicon Wafers, Amorphous Semiconductors, Nanocrystalline Semiconductors, Field Effect, Ferroelectric Semiconductors, Solar Cell Modelling.

Authors

Z Pezeshki,A Zekry

Published Date

2021/7/5

Research Article Compact and High-Efficiency Rectenna for Wireless Power-Harvesting Applications

A compact, single-layer microstrip rectenna for dedicated far-field RF wireless power-harvesting applications is presented. e proposed rectenna circuit configurations including multiband triple L-Arms patch antenna with diamond slot ground are designed to resonate at 10, 13, 17, and 26 GHz with 10 dB impedance bandwidths of 0.67, 0.8, 2.45, and 4.3 GHz, respectively. Two rectifier designs have been fabricated and compared, a half wave rectifier with a shunted Schottky diode and a voltage doubler rectifier. e measured and simulated maximum conversion efficiencies of the rectifier using the shunted diode half-wave rectifier are 41%, and 34%, respectively, for 300 Ω load resistance, whereas they amount to 50% and 43%, respectively, for voltage doubler rectifier with 650 Ω load resistance. Compared to the shunted rectifier circuit, it is significant to note that the voltage doubler rectifier circuit has higher efficiency. Both rectifier’s circuits presented are tuned for a center frequency of 10GHz and implemented using 0.81 mm thick Rogers (RO4003c) substrate. e overall size of the antenna is 16.5× 16.5 mm2, and the shunted rectifier is only 13.3× 8.2 mm2 and 19.7× 7.4 mm2 for the voltage doubler rectifier. e antenna is designed and simulated using the CST Microwave Studio Suite (Computer Simulation Technology), while the complete rectenna is simulated using Agilent’s ADS tool with good agreement for both simulation and measurements.

Authors

Dalia H Sadek,Heba A Shawkey,Abdelhalim A Zekry

Published Date

2021

NB‐IoT optimisation: Holistic view for smart cities applications with smart meters networks case study

The future demands for smart‐cities applications impose maximising the resources utilisation. This study achieves two main objectives to comply with fifth‐generation networks goals. First one is to enhance the Narrowband‐Internet of Things (NB‐IoT) spectral‐efficiency. The second is to alleviate the burden of two issues: The signalling during each transmission request for smart‐meters (SM) and queuing burden. First, we model the uplink scheduler for the NB‐IoT access network using state‐machine modelling methodology on Simulink environment. The simulation result is verified and validated with trusted modelling technique. Second, we optimise the NB‐IoT uplink scheduler which exploits the periodicity nature of SMs applications with putting envisage considering the emergency conditions. This is done by proposing integrated scheduling protocol which classifies the IoT traffic types and rearranges the …

Authors

Ahmed M Abbas,Khaled Y Youssef,Abdelhalim Zekry,Imbaby I Mahmoud

Journal

IET Communications

Published Date

2021/1

On the investigation of interface defects of solar cells: lead-based vs lead-free perovskite

Perovskite solar cells (PSCs) have drawn significant consideration as a competing solar cell technology because of the drastic advance in their power conversion efficiency (PCE) over the last two decades. The interfaces between the electron transport layer (ETL) and the absorber layer and between the absorber layer and the hole transport layer (HTL) have a major impact on the performance of the PSCs. In this paper, we have investigated the defect interfaces between ETL/absorber layer and absorber layer/HTL of calibrated experimental CH 3 NH 3 PbX 3 lead-based and FASnI 3 lead-free PSCs. The influence of the defect interfaces is studied in order to find the optimum value for the maximum possible PCE. While the PCE has not been enhanced considerably for the lead-based, it is boosted from 1.76% to 5.35% for lead-free PSCs. Also, bulk traps were found to have minor role in comparison with interface …

Authors

Marwa Sayed Salem Basyoni,Mostafa M Salah,Mohamed Mousa,Ahmed Shaker,Abdelhalim Zekry,Mohamed Abouelatta,Mohammad T Alshammari,Kawther A Al-Dhlan,Christian Gontrand

Journal

IEEE Access

Published Date

2021/9/20

Analysis and Design of a 5G Multi-Mode Power Amplifier using 130 nm CMOS technology

This work proposes a dual-mode radio frequency (RF) power amplifier (PA) for the 4.8 GHz multi-standard applications using a 130 nm CMOS technology. The proposed RF power amplifier (PA) consists of two stages (driver and power). By changing the driver and the power stages bias voltages any mode of PA (class-AB∖F) can be achieved. The class-AB or linear mode power amplifier design is appropriate for IoT, LTE, 5G, and multi-standard RF transmitters. Whereas the class-F or switching mode PA is suitable for IoT-LPWAN and Bluetooth applications. The class-AB mode has a saturated output power of 23 dBm at 4.8 GHz, a power-added efficiency (PAE) of 29.5 %, an output third-order intercept point (OIP3) equals 18 dBm, and for LTE 15MHz channel bandwidth the adjacent channel power ratio (ACPR) is -36 dBc. On the other hand, the maximum PAE is 28% and the output power equals 22.3 dBm for the …

Authors

Marwa Mansour,Abdelhalim Zekry,Mohammed K Ali,Heba Shawkey

Published Date

2021/4/7

FPGA implementation of Lempel-Ziv data compression

When transmitting the data in digital communication, it is well desired that the transmitting data bits should be as minimal as possible, so many techniques are used to compress the data. In this paper, a Lempel-Ziv algorithm for data compression was implemented through VHDL coding. One of the most lossless data compression algorithms commonly used is Lempel-Ziv. The work in this paper is devoted to improve the compression rate, space-saving, and utilization of the Lempel-Ziv algorithm using a systolic array approach. The developed design is validated with VHDL simulations using Xilinx ISE 14.5 and synthesized on Virtex-6 FPGA chip. The results show that our design is efficient in providing high compression rates and space-saving percentage as well as improved utilization. The Throughput is increased by 50% and the design area is decreased by more than 23% with a high compression ratio compared to comparable previous designs.

Authors

Gody Mostafa,Abdelhalim Zekry,Hatem Zakaria

Journal

International Journal of Reconfigurable and Embedded Systems

Published Date

2021/7/1

Simulation of LTE-Advanced Downlink Physical Layer Transceiver

Due to the growing demands of mobile communication system users, higher peak data bit rates of up to 1 Gbps are being sought. As a result, the Long-Term Evolution Advanced (LTE-Advanced) as an advanced standard for mobile communication systems was created by the Third Generation Partnership Project (3GPP). On the physical layer (PYH), the most recent LTE-Advanced characteristics have been released. In addition to turbo coding, the Downlink uses Orthogonal Frequency Division Multiple Access (OFDMA), whereas the Uplink uses Single Carrier Frequency Division Multiple Access (SC-FDMA). This study uses MATLAB to simulate the LTE-Advanced PYH downlink transceiver in accordance with 3GPP Release 10. The Intra-band contiguous Carrier Aggregation type with two Component Carriers was used to replicate all steps of the LTE-Advanced downlink PYH transceiver, including Time and Frequency Synchronization in the receiver.

Authors

Sara M Hassan,Gihan G Hamza,Abdelhaliem Zekry

Journal

Communications on Applied Electronics

Published Date

2021

Analysis of hybrid hetero-homo junction lead-free perovskite solar cells by SCAPS simulator

In this work, we report on the effect of substituting the active intrinsic i-layer on a conventional pin structure of lead-free perovskite solar cell (PSC) by a homo p-n junction, keeping the thickness of the active layer constant. It is expected that when the active i-layer is substituted by a p-n homo junction, one can increase the collection efficiency of the photo-generated electrons and holes due to the built-in electric field of the homo junction. The impact of the technological and physical device parameters on the performance parameters of the solar cell have been worked out. It was found that p-side thickness must be wider than the n-side, while its acceptor concentration should be slightly lower than the donor concentration of the n-side to achieve maximum efficiency. In addition, different absorber types, namely, i-absorber, n-absorber and p-absorber, are compared to the proposed pn-absorber, showing a performance-boosting effect when using the latter. Moreover, the proposed structure is made without a hole transport layer (HTL) to avoid the organic issues of the HTL materials. The back metal work function, bulk trap density and ETL material are optimized for best performance of the HTL-free structure, giving Jsc = 26.48, Voc = 0.948 V, FF = 77.20 and PCE = 19.37% for AM1.5 solar spectra. Such results highlight the prospective of the proposed structure and emphasize the importance of using HTL-free solar cells without deteriorating the efficiency. The solar cell is investigated by using SCAPS simulator.

Authors

Marwa S Salem,Ahmed Shaker,Abdelhalim Zekry,Mohamed Abouelatta,Adwan Alanazi,Mohammad T Alshammari,Christian Gontand

Journal

Energies

Published Date

2021/9/12

Integrated multi-band RF transceiver design for multi-standard applications using 130​ nm CMOS technology

This paper presents high efficiency, high integration, and wideband low-IF radio frequency transceiver for multi-standard applications using 130​ nm CMOS technology. The proposed low-IF transceiver includes receiver, transmitter, and quadrature voltage-controlled power oscillator (QVCO). The proposed receiver consists of a low-noise driver stage designed using Capacitive Cross-Coupling (CCC) common-gate configuration, and I/Q demodulator. While, the proposed transmitter composes of an I/Q modulator and an RF power amplifier, where the I/Q modulator consists of two up-conversion mixers, a five ports transformer along with switched capacitors bank for reconfigurable RF output matching. The proposed receiver has a frequency band of 0–10​ GHz, while the operating frequency of the proposed transmitter equals 1.5–4​ GHz. The proposed RF transceiver design is suitable for multi-band LTE, IOT, WSN …

Authors

Marwa Mansour,Abdelhalim Zekry,Mohammed K Ali,Heba Shawkey

Journal

Microelectronics Journal

Published Date

2021/4/1

On architecture of self-sustainable wearable sensor node for IoT healthcare applications

In healthcare applications, the remote monitoring of moving patients depends on wearable nodes that should be mobile. Thus, wearable nodes should be power mains-disconnected most of the time to enable natural wandering of patients in the area. Thus, easy-to-use models are utilized in a seamless way. From this perspective, it becomes necessary to develop a generation of wearable nodes that are energy self-sustainable with minimal dependency on fixed power sources and also more safe in light of world health organization recommendations. In this paper, a solar energy harvesting technique is proposed to provide a mains power supply for an independent continuous operation of a patient monitoring node in sunny environments. A case study is built experimentally whereas the proposed designed node is architected as a combined node that enables parallel measurements of heart rate, blood …

Authors

Saeed Mohsen,Abdelhalim Zekry,Khaled Youssef,Mohamed Abouelatta

Journal

Wireless Personal Communications

Published Date

2021/7

A configurable waveform generator for radar applications

Modern radars are implemented using the SDR technique. This research focuses on designing and implementing integrated circuit boards that transmit desired radar signals and receive them to be used in targets detection and tracking, As a part of a complete configurable radar system. A configurable SDRadar that generates CW, phase-modulated pulsed and CW, linear frequency modulated CW, and amplitude modulated signals are designed and implemented using a generic and simple method. Any waveform can be constructed by specifying the values of four variables only that can be set online. When compared with the state-of-the-art, the resources are reduced by more than 50%. The circuit boards were designed using the Altium designer CAD tool, simulated using Hyper Lynx, and implemented that reduced the overall cost and size.

Authors

Kamal Hussein,Abdelhalim Zekry,Mohamed Abouelatta,Mohamed Mabrouk

Published Date

2021/12/15

Identification of power PIN diode design parameters: Circuit and device-based simulation approach

This paper aims to present a detailed systematic approach to identify the main design parameters of PIN power diodes. Firstly, the diode physical parameters are initialized using simple analytical equations. The second phase is the optimization of the diode parameters considering PSPICE circuit simulation where an electro-thermal physically based circuit model is utilized depending on a series of dynamic and static measurements. The final optimization step is carried out by using TCAD simulations. First, the diode extracted parameters are used to virtually fabricate the diode by using a process simulator. Then, using the output of the process simulator, a device simulator is used to get the desired output that is validated against experimental data. Three case studies for different power diodes are presented showing a good agreement between circuit/device simulation results and measurements. The presented …

Authors

Ahmed Shaker,Marwa S Salem,A Zekry,M El-Banna,GT Sayah,M Abouelatta

Journal

Ain Shams Engineering Journal

Published Date

2021/9/1

Approved algorithmic security enhancement of stream cipher for advanced mobile communications

Confidentiality and integrity processes are based on SNOW and ZUC algorithms. These standardized algorithms are designed by the 3rd Generation Partnership Project (3GPP) for advanced mobile communication systems. Each algorithm has two S-boxes in its nonlinear layer structure. This paper proposes three different approaches to enhance the security level of both algorithms. The first approach aims to select the best combination of two S-boxes in the nonlinear part of each algorithm. Results showed that the best randomness properties are achieved by combining the Feistel structure (S1-box) and Rijndael (S2-box) in the SNOW algorithm and New Rijndael (S1-box) and Rijndael (S2-box) in the ZUC algorithm. The second approach aims to increase the nonlinearity and complexity of these algorithms by selecting a strong S-box to cascade the best-existing two S-boxes for both algorithms. The third approach …

Authors

Zakaria Hassan Abdelwahab,Talaat A Elgarf,Abdelhalim Zekry

Journal

Information Security Journal: A Global Perspective

Published Date

2020/11/1

Simulink based modeling and performance analysis of NB-IoT uplink scheduler

Narrowband Internet of Things (NB-IoT) became a complement part of the fifth-generation (5G) network’s specifications due to its superiority to the other IoT networks from many different aspects. However, the relation between NB-IoT spectral efficiency and the type of IoT application is not studied enough. This paper evaluates the NB-IoT uplink scheduler’s performance based on the current standard for the four different NB-IoT data rates to study three performance metrics for each one. We apply our analysis to the traffic of periodic IoT applications. The Simulink environment’s State-flow toolbox is exploited, which supports state-machine modeling methodology to benefit from their features to model the NB-IoT access network’s uplink scheduler with a scalable model capability for future works. After verification and validation, our simulation results depict that the NB-IoT single-tone data rate achieves the highest …

Authors

Ahmed M Abbas,Abdelhalim Zekry,Khaled Y Youssef,Imbaby I Mahmoud

Published Date

2020/12/14

Enhancing the energy utilization of hybrid renewable energy systems

Without question combining two or more renewable energy sources (RES) in hybrid topology can increase the overall system reliability and efficiency especially if they have a complementary nature. However, most RES has an intermittent nature of energy production due to dependency on weather conditions. Therefore, there are big challenges for coordinating between multiple sources of energy to optimize energy utilization. Therefore, this paper introduces a genetic algorithm (GA) based energy management and optimization method for Hybrid Renewable energy Systems (HRES). The proposed technique aims to determine the optimum share of power generation of each source so that minimizing the energy cost and emission and prolonging the battery lifetime. The proposed technique has been tested with an HRES system consists of Solar PV, Wind Generator, and Battery storage. different operating conditions of temperature, Irradiance, Wind speed, Battery status have been considered and tested. Also, the proposed method regards environmental and economical optimization and system reliability and security. The paper introduces the mathematical model of system components and compared the obtained results of simulation work and experimental work for validation under different operating conditions including real temperature, irradiance, wind speed, load profile for 24 hours.

Authors

Yasser E Abu Eldahab,Naggar H Saad,Abdalhalim Zekry

Journal

International Journal of Renewable Energy Research (IJRER)

Published Date

2020/12

Analysis and design of a reconfigurable wideband I/Q modulator and Ultra-Wideband I/Q demodulator for multi-standard applications

This work presents an Ultra-Wideband (UWB) in-phase/quadrature (I/Q) demodulator, and a reconfigurable wideband (I/Q) modulator using 130​ nm CMOS process for multi-standard applications. The proposed designs are suitable for multi-band or wideband LTE RF transceiver. Both the RF stage in the demodulator, and the IF stage in the modulator are implemented using Capacitive Cross Coupling (CCC) common-gate configuration to enhance bandwidth and increase gain at a moderate power consumption. Furthermore, the reconfigurability of the modulator is achieved by matching the RF port by means of a high coupling wideband five ports transformer and a bank of switched capacitors for proper channel selection. The demodulator consumes 10.5​ mW from a 1.2​ V supply and it has conversion gain (CG) of 10​ dB with 3-dB bandwidth of 9​ GHz (1–10​ GHz). The demodulator input 1-dB compression …

Authors

Marwa Mansour,Abdelhalim Zekry,Mohammed K Ali,Heba Shawkey

Journal

Microelectronics Journal

Published Date

2020/8/1

NB-IoT optimization for smart meters networks of smart cities: Case study

The future demands for Smart Meters (SM) applications impose maximizing resources utilization. In this paper, we achieve two main objectives to comply with fifth-generation networks goals and serving the SM applications. First one is to enhance the Narrowband-Internet-of-Things spectral efficiency. The second is to alleviate the signalling burden during each transmission request for SMs. First, we model the uplink scheduler for the NB-IoT access network using the state-machine modelling methodology on the Simulink environment. The simulation results are verified and validated with trusted modelling technique. Second, we optimize the NB-IoT uplink scheduler, which exploits the periodicity nature of SMs applications. We achieve that by proposing an integrated scheduling protocol which rearranges the transmission times of different smart meters utilities, and it draws a map for the transmission schedule of them …

Authors

Ahmed M Abbas,Khaled Y Youssef,Imbaby I Mahmoud,Abdelhalim Zekry

Journal

Alexandria Engineering Journal

Published Date

2020/12/1

UTC (NIS) Steering Techniques with Few Number of Atomic Clocks

Till now, the Coordinated Universal Time of the National Institute of Standards (UTC(NIS)), which is the Egyptian Time Scale (TS), is generated by using a single Cesium (Cs) atomic clock. But, the reliability and frequency stability of UTC(NIS) in that case are limited by those of the single Cs clock. In the near future, UTC(NIS) will be generated by using the average atomic TS (TA(NIS)) from an ensemble of Cs clocks to enhance its reliability and frequency stability. In this paper, a simulation is carried out to check the effectiveness of generating TA(NIS) from the 3 Cs clocks of NIS clock ensemble. Results from TA(NIS) simulation will be presented and discussed before it is used for UTC(NIS) generation in the real-time. Also, in this paper, the two steering techniques that are currently used for UTC(NIS) generation instead of TA(NIS) to enhance its time accuracy with respect to the international TS (UTC) are introduced …

Authors

AI Mostafa,Abdelhalim Zekry

Published Date

2020/12/14

Numerical study of organic graded bulk heterojunction solar cell using SCAPS simulation

The graded bulk heterojunction (GBHJ) organic solar cell (OSC), with an active layer of donor-blend-acceptor structure, has recently paid much attention in developing the performance of OSCs. In this work, a numerical simulation has been performed for a GBHJ solar cell using SCAPS simulator to provide some design guidelines for this type of OSC. Firstly, the validation of the simulation is done by comparing the simulation with experimental results. Then, a comparative study is performed between the presented GBHJ with conventional bulk heterojunction (BHJ) and bi-layer solar cells. Simulation results indicate that GBHJ has the highest power conversion efficiency (PCE) of 10.15%, while BHJ has the highest collection efficiency (ζcoll) of 96.71%. The GBHJ performance is optimized by inspecting each layer individually and the interfacial trap states. It has been found that the main layer, having the most crucial …

Authors

W Abdelaziz,A Zekry,A Shaker,M Abouelatta

Journal

Solar Energy

Published Date

2020/11/15

A self-powered wearable sensor node for IoT healthcare applications

In this paper, a self-powered Internet of Things (IoT) wearable sensor node is proposed for healthcare monitoring. This node enables doctors of measuring the heart rate, blood oxygen saturation (SpO 2 ), and body temperature. This node is based on NodeMCU board that includes a microcontroller with a Wi-Fi chip. A solar energy harvester is developed as power supply to provide a solution for prolonging the lifetime of the node. This harvester is designed of two flexible photovoltaic (PV) panels, a charging controller, and a lithium-ion battery. The harvester is practically tested outdoors under direct sunlight and partly cloudy conditions. Experimentally, the IoT wearable sensor node consumes an average power of 20.23 mW over one hour and the lifetime of the node is 28 hours in a wake-up-sleep mode. Finally, the experimental results show that the monitored physiological data of the node are stored into an …

Authors

Saeed Mohsen,Abdelhalim Zekry,Mohamed Abouelatta,Khaled Youssef

Published Date

2020/12/14

Adaptive two‐stage spectrum sensing model using energy detection and wavelet denoising for cognitive radio systems

This paper presents an efficient adaptive two‐stage spectrum sensing model for the cognitive radio (CR) systems. The proposed model combines two well‐known techniques: energy detection (ED) and wavelet denoising (WD). The ED technique is employed to identify the existence of the primary user (PU) signal in the case of high signal‐to‐noise ratio (SNR) by comparing the received signal with a threshold. In the case of low SNR, the ED technique alone cannot be adopted for decision making about the status of the PU due to the noise impact on the received signals. Hence, the stage of WD is exploited prior to the ED for reducing the noise effect and detecting the PU signal in the presence of noise. The detection performance of the proposed model is compared with those of the ED alone and the previous related two‐stage spectrum sensing methods. Simulation results show that the proposed model improves …

Authors

Ahmed Fawzi,Walid El‐Shafai,Mohammed Abd‐Elnaby,Abdelhalim Zekry,Fathi E Abd El‐Samie

Journal

International Journal of Communication Systems

Published Date

2020/11/10

Design New Companding Scheme to Reduced PAPR for FBMC/OQAM in 5G Communication

In last few years, there is an increased requirement in the demand for high data rates over the wireless communication system. This demand motivated the researchers worldwide to move to higher generations of wireless communication systems characterized by high data rate, low drive motivation clamor, and high information move limit efficiency transmission. Therefore, Filter Bank Multicarrier with Offset Quadrature Amplitude Modulation (FBMC/OQAM) might be outstanding amongst other waveform utilized in the up and coming age of remote correspondence. But it is undergoing from a high peak to average power ratio. In this paper, we propose a new scheme called Weibull a nonlinear companding “WC” to reduce PAPR in the FBMC. This scheme is based on the transform of the originally Gaussian distributed FBMC signal magnitude into Weibull Distribution to effectively reduce the PAPR while preserving the …

Authors

Imad AA Shaheen,Abdelhalim Zekry

Published Date

2020/12/16

Design of Fuzzy logic controller for maximum power tracking of PV systems with its economical configurable Implementation on Arduino

this paper introduces a complete design of a fuzzy controller for MPPT in PV systems. The proposed controller is simulated in Simulink to prove the superior performance of the proposed fuzzy controller over the traditional perturb and observe algorithm. The simulation results show that the fuzzy controller has faster response and higher efficiency than perturb and observe controller. Hardware implementation of the proposed fuzzy controller is introduced. In this implementation low cost Arduino Uno controllers are used to implement the proposed controller. A complete hardware setup is introduced. A simple Arduino code software is written to control the Kit to perform the MPPT task. The hardware equipment consists of a power supply, Arduino kit, boost converter kit, resistor loads, current sensor, and voltage regulator board. A hardware test is performed in the lab to prove that the proposed fuzzy controller is working …

Authors

Ayman Youssef,Sawsan M Gharghory,Abdelhalim Zekry

Published Date

2020/12/3

A road map for transformation from conventional to photovoltaic energy generation and its challenges

In this introductory paper of this special issue, I will outline the basic principles that may govern the transformation from the conventional to the renewable photovoltaic energy supply. Based on the developed concepts, a transformation road map is proposed that describes the transformation could be realized in 40–45 years. The final issue treated in this paper is the proposed generic photovoltaic power system and its components. The scope of the published papers in this special issue is put within the frame work of this generic system.

Authors

Abdelhalim Zekry

Published Date

2020/11/1

Solar Cell Modification for Large Area Motion Detection: Proof of Concept

For a long time researchers try to develop tools or systems that could help in detecting the motion of the moving body and tracking it. It had a big importance in many fields such as sport performance, medical, virtual reality and many more fields. This paper proves that a solar cell can be modified to function as a Position Sensitive Detector (PSD), which could be used as the detector in a motion detection system. We modeled and simulated one dimensionally modified solar cell by TCAD simulation tools to calculate the detected photocurrent as a function of the position of an incident laser beam sourced by the moving object. The position detection error of the modified solar cell simulation is less than ± 1%. This shows the possibility of converting a solar cell to a PSD.

Authors

Heba Abdelmoneim Atia,Abdelhalem Zekry,Ahmed Shaker

Published Date

2020/12/14

Assessing wind energy conversion systems based on newly developed wind turbine emulator

Wind energy has the fastest and highest growth rate of any other Renewable energy sources (RES). Investigating the Wind Energy Conversion Systems (WECS) is very important for improving efficiency. However, It is required a monumental accessible land space for installing Wind turbines (WT). Consequently, this paper presents the design and implementation of a Wind turbine emulator (WTE) to substitute WTs. The proposed WTE includes a new Maximum Point Power Tracking (MPPT) technique based on integrating binary search technique and genetic algorithm. The proposed emulator has an SQLite database as a repository of wind turbine information. Also, it has a graphical user interface (GUI) to facilitate the operation. System components have been modeled and simulated using MATLAB Simulink. Furthermore, a prototype is implemented based on a series excited DC motor and permanent magnet synchronous (PMSG). All static and dynamic characteristics have been investigated to prove the capabilities of the developed emulator. Also, an integration test has been conducted on real-time conditions of wind speed profile and working load for 24 hours to check the reliability. The experimental results are compared with the simulation results for validation and showed the capability of the proposed WTE of emulating a wide range of Wind turbines.

Authors

YE Abu Eldahab,Naggar H Saad,Abdalhalim Zekry

Journal

International Journal of Smart Grid-ijSmartGrid

Published Date

2020/12

See List of Professors in Abdelhalim Zekry University(Ain Shams University)

Abdelhalim Zekry FAQs

What is Abdelhalim Zekry's h-index at Ain Shams University?

The h-index of Abdelhalim Zekry has been 26 since 2020 and 28 in total.

What are Abdelhalim Zekry's top articles?

The articles with the titles of

Orthogonal beamforming technique for massive MIMO systems

Numerical analysis of carbon-based perovskite tandem solar cells: Pathways towards high efficiency and stability

Acknowledgment to the Reviewers of Electronics in 2022

Investigation of high-efficiency and stable carbon-perovskite/silicon and carbon-perovskite/CIGS-GeTe tandem solar cells

A comprehensive review of tandem solar cells integrated on silicon substrate: Iii/v vs perovskite

User Selection Methods for Overcoming Growing Number of Served Users in Massive MIMO Systems

Enhanced Multiple Speakers’ Separation and Identification for VOIP Applications Using Deep Learning

A New Refined-TLBO Aided Bi-Generative Adversarial Network for Finger Vein Recognition

...

are the top articles of Abdelhalim Zekry at Ain Shams University.

What are Abdelhalim Zekry's research interests?

The research interests of Abdelhalim Zekry are: Electronics, Electronics for Communications, Photovoltaic

What is Abdelhalim Zekry's total number of citations?

Abdelhalim Zekry has 3,292 citations in total.

    academic-engine

    Useful Links