Abbas Semnani

Abbas Semnani

University of Toledo

H-index: 18

North America-United States

About Abbas Semnani

Abbas Semnani, With an exceptional h-index of 18 and a recent h-index of 13 (since 2020), a distinguished researcher at University of Toledo, specializes in the field of Plasma Science, Reconfigurable RF Electronics, Applied and Computational Electromagnetics, Inverse Scattering, Antennas.

His recent articles reflect a diverse array of research interests and contributions to the field:

An Efficient Atmospheric Pressure Resonant Microwave Plasma Line

Design and Analysis of a Plasma-Based Reconfigurable and Frequency-Selective Rasorber

A Plasma-Based Technique for Wideband Matching of Electrically Small Antennas

High-speed schlieren imaging of a highly-efficient atmospheric plasma jet

A Plasma Matching Approach to Realize Wideband and Efficient Small Antennas

Gas Breakdown for Nano-and Microscale Gaps: Linking Electron Emission and Avalanche Theories

A Conformal Plasma Frequency Selective Surface with Tunable and Switching Performance

Non-Radiating Resonances: Anapoles Enabling Highly-Efficient Plasma Jets within Dielectric Structures

Abbas Semnani Information

University

University of Toledo

Position

___

Citations(all)

942

Citations(since 2020)

460

Cited By

677

hIndex(all)

18

hIndex(since 2020)

13

i10Index(all)

25

i10Index(since 2020)

18

Email

University Profile Page

University of Toledo

Abbas Semnani Skills & Research Interests

Plasma Science

Reconfigurable RF Electronics

Applied and Computational Electromagnetics

Inverse Scattering

Antennas

Top articles of Abbas Semnani

An Efficient Atmospheric Pressure Resonant Microwave Plasma Line

Authors

Kushagra Singhal,Abbas Semnani

Journal

APS Annual Gaseous Electronics Meeting Abstracts

Published Date

2023

Atmospheric plasma jets have garnered considerable attention for their diverse applications across fields such as material processing, food, and manufacturing. However, existing plasma jet devices encounter limitations such as bulky design, inefficient power transfer, and jet profile. To address these challenges, microwave resonators, known for their ability to store and focus microwave power, can be employed to facilitate gas breakdown and generate plasma discharge. In particular, an evanescent-mode (EVA) cavity resonator plasma jet has been reported to achieve a power efficiency exceeding 80% with electron density in the range of 10 15 (cm-3). These resonators prove instrumental in enhancing the overall performance of plasma jets while enabling more efficient use of power and reducing the physical footprint of the device. This study introduces a resonant microwave plasma line based on EVA cavity …

Design and Analysis of a Plasma-Based Reconfigurable and Frequency-Selective Rasorber

Authors

Md Tanvir Ahmed,Krushna Kanth Varikuntla,Abbas Semnani

Journal

APS Annual Gaseous Electronics Meeting Abstracts

Published Date

2023

A frequency-selective absorber (FSA), also known as a rasorber, is a specialized structure designed to absorb a wide range of the electromagnetic (EM) spectrum while selectively allowing specific frequencies to either reflect or transmit through it. An FSR with wide absorption performance and a transmission band has many applications, including the multi-station Radar cross section (RCS) enhancement problem beyond the antenna working region. However, achieving a wideband absorption FSR with a narrow transmission band and low insertion loss is very challenging. This study focuses on investigating a frequency-selective absorber that exhibits a nearly transparent window between two absorption bands. The rasorber structure comprises a resistive sheet and a bandpass frequency-selective surface (FSS) with an air gap positioned in between. Gas discharge tubes (GDTs) have been employed as plasma …

A Plasma-Based Technique for Wideband Matching of Electrically Small Antennas

Authors

Abbas Semnani,Kushagra Singhal,Samsud T Moon

Published Date

2023/7/23

A plasma-based approach for wideband matching of electrically small antennas is introduced and validated in this work. The proposed technique relies on the negative permittivity of plasmas, which can be utilized to realize a negative capacitor within a capacitively coupled structure. The negative capacitance of plasma can compensate for the reactance of small antennas over a wide bandwidth while not introducing a significant loss. So, this technique can be a viable solution for efficient radiation over low frequency ranges, especially for high-power scenarios.

High-speed schlieren imaging of a highly-efficient atmospheric plasma jet

Authors

Pejman Nourani,Kazi Sadman Kabir,Abbas Semnani,Omid Amili

Journal

Bulletin of the American Physical Society

Published Date

2023/11/21

This study presents an extensive flow visualization of a highly-efficient microwave plasma jet. This atmospheric jet is a helium plasma plume exiting from a glass capillary tube with an inner diameter of 0.9 mm which passes through a gap region of an evanescent-mode cavity resonator. The specific design of the cavity concentrates the electric field mainly over the critical gap, and thus breakdowns the gas molecules even at very low values of input microwave power. The plasma jet is generated at 2.45 GHz with an input power in the range 0.5 to 10 W. A Z-type high-speed schlieren imaging system is used to investigate the hydrodynamic characteristics of the jet within the steady gas flow rate of 1 to 7 SLPM, both with and without the presence of plasma. We characterize the jet flow in terms of its core size and spread size, shear layer unsteadiness, and mixing of the helium jet with the surrounding air. The use of a …

A Plasma Matching Approach to Realize Wideband and Efficient Small Antennas

Authors

A Semnani,K Slnghal,ST Moon

Published Date

2023/5/21

The demand for wideband electrically small antennas (ESAs) is rapidly growing because of (1) the need fc compact multi-functional devices and (2) the limited space available in many applications, especially ove low radio-frequency range. However, ESAs are narrowband, non-efficient, and very difficult to be matchec especially over a wide frequency band. In an ESA, the frequency-dependent antenna impedance consists of a minimal resistance and a large reactance, which makes impedance matching necessary. Non-Foster matching networks with an equivalent negative capacitance are required for ESAs' wideband matching. Although active negative impedance converters (NICs) and metamaterials have been extensively investigated over the past decade for this aim, these networks are complicated and lossy with, typically, poor stability performance.

Gas Breakdown for Nano-and Microscale Gaps: Linking Electron Emission and Avalanche Theories

Authors

Allen Garner,Amanda Loveless,Haoxuan Wang,Shivani Mahjan,Venkattraman Ayyaswamy,Abbas Semnani

Journal

APS Annual Gaseous Electronics Meeting Abstracts

Published Date

2023

Predicting discharge formation is critical for many applications. In some cases, such as combustion or medicine, the goal is to generate discharges to leverage reactive species formation. For other applications, such as pulsed power systems or microelectronics, plasma formation indicates device failure. Traditionally, Townsend avalanche drives discharge formation and is predicted mathematically by Paschen's law (PL), which shows that the breakdown voltage scales with the product of gas pressure and gap distance. Reducing device size increases the electric field at the cathode at breakdown, stripping electrons by field emission. These electrons ionize the gas near the cathode, which increases secondary emission and creates an additional electric field due to the positive space-charge. These phenomena reduce the voltage necessary to induce breakdown; therefore, the breakdown voltage decreases at smaller …

A Conformal Plasma Frequency Selective Surface with Tunable and Switching Performance

Authors

Krushna Kanth Varikuntla,Abbas Semnani

Journal

APS Annual Gaseous Electronics Meeting Abstracts

Published Date

2023

In the quest to safeguard sensitive electronic equipment, the demand for frequency-selective surfaces (FSS) that can be conformally adhered to complex surfaces while maintaining stable frequency-selective properties and transmission performance remains high. While various flexible shielding options have been introduced, achieving adequate protection against HPM requires a tunable and reconfigurable FSS capable of selectively blocking a specific frequency range during a high-power threat. Such a tunable and reconfigurable FSS serves a crucial purpose by shielding sensitive electronic equipment from high-power threats while permitting the unaffected transmission of desired frequencies. This dynamic capability to shut off a specific frequency window during a high-power threat is vital for ensuring optimal protection without compromising the functioning of the sensitive equipment. By leveraging tunability …

Non-Radiating Resonances: Anapoles Enabling Highly-Efficient Plasma Jets within Dielectric Structures

Authors

Muhammad Rizwan Akram,Abbas Semnani

Journal

arXiv preprint arXiv:2311.00572

Published Date

2023/11/1

Plasma plays a pivotal role in numerous applications spanning the fields of medicine, industry, agriculture, and space exploration. When plasma interacts with air, it initiates unique chemical reactions, resulting in the creation of rare and highly sought-after reactive species. Typically, the generation of plasma jets for interaction with air relies on resonant cavities to enhance plasma efficiency. In this study, we have harnessed the innovative concept of non-radiating sources, known as anapoles, which utilize the lowest order multipoles specifically, electric-electric dipole interactions within a hybrid metallo-dielectric structure. This approach enhances the near electric field, facilitating gas breakdown for the realization of a plasma jet. The achievement of a dielectric plasma jet is remarkable in its own right, particularly when considering the open structure employed, which enables frequency tuning. Furthermore, the prototype we have demonstrated surpasses existing plasma jet technologies in several key aspects, including compactness, compatibility with planar fabrication techniques, power efficiency, cost-effectiveness, tunability, and a twofold increase in electron density compared to the highest levels achieved to date. With these substantial enhancements, our proposed device is poised to revolutionize the landscape of plasma source technology and open up exciting avenues for exploring novel applications.

An Absorptive Plasma Topology for Frequency Selective Microwave Protection

Authors

SN Ramesh,KK Varikuntla,A Semnani

Published Date

2023/5/21

High-power microwaves (HPM) are intense energy threats that can damage electrical systems and disrupt communications. Although many plasma limiters and protection shields have been introduced so far [1], [2], adequate protection against HPM is a reconfigurable frequency-selective limiter (FSL) that can operate over safe frequency bands and shut off a frequency window that encounters a high-power threat. The architectures proposed over the recent years to realize FSLs are mainly based on utilizing diodes, thin films, and ferrite materials-however, those suffering from low power handling, high loss, suboptimal tunability, and poor selectivity.

A Power-Efficient Microwave Microplasma Jet Utilizing an SIW Evanescent-Mode Cavity Resonator

Authors

Kazi Sadman Kabir,Abbas Semnani

Published Date

2023/6/11

This paper introduces a novel 2.45 GHz microplasma jet implemented over substrate-integrated waveguide (SIW) technology. The proposed plasma jet is realized by exploiting an evanescent-mode (EVA) cavity resonator built using two separate PCB boards stacked over each other to introduce a critical gap between the two substrates around the top-center position. This allows for realizing a concentrated |E|-field in the gap for plasma formation. A capillary tube is passed right through the middle of the structure to pump helium through the critical gap area. After gas breakdown owing to the strong |E|-field in the gap with > 2.7 W input power, the gas flow pushes the plasma plume out, which is up to 3-mm long with 7 slpm gas flow rate. The proposed technology is an excellent option for many applications owing to its high efficiency, planar profile, and compatibility with PCB fabrication.

Impedance Matching in Small Antennas through Capacitively-Coupled Plasma Technique

Authors

Abbas Semnani,Kushagra Singhal,Samsud Moon

Journal

APS Annual Gaseous Electronics Meeting Abstracts

Published Date

2023

The demand for electrically small antennas (ESAs) is primarily driven by the need for compact, multi-functional devices operating in the low radio-frequency range. However, ESAs inherently suffer from narrowband characteristics and low efficiency. Theoretically, it has been demonstrated that wideband matching of ESAs is achievable by employing non-Foster matching networks that represent negative capacitance. In pursuit of this theory, various approaches, such as active negative impedance converters (NICs) and metamaterials, have been investigated over the past decade. However, these networks often exhibit complexity, significant losses, and limited stability performance, which hinder their practical implementation. This study presents a novel approach utilizing capacitively coupled plasma for achieving wideband matching in small antennas. The proposed technique leverages the negative permittivity …

Resonant Impedance Tuners: Theory, Design, Power Handling, and Repeatability

Authors

Garrett Shaffer,W Joel D Johnson,Thomas R Jones,Abbas Semnani,Dimitrios Peroulis

Journal

IEEE Transactions on Microwave Theory and Techniques

Published Date

2023/10/13

The theory of coupled-resonator-based impedance tuners is presented for the first time, establishing coverage limitations for two-and three-resonator designs. Besides the advantages of resonant impedance tuners, practical considerations including resonator loss and limited tuning range are included in the analysis. From this theoretical background, a rigorous design procedure is presented for creating optimal resonant impedance tuners, designed for maximum Smith chart coverage, for both the two-and three-pole structures. A proof-of-concept three-pole impedance tuner is created following this procedure. This state-of-the-art tuner achieves at least 90% Smith chart coverage from 4 to 8 GHz while maintaining minimum transducer losses of 0.4 dB. The designed tuner is implemented on printed circuit board (PCB) technology and uses electronically controllable linear actuators for tuning. With these design choices …

An Efficient Microwave Microplasma Jet Realized with Printed Circuit Board Technology

Authors

KS Kabir,A Semnani

Published Date

2023/5/21

Plasma jets are used in various biological applications such as cancer treatment, blood clotting prevention, and wound healing. However, current commercially available units are often bulky, power-hungry, and expensive. Utilizing microwave resonators to realize microwave plasma jets is an attractive solution owing to their ability to focus, store, and efficiently reroute the EM energy, which allows for gas breakdown and hence plasma formation with much less power. Various microwave resonant structures have been reported for low-power plasma creation. However, many are not optimal for medical applications because they cannot operate in atmospheric air.

A Compact and High-Power Frequency-Selective Plasma Limiter with an Ultra-High Isolation

Authors

Sandeep Narasapura Ramesh,Abbas Semnani

Published Date

2023/6/11

A novel frequency-selective limiter is introduced in this paper, which is based on integrating a plasma cell into an absorptive resonant topology. The limiter response transitions from all-pass to bandstop when the input power exceeds the threshold for gas breakdown inside the plasma cell. This is a consequence of the change from constructive interference in the all-pass mode to destructive interference in the bandstop mode due to the change in dielectric properties of the plasma cell. Implemented using two quarter-wave microstrip resonators, a gas discharge tube (GDT) as a plasma cell, and a delay line, a less than 1.6 dB loss, over 60 dB selective isolation with a measured FBW of 2.8% were achieved. This is despite the low-quality-factor resonators used in this prototype device and the intrinsic plasma loss. The limiter handles significantly high input power of over 100 W, better than the state-of-the-art frequency …

Evaluation of Reactive Species in a Frequency-Tunable Resonant Microwave Plasma Jet

Authors

Kazi Sadman Kabir,Abbas Semnani

Journal

APS Annual Gaseous Electronics Meeting Abstracts

Published Date

2023

Plasma jets generate a stream of chemical species, including ions, electrons, and radicals, which are crucial in various biomedical and industrial applications. Hence, alongside a power-efficient performance, control over reactive species production is essential. Among the existing technologies, the evanescent-mode cavity resonator structure has emerged as a promising candidate for achieving power-efficient plasma sources. This technology enhances and confines electromagnetic fields, enabling the ignition and sustenance of plasma jets even at power levels in the milliwatt range. The type and concentration of chemical species generated by such sources can be controlled through several operating parameters such as input power, background gas type and pressure, and gas flow rate. Introducing frequency tunability offers an additional means to manipulate these reactive species. Motivated by this potential, we …

Tuning of Radio-Frequency (RF) Plasmas by a Perpendicular Magnetic Field

Authors

Samsud Moon,Abbas Semnani

Journal

APS Annual Gaseous Electronics Meeting Abstracts

Published Date

2023

Recently, there has been a surge of interest in exploring the tunability of plasma for high-frequency applications. This interest stems from the wide range of tunability of plasma permittivity and electrical conductivity offered by plasma and the unique characteristic of being the only natural material capable of providing negative permittivity. Traditionally, plasma has been tuned by adjusting parameters such as pressure, input power, and excitation frequency. However, an alternative and promising approach involves manipulating plasma properties using an external magnetic field. Currently, there is a lack of readily available information regarding the electrical properties of a capacitively coupled plasma sustained by radiofrequency (RF) power under the influence of a perpendicular magnetic field. Past research has proposed manipulating plasma properties, such as electron number density, to facilitate communication …

A Microwave Anapole Source Based on Electric Dipole Interactions Over a Low-Index Dielectric

Authors

Muhammad Rizwan Akram,Abbas Semnani

Journal

arXiv preprint arXiv:2308.15554

Published Date

2023/8/29

The pursuit of non-radiating sources and radiation-less motion for accelerated charged particles has captivated physicists for generations. Non-radiating sources represent intricate current charge configurations that do not emit radiation beyond their source domain. In this study, we investigate a single non-radiating source, comprising a low-index dielectric disk excited by a split ring resonator. Employing analytical and numerical methods, we demonstrate that this configuration supports an anapole state, exhibiting minimal or no radiation, effectively representing a non-radiating source. The radiation suppression is accomplished through the destructive interference of electric dipoles excited on the metallic and dielectric components of the proposed prototype. Transforming the design into a cost-effective device capable of suppressing radiation, we achieve impressive numerical and experimental agreement, affirming the formation of the anapole state using the lowest order multi-poles. Moreover, the devised anapole device is remarkably compact, constructed from a low-index dielectric, and employs readily available components. As a versatile platform, the proposed device can spearhead anapole research for diverse applications, including sensing, wireless charging, RFID tags, and other non-linear applications.

Power-Efficient Microwave Plasma Jet Based on Evanescent-Mode Cavity Technology

Published Date

2023/6/8

Plasma jet assemblies utilizing evanescent mode cavity resonators, and methods of making the same and using the same, are described.

A Dielectric Resonator-Based Microwave Plasma Jet

Authors

Muhammad Rizwan Akram,Abbas Semnani

Journal

APS Annual Gaseous Electronics Meeting Abstracts

Published Date

2023

This study introduces a cylindrical dielectric resonator placed on a metallic ground plane, which is excited by a slot etched through the ground plane. A simple feeding mechanism based on microstrip technology is utilized to couple the input microwave energy to the resonator. Achieving impedance matching is accomplished by adjusting the position of the microstrip line relative to the slot. By effectively suppressing radiation, the energy surrounding the device experiences a significant enhancement, which, combined with a controlled gas flow through the device, leads to gas breakdown. Consequently, a highly efficient atmospheric pressure microwave plasma jet is formed. Compared to previous studies, the proposed device exhibits several significant advantages: It is highly compact, fully planar, and has a low profile, making it suitable for integration and compatible with printed circuit board fabrication techniques …

A Plasma-Based Frequency-Selective Limiting Reflectarray

Authors

Krushna Kanth Varikuntla,Abbas Semnani

Journal

APS Annual Gaseous Electronics Meeting Abstracts

Published Date

2023

High-power microwaves can disrupt communication frequencies and cause extensive damage to electronic equipment. Therefore, it is crucial to shield sensitive equipment from incoming high-power waves. Frequency-selective surfaces (FSS) are planar periodic arrays that exhibit selective filtering responses. Various architectures have been proposed to implement these surfaces for protection applications in recent years. However, many of these structures rely on active elements such as PIN and Schottky diodes, which suffer from limitations such as low power handling, wide bandwidth, and poor selectivity. This study introduces a novel frequency-selective limiting reflectarray, utilizing an innovative approach of integrating plasma cells into an absorptive resonant topology. The proposed design offers a distinctive response characteristic where the limiter transitions from a reflection state to selective narrowband …

See List of Professors in Abbas Semnani University(University of Toledo)

Abbas Semnani FAQs

What is Abbas Semnani's h-index at University of Toledo?

The h-index of Abbas Semnani has been 13 since 2020 and 18 in total.

What are Abbas Semnani's top articles?

The articles with the titles of

An Efficient Atmospheric Pressure Resonant Microwave Plasma Line

Design and Analysis of a Plasma-Based Reconfigurable and Frequency-Selective Rasorber

A Plasma-Based Technique for Wideband Matching of Electrically Small Antennas

High-speed schlieren imaging of a highly-efficient atmospheric plasma jet

A Plasma Matching Approach to Realize Wideband and Efficient Small Antennas

Gas Breakdown for Nano-and Microscale Gaps: Linking Electron Emission and Avalanche Theories

A Conformal Plasma Frequency Selective Surface with Tunable and Switching Performance

Non-Radiating Resonances: Anapoles Enabling Highly-Efficient Plasma Jets within Dielectric Structures

...

are the top articles of Abbas Semnani at University of Toledo.

What are Abbas Semnani's research interests?

The research interests of Abbas Semnani are: Plasma Science, Reconfigurable RF Electronics, Applied and Computational Electromagnetics, Inverse Scattering, Antennas

What is Abbas Semnani's total number of citations?

Abbas Semnani has 942 citations in total.

What are the co-authors of Abbas Semnani?

The co-authors of Abbas Semnani are Dimitrios Peroulis, Sergey Macheret, Pedram Mousavi, Alina Alexeenko, Xun Gong, Ioannis T. Rekanos.

    Co-Authors

    H-index: 54
    Dimitrios Peroulis

    Dimitrios Peroulis

    Purdue University

    H-index: 43
    Sergey Macheret

    Sergey Macheret

    Purdue University

    H-index: 36
    Pedram Mousavi

    Pedram Mousavi

    University of Alberta

    H-index: 35
    Alina Alexeenko

    Alina Alexeenko

    Purdue University

    H-index: 31
    Xun Gong

    Xun Gong

    University of Central Florida

    H-index: 26
    Ioannis T. Rekanos

    Ioannis T. Rekanos

    Aristotle University of Thessaloniki

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