Electrical characteristics of gated-anode diode for rectenna using normally-off gan hemt

IEICE Technical Report; IEICE Tech. Rep.

Published On 2020/9/30

(in English) As a device for wireless power transmission, we are developing a new rectenna that uses a gated anode diode (GAD) that short-circuits the gate electrode and ohmic electrode of a normally-off type GaN HEMT. In this study, a wide recess gate type GaN GAD was prepared and the recess length dependence of its electrical characteristics was investigated. Typical DC characteristics of the HEMT are a threshold voltage Vth of+ 0.3 V and a maximum drain current Imax= 300 mA/mm. The GAD using this HEMT showed the characteristics of forward current If= 350 mA/mm and reverse breakdown voltage BVr= 40 V. When the performance of the bridge type rectifier at 5.8 GHz was predicted using the SPICE model extracted from this device, good characteristics with a rectifier efficiency of 81% and a DC output of 10 W were obtained with a GAD with a gate width of 0.8 mm.

Journal

IEICE Technical Report; IEICE Tech. Rep.

Published On

2020/9/30

Volume

120

Issue

182

Page

1-5

Authors

Suda Jun

Suda Jun

Nagoya University

Position

/ Kyoto University

H-Index(all)

47

H-Index(since 2020)

32

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

Physics

Electronics

Semiconductors

University Profile Page

Yuji Ando

Yuji Ando

Nagoya University

Position

H-Index(all)

29

H-Index(since 2020)

13

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

Semiconductor devices

University Profile Page

Naoki Sakai

Naoki Sakai

Kanazawa Institute of Technology

Position

H-Index(all)

8

H-Index(since 2020)

6

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

Microwave circuit

Wireless power transfer

Rectifier

University Profile Page

Other Articles from authors

Suda Jun

Suda Jun

Nagoya University

IEEE Transactions on Electron Devices

Demonstration of AlGaN-on-AlN pn Diodes With Dopant-Free Distributed Polarization Doping

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Suda Jun

Suda Jun

Nagoya University

IEEE Transactions on Electron Devices

Improved Turn-On Voltage Controllability in AlGaN/GaN Gated-Anode Diodes Using Etch Endpoint Detection Layer

AlGaN/GaN gated-anode diodes (GADs) have been proposed as microwave rectifying devices for microwave wireless power transmission (WPT) systems. However, achieving the desired turn-on voltage ( ) has posed a critical challenge due to the requirement for precise etching control. This article introduces a novel GAD structure aimed at enhancing productivity. In this new configuration, a GaN etch endpoint detection layer (GaN marker layer) is incorporated into the AlGaN layer, positioned approximately 4.5 nm away from the channel interface. During gate recess etching, the residual thickness of AlGaN is monitored using an optical interferometer. Etching is halted successfully upon detection of the GaN marker layer, signaled by an abrupt change in interference. Fabricated GADs consistently achieved the target of 0.20 V, exhibiting improved uniformity compared to prior GADs lacking a GaN marker …

Yuji Ando

Yuji Ando

Nagoya University

Journal of Electron Devices

Electrical characterization of AlGaN/GaN-HEMTs on semi-insulating GaN substrates doped with Fe, C, or Mn and grown by hydride vapor phase epitaxy

Deep traps in AlGaN/GaN high electron mobility transistors on silicon substrate were characterized by the means of current-voltage and Deep Level Transient Spectroscopy (DLTS). DLTS measurements have revealed only hole-trap with an activation energy of 0.82 eV. The nature and the localization of this trap are discussed here.

Suda Jun

Suda Jun

Nagoya University

Journal of Electron Devices

Electrical characterization of AlGaN/GaN-HEMTs on semi-insulating GaN substrates doped with Fe, C, or Mn and grown by hydride vapor phase epitaxy

Deep traps in AlGaN/GaN high electron mobility transistors on silicon substrate were characterized by the means of current-voltage and Deep Level Transient Spectroscopy (DLTS). DLTS measurements have revealed only hole-trap with an activation energy of 0.82 eV. The nature and the localization of this trap are discussed here.

Suda Jun

Suda Jun

Nagoya University

Applied Physics Express

Demonstration of recycling process for GaN substrates using laser slicing technique towards cost reduction of GaN vertical power MOSFETs

To address the issue of the high cost of GaN substrates, a recycling process for GaN substrates using a laser slicing technique was investigated. The channel properties of lateral MOSFETs and the reverse characteristics of vertical PN diodes, which represent the main components of vertical power devices, exhibited no degradation either before and after laser slicing or due to the overall GaN substrate recycling process. This result indicates that the proposed recycling process is an effective method for reducing the cost of GaN substrates and has the potential to encourage the popularization of GaN vertical power devices.

Suda Jun

Suda Jun

Nagoya University

Japanese Journal of Applied Physics

Suppression of threshold voltage shift due to positive bias stress in GaN planar MOSFETs by post-deposition annealing

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Suda Jun

Suda Jun

Nagoya University

Characterization of Shockley-Read-Hall recombination centers created by proton irradiation into GaN p+/n-and p-/n+ junctions

Proton irradiation-induced point defects acting as Shockley-Read-Hall (SRH) recombination centers in homoepitaxial GaN p-n junctions were characterized based on analyses of recombination current. Positron annihilation spectroscopy (PAS) data indicated that the vacancies in the GaN specimens comprised Ga vacancies and divacancies. The SRH lifetimes were decreased with the increase of the 4.2 MeV proton dose. For the same dose, the carrier concentrations and the SRH lifetimes for p-/n+ junctions were significantly reduced compared with those for p+/n- junction. The results suggest the asymmetry of defect formation in GaN based on the fact that intrinsic point defects in p-type GaN readily compensate for holes. The authors thank Mr. Takahide Yagi and Mr. Joji Ito of SHIATEX Co., Ltd., for performing proton irradiation and irradiation simulations. The authors thank Dr. Akira Uedono of Tsukuba Materials …

Yuji Ando

Yuji Ando

Nagoya University

Laser slicing of GaN

Practical application of devices using GaN substrates has been slow to progress. One of the big reasons is that the price of the GaN substrate is very expensive. To solve this issue, we propose a new GaN substrate slicing method using laser as a method that can contribute much more to the cost reduction of GaN substrate. With this technology, it is possible to reduce kerf loss to almost zero. Under the current slicing conditions, the damage depth after laser slicing is about 14um, and device epilayers could be grown on the sliced substrate by removing this thickness. In addition, this slicing does not require water or coolant and does not contaminate the workpiece. Therefore, laser slicing can also be used to thin the devices. By using laser slicing instead of backgrinding at the end of the device fabrication process, device layers can be thinned while leaving the substrate reusable.

Suda Jun

Suda Jun

Nagoya University

Applied Physics Express

Nitrogen-displacement-related recombination centers generated by electron beam irradiation in n-type and p-type homoepitaxial GaN layers

Recombination centers originating from point defects generated by the displacement of N atoms in n-type and p-type GaN were investigated by analyzing Shockley–Read–Hall (SRH) recombination currents in homoepitaxial GaN p–n junctions. These defects were intentionally generated by electron beam (EB) irradiation at 137 keV. The net doping concentrations in p+–n junction diodes were not changed following irradiation although the levels in p–n+ junction diodes decreased as the EB fluence was increased. The SRH recombination current also increased with increases in the fluence. This work additionally evaluated the relationship between recombination lifetimes and trap concentrations obtained by deep level transient spectroscopy.

Suda Jun

Suda Jun

Nagoya University

IEEE Transactions on Electron Devices

Guest Editorial: Special Issue on Wide and Ultrawide Band Gap Semiconductor Devices for RF and Power Applications

On behalf of myself and the other guest editors for the Special Issue on “Wide and Ultrawide Band Gap Semiconductor Devices for RF and Power Applications” featured in this month’s IEEE Transactions on Electron Devices, we are pleased to offer readers a selection of papers that span the contemporary landscape of wide and ultrawide bandgap semiconductor devices.

Suda Jun

Suda Jun

Nagoya University

Applied Physics Letters

Record high electron mobilities in high-purity GaN by eliminating C-induced mobility collapse

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Suda Jun

Suda Jun

Nagoya University

Applied Physics Express

Realization of low specific-contact-resistance on N-polar GaN surface using heavily-Ge-doped n-type GaN films deposited by low-temperature reactive sputtering technique

We developed a low-temperature ohmic contact formation process for N-polar GaN surfaces. Specific-contact-resistances of 9.4 × 10−5 and 2.0 × 10−5 Ω·cm2 were obtained using Ti/Al metal stacks on heavily-germanium-doped GaN films, which were deposited at 500 °C and 600 °C using a radical-assisted reactive sputtering method, respectively. The electrode sintering temperature was as low as 475 °C. Carrier concentrations for the 500 °C and 600 °C samples were 2.6 × 1020 and 1.8 × 1020 cm−3, respectively. These results suggest that this method is highly effective in reducing the contact resistance of GaN devices with low thermal budgets.

Yuji Ando

Yuji Ando

Nagoya University

IEEE Transactions on Electron Devices

Improved Turn-On Voltage Controllability in AlGaN/GaN Gated-Anode Diodes Using Etch Endpoint Detection Layer

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Naoki Sakai

Naoki Sakai

Kanazawa Institute of Technology

An Integrated Planar Guanella Balun with the Quasi-Coaxial Structure on GaAs Substrate

This paper proposes a planar Guanella balun with the quasi-coaxial structure. This is the first report of the Guanella balun fabricated on a GaAs substrate. The quasi-coaxial structure is configured with metal layers on three thin dielectric layers of a few micrometers thickness. These layers are laminated on the GaAs substrate. The metal on the second layer (the second metal) is an inner conductor, which is surrounded by the first and third metals correspond to an outer conductor. The first and third metals are split lines to widen the inner conductor. The fabricated Guanella balun has a spiral shape, and its size is by . The fabricated Guanella balun shows less than of amplitude imbalance and 7.3 degrees of phase imbalance from 5 GHz to 15GHz. The fabricated Guanella balun is realized with half elements of a Marchand balun and achieves good performance with small size.

Naoki Sakai

Naoki Sakai

Kanazawa Institute of Technology

IEEE Antennas and Wireless Propagation Letters

Graded Index Fiber-Inspired 3-D Printed Surface Focusing Porous Dielectric Structure With GaAs MMIC Rectenna Towards Millimeter Wave Wireless Power Transfer Application

Borrowing the idea of the graded-index (GRIN) fiber, we propose an all-dielectric porous structure with a unique surface focusing feature to improve the performance of the rectenna for millimeter-wave (mm-Wave) wireless power transfer (WPT) applications in this letter. The on- and off-axis focusing properties of the proposed structure are analyzed by the full-wave electromagnetic simulation. Moreover, benefitting from the low-cost 3-D printing technique, the designed GRIN structure prototype with different pore densities of the polylactic acid material is fabricated. The near-field phase transform experiment at 28 GHz was carried out to verify the excellent focusing performance of the fabricated structure prototype. Besides, the characteristics of multifocal spots on the surface of the proposed structure are further confirmed by the mm-Wave WPT experiments with a GaAs monolithic microwave integrated circuit rectenna …

Suda Jun

Suda Jun

Nagoya University

Impacts of vacancy clusters on the recombination dynamics in Mg-implanted GaN on GaN structures

The results of complimentary time-resolved photoluminescence and positron annihilation measurements on Mg-implanted GaN on GaN fabricated using various I/I sequences will be shown to identify the species and quantify the concentrations and minority carrier capture coefficients of major midgap recombination centers (MGRCs) created by the I/I processes. Because vacancy clusters comprised of Ga vacancies (VGa) and N vacancies (VN) such as (VGaVN)3 were assigned as major vacancy-type defects and the room-temperature photoluminescence lifetime for the NBE emission increased with decreasing their concentration, (VGaVN)3 are assigned as major nonradiative recombination centers with electron capture coefficient of 5×10-6 cm3s-1, which is an order of magnitude larger than the hole capture coefficient of VGaVN in n-GaN (6×10-7 cm3s-1). Financial supports: CSTI-SIP, MEXT (JPJ005357 …

Suda Jun

Suda Jun

Nagoya University

Applied Physics Letters

Correlation between non-ionizing energy loss and production rate of electron trap at EC−(0.12–0.20) eV formed in gallium nitride by various types of radiation

Production rate (PR= trap concentration/incident fluence) of traps formed by energetic particles is important for predicting device degradation caused by radiation when developing radiation-resistant devices. We demonstrate a clear correlation between non-ionizing energy loss (NIEL) and PR of an electron trap at about 0.12–0.20 eV below the conduction band edge [E C−(0.12–0.20) eV] for various types of energetic particles in gallium nitride (GaN). NIEL values in GaN for electrons, protons, and α-rays were calculated using a screened-relativistic treatment, and NIEL values for gamma-rays were calculated by simulating slowed-down spectra due to shielding material. To obtain the PRs of the electron trap, 60 Co gamma-rays with an average photon energy of 1.25 MeV and electron beams with energies from 137 keV to 2 MeV were irradiated onto n-type GaN Schottky barrier diodes. We measured the …

Naoki Sakai

Naoki Sakai

Kanazawa Institute of Technology

IEICE Conferences Archives

高効率・大電力レクテナ

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Naoki Sakai

Naoki Sakai

Kanazawa Institute of Technology

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GaAs E-pHEMT gated anode diode を用いた 5.75 GHz 帯 1W レクテナ

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Naoki Sakai

Naoki Sakai

Kanazawa Institute of Technology

IEICE Conferences Archives

塗布型カーボンナノチューブ薄膜トランジスタによる Gated anode diode を用いる 920MHz 帯レクテナ

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IEICE Technical Report; IEICE Tech. Rep.

A Preliminary Study on Parameter Optimization Using a Backpropagation Algorithm for a Neonatal Thermal Model

(in English) Neonates need temperature management in incubators due to their underdeveloped thermoregulatory functions. Traditional methods using skin-attached probes are challenging due to the neonates' delicate skin. Therefore, efforts are being made to realize non-contact temperature measurement using thermography. However, thermography can be hindered during medical procedures by obstructions like medical staff's hands. To address this, we utilize a human thermal model to simulate body temperature changes, integrating real-time sensor data, including thermography and incubator conditions, to estimate surface and core body temperatures. Our method employs backpropagation for rapid parameter optimization in the human thermal model. The effectiveness was confirmed using actual neonatal data, achieving core body temperature estimation with an average absolute error of 0.032$ degree …

Sinan Chen

Sinan Chen

Kobe University

IEICE Technical Report; IEICE Tech. Rep.

A Study of Promotion Method for Energy-Saving Behavior in Homes with Personalized Adaptive Interaction

(in English) In recent years, climate change, including global warming, has become a serious issue, and Japan is aiming to realize a zero carbon society. Zero carbon means reducing the net emissions of greenhouse gases to zero by balancing the amount emitted and absorbed, which is crucial for reducing CO2 emissions. This study focuses on energy reduction through in-home energy-saving actions, addressing issues such as the lack of acquisition of appliance-specific electricity consumption data, lack of personal adaptation, and oversight of notifications. To address these, a method that integrates a power consumption management service using IoT devices and baselines with a virtual agent (VA) was proposed and implemented. The evaluation experiment confirmed that the introduction of VA led to a reduction in power consumption, and an improvement in energy-saving consciousness and behavioral …

RUBITA SUDIRMAN

RUBITA SUDIRMAN

Universiti Teknologi Malaysia

IEICE Technical Report; IEICE Tech. Rep.

An Evaluation of CNN Using Deep Residual Learning for Modulation, 5G, LTE, and WLAN System Classification

(in English) In this study, we investigate and present a deep residual learning for modulation classification. The simulation results show the degradation problem that was exposed due to an increase in network depth and the saturation of accuracy in the modified conventional CNN; however, the proposed CNN has no such degradation. Therefore, the processing burden of the conventional CNN is much larger than the proposed CNN. In the simulation results, the proposed CNN framework achieves almost the same modulation classification accuracy as the normal CNN framework when reducing the processing burden in the proposed one. The better simulation results are shown by adjustment of the parameters using the proposed method in the case of OFDM and single carrier modulation types.

Shinji Watanabe

Shinji Watanabe

Carnegie Mellon University

IEICE Technical Report; IEICE Tech. Rep.

Evaluating speech generation based on objective measures for text generation

(in English) In the evaluation of speech generation, while subjective judgments have long been the gold standard, objective metrics such as Mel Cepstral Distortion (MCD) and Mean Opinion Score (MOS) prediction models have also been used. These objective metrics are valued for their lower time and financial costs and the ability to compare different results, driving the demand for metrics that correlate well with human subjective judgments. This paper proposes an automatic evaluation method for speech generation based on text generation metrics. Our proposed SpeechBERTScore computes BERTScores on self-supervised speech feature sequences derived from both generated and reference speech. In addition, SpeechBLEU and SpeechTokenDistance define metrics using self-supervised discrete speech tokens. Experimental evaluations of synthesized speech show that our SpeechBERTScore correlates …

Yohei Murakami

Yohei Murakami

Ritsumeikan University

IEICE Technical Report; IEICE Tech. Rep.

Cooperative Agents for Federated Learning of Neural Machine Translation

(in English) Accurate neural machine translation requires large amounts of high-quality bilingual data, however due to the copyright and confidentiality issues, it is difficult to share the bilingual data between different organizations. With federal learning, multiple clients can collaboratively build a neural machine translation model and share only the translation model while keeping their own data confidential. However, if the domain of bilingual data differs among clients, the translation accuracy is not necessarily improved by integrating all translation models. Therefore, we propose a cooperative agent that dynamically selects a cooperative partner and integrates translation models in each aggregation process in cooperative learning. Compared to conventional cooperative learning methods, our method can improve the translation accuracy of each client by 22.7% on average.

TUTOMU MURASE

TUTOMU MURASE

Nagoya University

IEICE Technical Report; IEICE Tech. Rep.

Segmented file delivery method by mobile APs using a combination of overhearing and transmission rate control

(in English) In the event of a large-scale disaster, there is a possibility that the communication infrastructure may not work properly. Therefore, a method of distributing evacuation information that does not depend on the communication infrastructure is required. Ad hoc networks and DTNs are available as communication methods that do not depend on the infrastructure in the event of a disaster. In addition, other research has proposed a method that enable information distribution to terminals over a wide area by using mobile vehicles equipped with wireless LAN access points. However, conventional researches consider information which size is a few Byte. Therefore, they did not consider a large amount of information which size is about 10Mbyte such as the evacuation map to deliver for multiple terminals. This paper proposes a method which combines an overhearing and a segmented file delivery method based …

Yuki Koizumi

Yuki Koizumi

Osaka University

IEICE Technical Report; IEICE Tech. Rep.

Evaluation of Large-capacity Content Transmission Equipment to Bundle12 and 21GHz-band Satellite Transmission Channels and IP Network--Laboratory Experiment for Flexible …

(in English) We have developed large-capacity content transmission equipment that bundles 21-and 12-GHz-band satellite channels and an IP network for providing immersive content such as volumetric content that is large capacity due to expanding spatial expressions. This equipment achieves a maximum transmission capacity of about 1 Gbps by transmitting a content to multiple transmission channels and network where the capacity and delay are different. For immersive media, we are developing video and audio formats and scene descriptions to facilitate AR/VR schemes and a variety of other content representations appropriate for any given viewer environment. Immersive content enables users to experience various viewer environments by producing content for each object. Therefore, we developed a function that specifies the transmission channels or network in accordance with the objects of the content …