scholarly journals A GaN HEMT Amplifier Design for Phased Array Radars and 5G New Radios

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 398
Author(s):  
Dawid Kuchta ◽  
Daniel Gryglewski ◽  
Wojciech Wojtasiak
Keyword(s):  
Output Power ◽  
Power Efficiency ◽  
High Electron Mobility Transistors ◽  
Phase Changes ◽  
High Electron ◽  
Frequency Range ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
Amplifier Design ◽  
Gan On Si

Power amplifiers applied in modern active electronically scanned array (AESA) radars and 5G radios should have similar features, especially in terms of phase distortion, which dramatically affects the spectral regrowth and, moreover, they are difficult to be compensated by predistortion algorithms. This paper presents a GaN-based power amplifier design with a reduced level of transmittance distortions, varying in time, without significantly worsening other key features such as output power, efficiency and gain. The test amplifier with GaN-on-Si high electron mobility transistors (HEMT) NPT2018 from MACOM provides more than 17 W of output power at the 62% PAE over a 1.0 GHz to 1.1 GHz frequency range. By applying a proposed design approach, it was possible to decrease phase changes on test pulses from 0.5° to 0.2° and amplitude variation from 0.8 dB to 0.2 dB during the pulse width of 40 µs and 40% duty cycle.

IR Thermography for Temperature Measurements and Fault Location on AlGaN/GaN HEMTs and MMICs

2015 ◽  
Author(s):  
Lény Baczkowski ◽  
Franck Vouzelaud ◽  
Dominique Carisetti ◽  
Nicolas Sarazin ◽  
Jean-Claude Clément ◽  
...  
Keyword(s):  
Fault Location ◽  
Hot Spot ◽  
Life Time ◽  
High Electron Mobility Transistors ◽  
Junction Temperature ◽  
High Electron ◽  
Ir Thermography ◽  
Operating Life ◽  
Gan Hemt ◽  
Electron Mobility Transistors

Abstract This paper shows a specific approach based on infrared (IR) thermography to face the challenging aspects of thermal measurement, mapping, and failure analysis on AlGaN/GaN high electron-mobility transistors (HEMTs) and MMICs. In the first part of this paper, IR thermography is used for the temperature measurement. Results are compared with 3D thermal simulations (ANSYS) to validate the thermal model of an 8x125pm AIGaN/GaN HEMT on SiC substrate. Measurements at different baseplate temperature are also performed to highlight the non-linearity of the thermal properties of materials. Then, correlations between the junction temperature and the life time are also discussed. In the second part, IR thermography is used for hot spot detection. The interest of the system for defect localization on AIGaN/GaN HEMT technology is presented through two case studies: a high temperature operating life test and a temperature humidity bias test.

scholarly journals Development of AlGaN/GaN/SiC high-electron-mobility transistors for THz detection

2018 ◽  
Vol 58 (2) ◽  
Author(s):  
Vytautas Jakštas ◽  
Justinas Jorudas ◽  
Vytautas Janonis ◽  
Linas Minkevičius ◽  
Irmantas Kašalynas ◽  
...  
Keyword(s):  
Electron Mobility ◽  
Schottky Diodes ◽  
Electronic Devices ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
High Electron Mobility ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
Steady Current ◽  
Improved Performance

This paper reports on the AlGaN/GaN Schottky diodes (SDs) and high-electron-mobility transistors (HEMTs) grown on a semi-insulating SiC substrate. The electronic devices demonstrate an improved performance in comparison with the ones processed on a sapphire substrate. Both the SDs and HEMTs show much smaller leakage current density and a higher ION/IOFF ratio, reaching values down to 3.0±1.2 mA/cm2 and up to 70 dB under the reverse electric field of 340 kV/cm, respectively. The higher thermal conductivity of the SiC substrate leads to the increase of steady current and transconductance, and better thermal management of the HEMT devices. In addition, a successful detection of terahertz (THz) waves with the AlGaN/GaN HEMT is demonstrated at room temperature. These results open further routes for the optimization of THz designs which may result in development of novel plasmonic THz devices.

scholarly journals Impact of Gamma Radiation on Dynamic RDSON Characteristics in AlGaN/GaN Power HEMTs

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2760 ◽  
Author(s):  
Pedro J. Martínez ◽  
Enrique Maset ◽  
Pedro Martín-Holgado ◽  
Yolanda Morilla ◽  
David Gilabert ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Wide Band ◽  
High Electron Mobility Transistors ◽  
Dynamic Resistance ◽  
High Electron ◽  
Power Switching ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
Free Current ◽  
60Co Gamma Radiation

GaN high-electron-mobility transistors (HEMTs) are promising next-generation devices in the power electronics field which can coexist with silicon semiconductors, mainly in some radiation-intensive environments, such as power space converters, where high frequencies and voltages are also needed. Its wide band gap (WBG), large breakdown electric field, and thermal stability improve actual silicon performances. However, at the moment, GaN HEMT technology suffers from some reliability issues, one of the more relevant of which is the dynamic on-state resistance (RON_dyn) regarding power switching converter applications. In this study, we focused on the drain-to-source on-resistance (RDSON) characteristics under 60Co gamma radiation of two different commercial power GaN HEMT structures. Different bias conditions were applied to both structures during irradiation and some static measurements, such as threshold voltage and leakage currents, were performed. Additionally, dynamic resistance was measured to obtain practical information about device trapping under radiation during switching mode, and how trapping in the device is affected by gamma radiation. The experimental results showed a high dependence on the HEMT structure and the bias condition applied during irradiation. Specifically, a free current collapse structure showed great stability until 3.7 Mrad(Si), unlike the other structure tested, which showed high degradation of the parameters measured. The changes were demonstrated to be due to trapping effects generated or enhanced by gamma radiation. These new results obtained about RON_dyn will help elucidate trap behaviors in switching transistors.

scholarly journals Development of Catalytic-CVD SiNx Passivation Process for AlGaN/GaN-on-Si HEMTs

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 842 ◽  
Author(s):  
Myoung-Jin Kang ◽  
Hyun-Seop Kim ◽  
Ho-Young Cha ◽  
Kwang-Seok Seo
Keyword(s):  
Chemical Vapor ◽  
Drain Current ◽  
High Electron Mobility Transistors ◽  
Breakdown Field ◽  
High Electron ◽  
Electron Mobility Transistors ◽  
Current Collapse ◽  
Passivation Process ◽  
Gan On Si ◽  
Sinx Film

We optimized a silicon nitride (SiNx) passivation process using a catalytic-chemical vapor deposition (Cat-CVD) system to suppress the current collapse phenomenon of AlGaN/GaN-on-Si high electron mobility transistors (HEMTs). The optimized Cat-CVD SiNx film exhibited a high film density of 2.7 g/cm3 with a low wet etch rate (buffered oxide etchant (BOE) 10:1) of 2 nm/min and a breakdown field of 8.2 MV/cm. The AlGaN/GaN-on-Si HEMT fabricated by the optimized Cat-CVD SiNx passivation process, which had a gate length of 1.5 μm and a source-to-drain distance of 6 μm, exhibited the maximum drain current density of 670 mA/mm and the maximum transconductance of 162 mS/mm with negligible hysteresis. We found that the optimized SiNx film had positive charges, which were responsible for suppressing the current collapse phenomenon.

Trapping Effects Dependence on Electron Confinement in Ultrashort GaN-on-Si High-Electron-Mobility Transistors

2012 ◽  
Vol 5 (3) ◽  
pp. 034103
Author(s):  
Farid Medjdoub ◽  
Damien Ducatteau ◽  
Malek Zegaoui ◽  
Bertrand Grimbert ◽  
Nathalie Rolland ◽  
...  
Keyword(s):  
Electron Mobility ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
High Electron Mobility ◽  
Electron Confinement ◽  
Electron Mobility Transistors ◽  
Gan On Si ◽  
Trapping Effects

scholarly journals Comparisons on Different Innovative Cascode GaN HEMT E-Mode Power Modules and Their Efficiencies on the Flyback Converter

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5966
Author(s):  
Chih-Chiang Wu ◽  
Ching-Yao Liu ◽  
Sandeep Anand ◽  
Wei-Hua Chieng ◽  
Edward-Yi Chang ◽  
...  
Keyword(s):  
High Electron Mobility Transistors ◽  
Switching Frequency ◽  
High Electron ◽  
Flyback Converter ◽  
Gan Hemt ◽  
Electron Mobility Transistors ◽  
High Switching Frequency ◽  
In Series ◽  
Source Voltage ◽  
A Charge

The conventional cascode structure for driving depletion-mode (D-mode) gallium nitride (GaN) high electron mobility transistors (HEMTs) raises reliability concerns. This is because of the possibility of the gate to source voltage of the GaN HEMT surging to a negative voltage during the turn off transition. The existing solutions for this problem in the literature produce additional drawbacks such as reducing the switching frequency or introducing many additional components. These drawbacks may outweigh the advantages of using a GaN HEMT over its silicon (Si) alternative. This paper proposes two innovative gate drive circuits for D-mode GaN HEMTs—namely the GaN-switching based cascode GaN HEMT and the modified GaN-switching based cascode GaN HEMT. In these schemes, the Si MOSFET in series with the D-mode GaN HEMT is always turned on during regular operation. The GaN HEMT is then switched on and off by using a charge pump based circuit and a conventional gate driver. Since the GaN HEMT is driven independently, the highly negative gate-to-source voltage surge during turn off is avoided, and in addition, high switching frequency operation is made possible. Only two diodes and one capacitor are used in each of the schemes. The application of the proposed circuits is experimentally demonstrated in a high voltage flyback converter, where more than 96% efficiency is obtained for 60 W output load.

Improving Efficiency in Downhole Power Converters using GaN Technology

2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000097-000105
Author(s):  
Gary Hanington
Keyword(s):  
Power Efficiency ◽  
Elevated Temperatures ◽  
Extreme Environments ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
The Past ◽  
Silicon Devices ◽  
Electron Mobility Transistors ◽  
Squeeze Out ◽  
Bandgap Semiconductors

Abstract In downhole applications, the ability to convert wildly varying wireline voltages standard +/− 15 VDC stretches the limit on switching converters whose components have to be rugged, compact, and offer low thermal paths to surrounding metal housings. Many times the incoming voltages exceed 200V with spikes above 500 quite common. Functioning in extreme environments up to 200 degrees Celsius requires the designer to squeeze out the highest power efficiency possible and every percent increase is an important milestone. Over the past three decades silicon devices were the only technology available that could be made to work at such temperatures, almost always bypassing the manufacturer's maximum specifications. In the past several years wide bandgap semiconductors have become available that offer new possibilities for operation at elevated temperatures. This paper discusses the efficiency improvements when silicon power devices are replaced with gallium nitride based components. By utilizing GaN High Electron Mobility Transistors (HEMTs) in an existing H bridge phase shifted converter, efficiency improvements of up to 9% have been achieved at 175 °C operation. Advantages of HEMT devices compared to silicon are discussed and associated loss mechanisms of both are compared.

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