Research on GaN-Based RF Devices: High-Frequency Gate Structure Design, Submicrometer-Length Gate Fabrication, Suppressed SCE, Low Parasitic Resistance, Minimized Current Collapse, and Lower Gate Leakage

2021 ◽  
Vol 22 (4) ◽  
pp. 34-48
Author(s):  
Yue Hao ◽  
Xiaohua Ma ◽  
Minhan Mi ◽  
Lin-An Yang
Keyword(s):  
High Frequency ◽  
Structure Design ◽  
Gate Leakage ◽  
Current Collapse ◽  
Parasitic Resistance ◽  
Gate Structure ◽  
Rf Devices

High-Frequency Properties of Permalloy Nanowire Arrays for RF Devices

2008 ◽  
Author(s):  
Hanqiao Zhang ◽  
Chunrong Song ◽  
Ralu Divan ◽  
Axel Hoffmann ◽  
Pingshan Wang
Keyword(s):  
High Frequency ◽  
Nanowire Arrays ◽  
Rf Devices ◽  
Frequency Properties

scholarly journals Research on the Vibration Insulation of High-Speed Train Bogies in Mid and High Frequency

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Jia Liu ◽  
Xuesong Jin
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Structure Design ◽  
High Speed Train ◽  
Bogie Frame ◽  
Explicit Finite Element ◽  
Vibration Transmissibility ◽  
Structure Improvement ◽  
Polygonal Wear ◽  
Stiffness And Damping

According to a large amount of the test data, the mid and high frequency vibrations of high-speed bogies are very notable, especially in the 565~616 Hz range, which are just the passing frequencies corresponding to the 22nd to 24th polygonal wear of the wheel. In order to investigate the main cause of wheel higher-order polygon formation, a 3D flexible model of a Chinese high-speed train bogie is developed using the explicit finite element method. The results show that the couple vibration of bogie and wheelset may lead to the high-order wears of wheel. In order to reduce the coupled resonance of the wheelset and the bogie frame, the effects of the stiffness and damping of the primary suspensions, wheelset axle radius, and bogie frame strength on the vibration transmissibility are discussed carefully. The numerical results show that the resonance peaks in high frequency range can be reduced by reducing the stiffness of axle box rotary arm joint, reducing the wheelset axle radius or strengthening the bogie frame location. The related results may provide a reference for structure improvement of the existing bogies and structure design of the new high-speed bogies.

scholarly journals A Strategic Review on Growth of InP on Silicon Substrate for Applications in High Frequency RF Devices

2012 ◽  
pp. 51-56
Author(s):  
Umesh.P. Gomes ◽  
Mr. Kuldeep ◽  
S. Rathi ◽  
Dhrubes Biswas
Keyword(s):  
High Frequency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
High Electron Mobility Transistors ◽  
Low Noise ◽  
Superior Performance ◽  
High Electron ◽  
Electron Mobility Transistors ◽  
Strategic Review ◽  
Rf Devices

A review is presented on the advances in InAlAs/InGaAs High Electron Mobility transistors (HEMT) on silicon substrates for high frequency and low noise applications. Although InAlAs/InGaAs HEMTs on InP and GaAs substrates have been much appreciated due to their superior performance, their widespread applications have been hindered due to higher cost of the substrates. Silicon has been used as an alternative substrate considering the benefits of low cost, technological maturity and integration of III-V and silicon technology inspite of the constraints like lattice mismatch and large difference in thermal expansion coefficient.

scholarly journals Reliability Concerns due to Self-Heating effects in GaN HEMTs

2013 ◽  
Vol 8 (2) ◽  
pp. 78-82
Author(s):  
B. Padmanabhan ◽  
D. Vasileska ◽  
S. M. Goodnick
Keyword(s):  
High Power ◽  
High Frequency ◽  
Additional Problem ◽  
Bias Stress ◽  
Self Heating ◽  
Current Collapse ◽  
Heating Effects ◽  
Dc Bias ◽  
Gan Hemts

Current collapse phenomenon that occurs in GaN HEMTs under a moderately large DC bias stress, poses serious problems for usage of GaN technology in high-power high-frequency applications from a reliability standpoint. Additional problem in these devices operated at high biases is the appearance of self-heating effects that degrade device characteristics and, as shown in this work further amplify the problem of current collapse by changing the device electrostatics.

scholarly journals AlGaN/GaN MIS-HEMT with PECVD SiNx, SiON, SiO2 as Gate Dielectric and Passivation Layer

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 416 ◽  
Author(s):  
Kuiwei Geng ◽  
Ditao Chen ◽  
Quanbin Zhou ◽  
Hong Wang
Keyword(s):  
Leakage Current ◽  
Gate Dielectric ◽  
Deep Trap ◽  
Trap Density ◽  
Interface Traps ◽  
Gate Leakage Current ◽  
Gate Leakage ◽  
Metal Insulator ◽  
Current Collapse ◽  
Gate Leakage Current Density

Three different insulator layers SiNx, SiON, and SiO2 were used as a gate dielectric and passivation layer in AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMT). The SiNx, SiON, and SiO2 were deposited by a plasma-enhanced chemical vapor deposition (PECVD) system. Great differences in the gate leakage current, breakdown voltage, interface traps, and current collapse were observed. The SiON MIS-HEMT exhibited the highest breakdown voltage and Ion/Ioff ratio. The SiNx MIS-HEMT performed well in current collapse but exhibited the highest gate leakage current density. The SiO2 MIS-HEMT possessed the lowest gate leakage current density but suffered from the early breakdown of the metal–insulator–semiconductor (MIS) diode. As for interface traps, the SiNx MIS-HEMT has the largest shallow trap density and the lowest deep trap density. The SiO2 MIS-HEMT has the largest deep trap density. The factors causing current collapse were confirmed by Photoluminescence (PL) spectra. Based on the direct current (DC) characteristics, SiNx and SiON both have advantages and disadvantages.

Novel High Precision Digital Curvilinear Displacement Sensor

2010 ◽  
Vol 44-47 ◽  
pp. 326-329
Author(s):  
Liang Hua ◽  
Ju Ping Gu ◽  
Yu Jian Qiang ◽  
Lin Lin Lv
Keyword(s):  
High Precision ◽  
High Frequency ◽  
Low Cost ◽  
Structure Design ◽  
Displacement Sensor ◽  
General Application ◽  
Interface Circuit ◽  
Displacement Sensors ◽  
Working Principle ◽  
Displacement Based

This study put forward a novel high precision digital curvilinear displacement sensor.The high frequency pulses were used to represent the magnitude of curvilinear displacement based on geometry analyse. The mechanical structure design of the sensor was completed. The working principle of curvilinear displacement sensor was analyzed in detail. The hardware and software design of the interface circuit of the sensor was completed and the performance of the sensor was analyzed. Compared with the traditional curvilinear displacement sensors, the sensor proposed in this paper has features of high precision, efficiency, explicit structure, low cost, wide measuring range, no need to adjust zero and it has general application value in industry field.

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