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In recent years, with the fast development of semiconductor technology, as well as the material growth technology breakthrough, as the third generation of gallium nitride (GaN) semiconductor has been gradually showing its advantages, the two-dimensional electron gas density and saturation electron mobility rate, etc., based on gallium nitride (GaN) is also increasing. In the field of communications, radar, microwave, microwave power device performance requirements also increasingly high microwave power devices based on wide bandgap semiconductor material gallium nitride (GaN) is becoming a hot topic. This is in the context of this study, AlGaN / GaN heterojunction microwave power devices, materials preparation and device technology described, the basic characteristics of the GaN power devices, including: DC characteristics, current collapse, breakdown voltage and characterization. On this basis, focusing on the microwave properties of gallium nitride (GaN) power devices test were introduced, including: on-chip test, the separation device testing, small-signal test signal test, load-pull (Load Pull) test from test principle, the test program, carried out a detailed analysis of the test system. Due to the small-signal testing and large signal separation device tested and customized solutions that can be directly used, we design a test fixture for 3.7-4.2GHz. Although the use of the SOLT coaxial calibration test is simple, but with the gradual increase in frequency, the test fixture impact can not be ignored, we consider the use of the TRL calibration method. Vector network error model, the design of the 6 GHz TRL calibration standards, including: direct (Thru), short-circuit (Short), open circuit (Open), load (Load), the delay line (Delay Line). This calibration GaN HEMT 9mm device TRL calibration test, the gain S21 7.4dB higher than the the coaxial calibration test results 6.6dB. Can be found at 4GHz TRL calibration test to eliminate a part of fixture losses and thru the assessment found that indeed move to the measurement reference plane measured near. In addition, this paper also designed a removable clamp for de-embedding test, but for semi-fixture test and found that loss to be much larger than thru, this is actually difficult to get the fixture halves accurate S-parameter. Finally, the circuit model to simulate shell and tube, of QF051 tube shell parasitic extraction, simulation 4GHz when the S11, and the results are less TRL calibration measured, but the big difference with the coaxial calibration test This further illustrates the the TRL calibration test is indeed more accurate.
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