基于GaN肖特基二极管的200 GHz二倍频器研制

200 GHz doubler based on GaN Schottky diodes

摘要:

基于GaN肖特基二极管设计并实现了一款200 GHz高功率二倍频器。该倍频器采用高功率容量的氮化镓(GaN)肖特基二极管代替传统GaAs肖特基二极管，并结合高热导率的氮化铝(AlN)衬底，较大提升了倍频器的散热性能和输出功率；采用含有楔形膜片的悬置微带-波导过渡结构，通过插入标准矩形波导中的楔形膜片实现模式转换并使输入输出同向，实现倍频器的小型化。考虑到温度对二极管工作的影响，对传统二极管模型进行修正，并进行电热耦合仿真。实际测试结果表明，在500 mW连续波输入的情况下，该二倍频器在190~220 GHz频率范围内输出均高于20 mW，并在218 GHz实现了最大36 mW的功率输出，转换效率为7.2%。

Abstract:

A high-power frequency doubler at 200 GHz has been designed and implemented based on GaN Schottky diodes. This frequency doubler replaces traditional GaAs Schottky diodes with high-power-capacity Gallium Nitride(GaN) Schottky diodes and combines them with Aluminum Nitride(AlN) substrates, which have high thermal conductivity, significantly enhancing the heat dissipation and output power of the doubler. A suspended microstrip-waveguide transition structure with a wedge-shaped membrane is employed, which realizes mode conversion and codirectional input and output by inserting a wedge-shaped membrane into the standard rectangular waveguide, achieving miniaturization of the frequency doubler. Considering the impact of temperature on diode operation, the traditional diode model is modified, and electro-thermal coupled simulations are performed. Actual test results indicate that under 500 mW continuous-wave input, the doubler outputs more than 20 mW in the frequency range of 190~220 GHz and achieves a maximum output power of 36 mW at 218 GHz, with a conversion efficiency of 7.2%.