Effect of Asymmetric Structures On the Performance of AlGaN/GaN Bilateral IMPATT Device

The effect caused by asymmetric structures on the performance of the AlGaN/GaN bilateral impact-ionizat-ionavalanche-transit-time (BIMPATT) device is studied in this article. The asymmetric structures include the asymmetry of the bilateral channel lengths by changing the anode position and the asymmetry of the two-dimensional electron gas (2DEG) concentrations by changing the AlGaN thickness. The asymmetry affects the direct current (DC), radio frequency (RF), and noise characteristics of the BIMPATT. Large-signal analysis shows that the asymmetric structures improve the operating frequency but reduce the maximum power and efficiency of the BIMPATT. The asymmetric structures show better RF characteristics than the symmetric structure in the high-frequency band. At last, the asymmetric structures increase the noise performance of the BIMPATT. The reason for these phenomena is the asymmetry of avalanche ionization region and intensity caused by the asymmetry of device structure. This article provides more references for the design and performance optimization of the lateral IMPATT devices.