Heterojunction DDR THz IMPATT diodes based on Al_xGa_(1-x)N/GaN material system

摘要

Simulation studies are made on the large-signal RF performance and avalanche noise properties of heterojunction double-drift region (DDR) impact avalanche transit time (IMPATT) diodes based on Al_xGa_(1-x)N/GaN material system designed to operate at 1.0 THz frequency. Two different heterojunction DDR structures such as n-Al_(0.4)Ga_(0.6)N/p-GaN and n-GaN/p-Al_(0.4)Ga_(0.6)N are proposed in this study. The large-signal output power, conversion efficiency and noise properties of the heterojunction DDR IMPATTs are compared with homojunction DDR IMPATT devices based on GaN and Al_(0.4)Ga_(0.6)N. The results show that the n-Al_(0.4)Ga_(0.6)N/p-GaN heterojunction DDR device not only surpasses the n-GaN/p-Al_(0.4)Ga_(0.6)N DDR device but also homojunction DDR IMPATTs based on GaN and Al_(0.4)Ga_(0.6)N as regards large-signal conversion efficiency, power output and avalanche noise performance at 1.0 THz.