MM-wave performance and avalanche noise estimation of hexagonal SiC and GaN IMPATTs for D-band applications

Abstract

The mm-wave as well as avalanche noise properties of IMPATT diode at D-band are efficiently estimated, with different poly-types of silicon carbide (SiC) and GaN as base materials, using advanced computer simulation techniques developed by the authors. The breakdown voltage of 4H-SiC (180 V) is more than the same for 6H-SiC, ZB- and Wz-GaN-based diode of 170,158, and 160 V, respectively. Similarly, the efficiency (14.7%) is also high in the case of 4H-SiC as compared with 6H-SiC and GaN-based diode. The study indicates that 4H-SiC IMPATT diode is capable of generating high RF power of about 8.38 W as compared with GaN IMPATT diode due to high breakdown voltage and negative resistance for the same frequency of operation. It is also observed that Wz-GaN exhibits better noise behavior 7.4 × 10−16 V2 s than SiC (5.16 × 10−15 V2 s) for IMPATT operation at 140 GHz. A comparison between the power output and noise from both the device reveals that Wz-GaN would be a suitable base material for high-power application of IMPATT diode with moderate noise.

Influence of the anisotropy on the performance of D-band SiC IMPATT diodes

“…In recent years, extensive research is being carried out for development of high-power IMPATT devices in millimeter-wave regime to meet the rising demand of high-power solid-state sources. The material parameters which are responsible for heat generation and dissipation in IMPATT diodes limit the output power of conventional Si and GaAs IMPATT diodes at a particular frequency [3]. In order to realize high-power, high-frequency IMPATT sources, wide bandgap semiconductor materials such as SiC and GaN have aroused a lot of interest as an attractive IMPATT diodes material for its high critical field, wide band gap and high thermal conductivity [4][5][6][7][8].…”

“…In order to realize high-power, high-frequency IMPATT sources, wide bandgap semiconductor materials such as SiC and GaN have aroused a lot of interest as an attractive IMPATT diodes material for its high critical field, wide band gap and high thermal conductivity [4][5][6][7][8]. For D-band applications, it is found that 4H-SiC IMPATT diode is capable of generating higher RF power density, while GaN IMPATT diode exhibits better noise behavior [3,9]. However, P-doping is a problem for GaN-based IMPATT diodes.…”