Prospects of wide band gap material ZB-GaN over low band gap GaAs-based IMPATT Devices

Results of computer aided studies on mm-wave performance of GaAs (narrow band gap, E
_g
= 1.42 eV) and zinc-blende (ZB) phase GaN (wide band gap, E
_g
= 3.2 eV) double drift IMPATT diode for frequencies of operation in the range of 35 to 140 GHz indicate avalanche breakdown at very high electric field for ZB-GaN diode with exhibition of seven times higher breakdown voltage for ZB-GaN (331 V) compared to GaAs (45.4 V) making it possible to realize high RF power. However the values of device efficiency and value of diode negative resistance remains high for GaAs diodes.