The prospects of InP/GaInAs heterojunction is explored for application as a double avalanche region IMPATT diode using some computer simulation programs developed by us. Our results indicate that, with a suitably tailored GaInAs layer width, the proposed heterojunction DAR diode, while permitting multi-band tuning facility, would be less noisy with a moderate power. A noise measure of 8.7 dB at 84 GHz from this diode is note worthy. (C) 2003 Elsevier Ltd. All rights reserved.