A complete numerical simulation of a Baritt diode microstrip oscillator is described, and the important effects of diode and circuit temperature are discussed. Results of the numerical simulation are compared with thermal and electrical measurements on oscillator circuits and found to be in good agreement. The circuit model was used as a basis for the design of Baritt diode Doppler modules, indicating how frequency drift with ambient temperature may be improved. A C-band Doppler module was constructed which drifts less than 10 MHz between ??20??C and +40??C.