Temperature rise in microwave p-i-n diodes: A computer aided analysis

Results of a computer aided thermal analysis of microwave p-i-n diodes are presented in this paper. The nonlinear heat flow equations in one dimension are solved using the central finite difference method of Leibman's formulation taking into account the temperature dependence of thermal conductivity and specific heat. Results are presented showing the temperature profile inside the device as a function of microwave pulsewidth and power dissipation. The effect of a heat sink on the temperature rise is also shown. The main conclusion arrived at is that the nonlinear thermal properties lead to higher temperature rise in the device and larger thermal time constants than could be expected otherwise. The method used for calculation is applicable for other solid state devices like the TRAPATT, the fast recovery thyristor, and power transistors where similar orders of power levels are involved. © 1981.