P-I-N photodiodes for optical control of microwave circuits

The full-device model of the p-i-n photodiode based on a harmonic balance method and drift-diffusion description of charge carrier transport in semiconductor heterostructure in time domain, taking into account external equivalent circuit, is developed. Computer simulation of p-n junction capacitance and resistance under different optical powers in the frequency range up to 60 GHz and zero bias voltage is presented. The influence of such photodiode design parameters as thickness, concentration, absorption coefficient, and charge carriers' life time of the absorption layer on the p-n junction capacitance ratio under different control optical powers is studied.