Transient analysis of active antenna based on time-domain model

A modular method is presented for transient analysis of an active antenna which consists of a microstrip antenna and a Gunn diode. By use of deconvolution, the transient input impedance of the microstrip antenna is firstly extracted from its terminal voltage and current with step pulse excitation which are simulated by finite-difference time-domain method (FDTD). Then connecting the transient impedance with the lumped equivalent circuit of Gunn diode and using transient analysis of the discrete-time system, we obtain the oscillation voltage and frequencies of the active antenna. Comparison with the direct FDTD simulation shows a good agreement and four limes reduction of computational time.