Analysis of microwave circuits by incorporating SPICE into FDTD code

A modeling approach of incorporating SPICE into FDTD code for analysis of microwave active circuits is presented, and a set of communication agreement is developed to control the data exchange between FDTD and SPICE. With this agreement, it is very convenient for FDTD modeling of microwave circuits with random number of ports. Two typical microwave circuits are simulated by this approach as examples to illustrate the efficiency of the proposed approach.