Incorporating SPICE into an FDTD code

A software package that employs a combination of the finite-difference time-domain (FDTD) electromagnetic simulations with SPICE analysis has been developed. The characteristic features are: the ability of treating highly complex SPICE models, including integrated circuits; practically unlimited number of ports, or linking points between the SPICE and FDTD nodes; the coherence of the work of all the parts, so that no logical ambiguity or causality problems arise. An appropriate data structure minimizes the efforts of the user to construct a consistent input for both FDTD and SPICE parts. Examples of simulation results are shown, and the difference with pure SPICE results is discussed.