A two-dimensional transmission line matrix microwave field simulator using new concepts and procedures

A two-dimensional field simulator for microwave circuit modeling is described. It incorporates a number of recently developed concepts and advanced transmission line matrix (TLM) procedures. In particular, a discrete Green´s function concept based on P.B. John´s and K. Akhlarzad´s time-domain diakoptics is realized, providing a high level of processing power through modularization of large structures at the field level, simulation of wideband matched loads or absorbing walls, modeling of frequency-dispersive boundaries in the time domain, and large-scale numerical preprocessing of passive structures. Nonlinear field modeling concepts are also implemented in the TLM field simulator. It can analyze two-dimensional circuits of arbitrary geometry containing both linear and nonlinear media. The circuit topology is input graphically. Both time-domain and frequency-domain responses can be computed and displayed. The capabilities and limitations of the simulator are discussed, and several microstrip and waveguide components are modeled to demonstrate its important features