Abstract: An effective numerical method is presented for modeling slot antennas fed by the microstrip. The equivalence principle is applied so that an original problem can be divided into two isolated equivalence problems. With the discrete complex images method (DCIM) and RWG basis functions, we can give a full-wave analysis of equivalence problems in the spatial domain without the Sommerfeld integrals. These closed-form Green’s functions account for all radiation, surface-wave, and mutual-coupling effects. Triangular facets are used so that our method is suitable for analyzing a complex structure. Numerical results of two typical examples are given which validate this method.

Key words: equivalence principle, DCIM, Green's functions