ACCURATE ANALYSIS AND SYNTHESIS OF ANNULAR RING MICROSTRIP ANTENNAS

A fast accurate analytical model is developed for the analysis and syn thesis of annular-ring multilayer printed antennas. It uses a variatio nal definition of the surface charge density to take into account the shape of the radiating element. The input impedance is determined from an equivalent electrical circuit. A computer algebra system is used f or the theoretical polynomial expression of the zeros of the character istic equation. Numerical results are given and compared with experime nts and rigorous models. A high level of agreement is observed. The ve ry short computing time allows inclusion in a microstrip antenna compu ter aided design system.