Analysis of an Electromagnetically Coupled Microstrip Ring Antenna Using an Extended Feedline

Abstract

A new method for the computation of input impedance of an annular ring microstrip antenna, fed electromagnetically by a microstrip line, and operating in its fundamental mode is presented. The method based on cavity model in conjunction with circuit theory is compared with simulation (IE3D™) and measurement based results. It is shown that this method of computation leads to accurate prediction of impedance for such structures with minimum of computational complexity, thereby making it an attractive tool for accurate and quick design estimate for many applications.