Abstract
This work is an effort to investigate and derive a simple equivalent circuit model to represent an electromagnetically coupled microstrip patch antenna. This provides a simple approach to the complicated electromagnetic coupling behaviour in the patch. A simplified theory based on the broadside coupled line and improved transmission line theories is developed to derive the equivalent circuit of EM coupled patch antenna. The design parameters are determined from the above mentioned theory. Computer programs are developed to provide a practical design of such antennas without involving complicated, time consuming, rigorous methods. A number of sample patches are designed, made and tested to verify the theory. These elements are also incorporated into an array to evaluate their performance in an array environment. The impedance and pattern measurements are made for comparison with theoretical results.