Analysis of Aperture Coupled Microstrip Patch Antennas with a Superstrate Using the Space Domain Closed-Form Green`s Functions

Analysis of aperture-coupled microstrip antennas with a superstrate using space domain closed form Green's functions is presented. Integral equations are derived from applying the boundary conditions on the radiating patch, across the aperture, and on the microstrip feedline. The computation of space domain green's functions is performed using the closed-form. The solution of the integral equations is based on the method of moments. The information about the input impedance of the antenna is extracted from the electric current distribution on the microstrip feedline using the matrix pencil technique. The radiation pattern is obtained from the electric current distribution on the antenna's patch utilizing the asymptotic forms of sommerfeld integrals. The effect of considering a superstrate for different thicknesses and dielectric constants are examined. Numerical results are compared with other published and experimental results. The results show good agreement with prerions data.