A modal approach for the analysis of the aperture-coupled multi-layer microstrip array

Microstrip array antennas consisting of printed elements integrated with feed network and active circuits in multiple dielectric layers are assuming an important role for telecommunication applications. The main consideration which supports the multi-layer architecture for microstrip antennas is to separate the radiator and the feed sections by means of a ground plane with coupling apertures, in order to avoid the interference of the feed network on the radiation of the patches. The complexity of the microstrip array configuration, in terms of involved geometries and design parameters, requires a versatile and powerful electromagnetic approach for a both accurate and time limited analysis of the structure. The theoretical model description and the validation measurements are the subject of the paper