Analysis of finite-phased arrays of aperture-coupled stacked microstrip antennas

Analytical results for finite-phased arrays of aperture-coupled stacked microstrip antennas are presented. In order to evaluate the characteristics of aperture-coupled microstrip antennas in a finite array and derive the moment-method solutions for the unknown current distributions on the patches and slots, the reciprocity theorem and the spectral domain Green's functions for a dielectric slab are used. Various sized arrays are considered and compared with solutions for an infinite array. Numerical results are presented to illustrate the input impedance, mutual coupling, active reflection coefficient versus scan angle, radiation efficiency, and active-element gain patterns.