Radiation pattern computation of cavity-backed and probe-fed stacked microstrip patch arrays

In this paper, two different methods based on Floquet's harmonic expansion of the electromagnetic field in half-space are proposed to determine the active element pattern of infinite planar arrays. They allow us to obtain the radiating characteristics without the limitations of the conventional method from the active reflection coefficient. Both are applied to analyze the scan performance in the case of probe-fed and cavity-backed microstrip arrays from its generalized scattering matrix (GSM), computed previously with a full wave numerical procedure. Numerical results are presented and compared with other techniques.