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

In this paper, two different methods based on the Floquet's harmonic expans ion of the electromagnetic field in halfspace 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 m ethod from the active reflection coefficient. Both are applied to analyze t he scan performance in the case of probe-fed and cavity-backed microstrip a rrays from its generalized scattering matrix (GSM), computed previously wit h a full wave numerical procedure. Numerical results are presented and comp ared with other techniques.