Broad-band cavity-backed and capacitively probe-fed microstrip patch arrays

A hybrid full wave method for the analysis of probe-fed infinite phased arrays of single and stacked microstrip patches, backed by metallic cavities, is applied to investigate the combined utilization of the capacitive probe-feeding technique and the cavity enclosure of microstrip patches. The goal is to obtain broad-band microstrip antennas on thick substrates without the limitations due to the generation of surface waves of the conventional microstrip antennas on infinite substrates. A design procedure for the capacitive coupling is investigated and theoretical results for the active input impedance and radiation characteristics of different wide-band antenna designs are presented.