Analysis of a Simple Single-Layer Broadband Patch Antenna using Characteristic Mode

A simple single-layer broadband patch antenna is proposed. The antenna consists five square patches. The surrounding four patches are connected with the ground by shorting pins and the middle patch is excited by a probe feed. Three excited modes are analyzed for bandwidth enhancement through characteristic mode analysis. The prototype ($0.933 \lambda_{0} \times_{0} 0.933 \lambda_{0} \times 0.037 \lambda_{0}$ at 7 GHz) is simulated, showing a 34% 10 dB impedance bandwidth and 2.1-7.5 dBi boresight gain with a relatively stable pattern.