Cavity Mode Analysis for a Rectangular Patch with a Shorting Pin

A rigorous treatment for the cavity modes on a rectangular patch with a shorting pin is presented. It is shown that the dominant mode has a reduced resonant frequency relative to that of the patch with no short. Thus the shorted patch can act as a compact antenna at a prescribed operating frequency. The theory is supported by simulation results obtained by the Zealand IE3D simulator and by experimental measurements. The present theory leads to an accurate initial design for a shorted rectangular patch antenna with a prescribed operating frequency.