Pattern Equalization of Circular Patch Antennas Using Different Substrate Permittivities and Ground Plane Sizes

A very unique phenomenon of circular patch antennas (CPA) for obtaining equal E- and H-plane co-polarization patterns, using varying substrate permittivities and ground plane sizes, is investigated in this paper. Pattern equalization is studied for the dominant and the first few higher order modes of the circular patch antenna, using different substrate permittivities (ε_r) for the infinite ground plane case, and also by varying the ground plane sizes for the finite ground plane case. The angular range, at which the E- and H-plane patterns can be made equal, decreases with increased mode numbers. Also, for a given ε_r and mode number, there exists a specific ground plane size, which provides nearly equal E- and H-plane co-polarization patterns. For higher order modes, larger ground planes and higher dielectric permittivities are required to obtain pattern equalization with a greater angular range.