An investigation of the near-field distribution of conventional electromagnetic bandgap resonator antennas

Amplitude and phase distributions are investigated across apertures of two typical electromagnetic bandgap resonator antennas (ERAs) created with moderately and highly reflective un-printed superstrates cover. It was found that the field distribution is non-uniform, especially when superstrates is not highly reflective. That affects the radiation characteristics of the antenna. To improve the phase distribution, and hence the radiation performance, a phase correcting structure (PCS) is proposed.