Investigation on annular-ring patch antenna with EBG structure

An annular-ring loaded circular patch antenna with slot-ring array of EBG cells on the ground plane is presented. A comparison is made between the annular ring loaded patch on a conventional PEC groundplane and the same patch on a groundplane with a 2times2, a 4times4 and a 6times6 slot-ring EBG array. It was found that the annular-ring patch antenna with a 4 times 4 slot-ring array in the ground plane is superior in the overall performance (gain, impedance and axial-ratio bandwidth). The array of EBG was found to improve gain by 3.5dB and increase the bandwidth of input impedance by about 60% (from 56 MHz to 85 MHz) and the bandwidth of axial ratio increased by about 70% (from 14 MHz to 24 MHz).