Broadband Circularly Polarized Cavity-Backed Slot Antenna Array With Four Linearly Polarized Disks Located in a Single Circular Slot

A novel cavity-backed slot antenna array with broadband circularly polarized (CP) property is presented in this letter. A corporate feed network composed of three Wilkinson power dividers is applied to sequentially rotated feed four linearly polarized disks that are located in a cavity-backed circular slot. The measured 3-dB axial-ratio (AR) bandwidth of the array is 54.5%, and the 10-dB return loss bandwidth is 92.1%. The 3-dB gain bandwidth is about 50.8% with the peak gain 9.9 dBic.