A Curl Element-Based Wideband High Gain Circularly Polarized Planar Antenna for 5G Millimeter-Wave System

In this paper, a staircase curl element-based circularly polarized planar antenna with high performance for Fifth-generation millimeter-wave communication system is proposed. The developed antenna has a stacked layout with the radiating element containing $2 \times 2$ staircase curl patches, which are rotated clockwise by 90° in sequence and placed above a custom-designed driven element. The driven element comprised a 270° loop strip and a rectangular patch, which can generate a stabilized 90° phase difference at the end of the strip, thus resulting in enhanced axial ratio bandwidth (ARBW) and stable high gain. The simulated results show that the antenna achieving a -10-dB fractional bandwidth of 50.6 %, and 3-dB ARBW of 65.7% along with a maximum gain of 10.2 dBic, respectively.