Sixteen-Element Broadband Circularly Polarized Microstrip Antenna Array for S-Band

In this paper, a broadband circularly polarized (CP) microstrip antenna array for S-band is proposed. The antenna consists of a parallel rotating feed network, sixteen units with cut corners, adding rectangular perturbations, and the guided patches with 45◦ oblique rectangular slots. The guided patches increase the impedance bandwidth of the antenna, and the feed network with a 90◦ phase difference increases the axial ratio bandwidth. The simulation and measurement results show that the S11 curve is 2.45 ∼ 4.15 GHz; the impedance bandwidth is 51.5%; the frequency with the axial ratio less than 3 dB is 2.54 ∼ 3.74 GHz; the working bandwidth is 1.2 GHz; the CP bandwidth is 38.2%; the gain is 18.72 dB at the S-band center frequency. The advantages of the designed antenna are high gain, wide bandwidth, and a good radiation pattern. It can be applied to early warning radar in S-band. It also completely covers China Mobile’s 2.6 GHz spectrum and can be used as a base station antenna if taking no account of the polarization method. The antenna has a simple structure, which is suitable for applications. © 2022, Electromagnetics Academy. All rights reserved.