Design of Circular Polarization Antenna Array Based on Sequential Phase Feed Network

A novel circular polarized microstrip 4-unit array antenna based on sequential phase (SP) feed network is proposed in this paper. The proposed antenna is designed to work at 33 GHz. Four square tangential circular polarization patches are connected to the SP feeding network to form a 2×2 microstrip array to achieve better circular polarization performance. A metasurface superstrate is designed above the antenna to improve the antenna gain. Simulation results show that the return loss bandwidth of the proposed antenna for| S11| <; -10 dB is 10.1 GHz, and its circular polarization radiation bandwidth is 32.68-38GHz (16.1%) for axis ratio (AR) <; 3-dB. With the metasurface layer, the antenna gain can be further improved by 4dB.