Dual-CP Antenna with Wide-HPBW and Wide-ARBW Performance for Wide-Angle Scanning Phased Array

In this communication, a novel dual circularly polarized (CP) antenna with both of wide half-power beamwidth (HPBW) and wide axial ratio beamwidth (ARBW) is proposed. Based on the septum circular polarizer, the principle about HPBW improvement of its | E _θ | and | E _φ | components is extensively studied. It proves that the metal rings around the top surface could be used to enhance the low elevation gain and extend its HPBW of | E _θ | components. Subsequently, a set of slots is introduced on the waveguide to expand the HPBW of its | E _φ | component. With these arrangements, both of ARBW and HPBW parameters of the antenna are simultaneously widened, while keeping wide impedance bandwidth as desired. Additionally, the antenna element is constructed as the 1×8 phased array for wide-angle scanning in such a way that the array antenna can satisfactorily achieve wide CP scanning range and stable radiation pattern. In final, the proposed antenna is designed, fabricated and measured. The results evidently reveal that the proposed element can simultaneously achieve 3dB HPBW and 3dB ARBW in the range of 130° in 3.8-4.2 GHz, and its inspired array can effectively achieve beam scanning from -60 ° to 60 ° in 3.9-4.2GHz.