Wideband and Wide-Scan-Angle Circularly Polarized VICTS-Like Antenna With Polarization Converting Radiator for Ka-Band SatCom

A wideband wide-scan-angle circular polarization (CP) variable inclination continuous transverse stub-like (VICTS-like) antenna for the Ka-band Satellite communication (SatCom) is proposed in this article. The antenna achieves the CP without loading the conventional polarizer, which avoids the extra loss and the co-design difficulty. Specifically, by use of the polarization converting radiator, the quasi-TEM mode in the parallel plate waveguide (PPW) can easily excite the CP radiation without the mode transition. This leads to a lower profile. With the inherent 90° phase difference between the orthogonal polarization components of the radiator, the wide CP bandwidth is realized. By use of the comb-like structure, the mutual couplings along two directions are simultaneously suppressed to realize the large beam scanning range in 2-D. In addition, the width taper and the accurate phase sampling by the input waveguides, which connects the PPW and the radiators, also enhance the operation bandwidth and the beam scanning range, respectively. As a result, the operation band can be from 27.5 to 31.0 GHz. The beam scanning range can be up to ±60°. The axial ratios (ARs) are below 3 dB within the bandwidth and the beam scanning range. The height of the antenna is
$0.98\lambda 0$
.