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 withoutloading the conventional polarizer, which avoids the extra lossand the co-design difficulty. Specifically, by use of the polarizationconverting radiator, the quasi-TEM mode in the parallel platewaveguide (PPW) can easily excite the CP radiation withoutthe mode transition. This leads to a lower profile. With theinherent 90 degrees phase difference between the orthogonal polarizationcomponents of the radiator, the wide CP bandwidth is realized.By use of the comb-like structure, the mutual couplings alongtwo directions are simultaneously suppressed to realize the largebeam scanning range in 2-D. In addition, the width taper andthe accurate phase sampling by the input waveguides, whichconnects the PPW and the radiators, also enhance the operationbandwidth and the beam scanning range, respectively. As a result,the operation band can be from 27.5 to 31.0 GHz. The beamscanning range can be up to +/- 60 degrees. The axial ratios (ARs) arebelow 3 dB within the bandwidth and the beam scanning range.The height of the antenna is 0.98 lambda 0