Wideband Dual-Circular-Polarization Antenna based on the Grooved-Wall Horn Antenna for Millimeter-Wave Wireless Communications

This paper presents a dual-circular-polarization (dual-CP) antenna based on a grooved-wall horn antenna working in the W-band, which shows high port isolation over a wide bandwidth. The grooved-wall horn antenna has a pair of grooves on its wall to serve as an inbuilt polarizer. By connecting the grooved-wall horn to an orthomode transducer (OMT) in such a way that the pair of grooves is aligned at ±45° with respect to the horizontal and vertical polarization of the OMT, left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) can be generated, thereby realizing a dual-CP antenna. High isolation is also achieved due to the low reflection coefficient of the horn and high isolation of the OMT. The simulated results show the proposed dual-CP antenna achieves port isolation> 30 dB over 27.4% bandwidth from 82 to 108 GHz with axial ratio (AR) < 3 dB and |S
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| < −15 dB.