A high-performance dual-polarized corrugated horn for a compact antenna test range system

A high-performance dual-polarized horn antenna for a 5G millimeter wave compact antenna test range system (CATR) is proposed in this article. The feed antenna is mainly composed of a double-ridged waveguide junction orthomode transducer (OMT), mode converter, and corrugated horn antenna. Among them, the OMT is the key device for the feed antenna to achieve dual polarization characteristics, and adopts a modular design method to apply the multi-section impedance transformer in the vertical and horizontal polarization channels with good transmission characteristics. The corrugated horn antenna generates a symmetrical radiation pattern mainly in six corrugated slots. The proposed dual-polarized corrugated horn antenna impedance matching bandwidth (VSWR < 2) is 24-50 GHz. Moreover, the measured gain is 10-12 dBi, and the measured cross-polarization level is less than -30 dB within the operating frequency range. Meanwhile, the half-power beamwidth radiation pattern in the whole operating band has a good symmetry and the beamwidth in both E- and H-plane remains stable. As a practical application, the designed antenna is used as the feed of the CATR system. The measured results show that the amplitude distribution in the quiet zone (QZ) is within +/- 1 dB, the phase distribution is within +/- 8 degrees, and the cross-polarization isolation is better than 27 dB. The performance of the QZ is conducive to the use of the CATR system.