Design of a w-band dual-polarized monopulse cassegrain antenna feed by five-unit horns

A W-band dual-polarized monopulse Cassegrain antenna feed by five unit horns is presented, which combines one dual-polarized transmit-receive SUM channel and two single-polarized 2-dimensional DIFF receiving channels. The dual-polarized function of the transmit-receive SUM channel is realized by a ortho-mode transducer(OMT) without thin films. At 94 GHz, the SUM beam gain over 38.25 dBi and the aperture efficiency of 41.5% are achieved. The first sidelobe level of SUM beam isunder -24 dB and the gain ratio between the SUM and DIFF beams is 4.8 dB. Simulated results demonstrate that the proposed antenna is a promising candidate for W-band dual-polarization antennas with high aperture effciency, low side-lobe level and good performance of monopulse.