Low-profile and High-gain Dual-Linearly Polarized Offset Reflector Antenna at W-band

This paper presents a single offset-reflector antenna in a parallel plate waveguide (PPW), which is capable of radiating two orthogonal linear polarizations with high gain at W-band (75GHz-110GHz). The offset reflector is illuminated by an H-plane corrugated feeding horn placed inside the PPW. The dual-linear polarization characteristic is achieved by exploiting the two excitation modes of the over-moded PPW (OPPW), which are quasi-TEM and quasi-TE1 modes. Since the offset-reflector only collimates the beam in one plane, the directivity is further improved by 6dB by flaring the aperture along the orthogonal plane. The antenna shows a peak gain of 26dBi at 90GHz and more than 30% bandwidth for both polarizations with a sidelobe level below -18dB over the entire operating frequency band.