Two-Port, Common Aperture, High-Isolation, Dual-Polarized Sub-Millimeterwave Antenna System Based on Spatial Power Divider

A two-port antenna system is proposed that uses a polarization-independent spatial power divider to align the beams from two orthogonally oriented dual-polarized feeds. Such an antenna system will provide a common aperture for transmit and receive, and high port isolation, while minimizing radar parallax and maintaining compatibility with fully polarimetric radar. The spatial power divider is designed using an all-dielectric metasurface approach, and is fabricated on a silicon wafer using the standard micromachining technology. The simulated device exhibits at most 0.1 dB of difference between reflection and transmission for both TE and TM incident waves at 45-degree incidence, over a band from 227 GHz to 239 GHz.