Passive approaches for improvement of TX to RX antenna isolation in millimeter wave repeaters

Two passive techniques for improving the isolation between transmitting (TX) and receiving (RX) antennas in V/W-band repeaters are presented. Specifically, corrugations and 2-D array of grounded circular patches are designed to provide a reactive impedance surface (RIS) between the antennas. It is found, that both approaches enhance the isolation by ~20 dB compared to the basic case when TX and RX antennas are recessed in a smooth, untreated ground plane. Computational studies are experimentally validated with 3D printed horns fed with a novel 45-110GHz ridge waveguide line.