Simultaneous Transmit-Receive Horn Antenna Based on a Nonreciprocal Metasurface with Embedded Magnetic Bias

Many simultaneous transmit and receive (STAR) antenna systems require a ferrite circulator to separate transmitted and received signals. However, conventional ferrite circulators exhibit drawbacks, such as large size and limited isolation. This paper introduces an X-band STAR antenna consisting of a horn antenna integrated with a novel passive metasurface that exhibits Faraday rotation. The metasurface is composed of a yttrium iron garnet (YIG) wafer with embedded neodymium magnets that are held together by dielectric substrates. The substrates provide impedance matching and extend the operational bandwidth. The metasurface, with embedded magnets, is mounted to the horn’s aperture. The proposed antenna is described in detail, including its operating principle, design, and simulated performance.