Metasurface Instrumented High Gain and Low RCS X-Band Circularly Polarized MIMO Antenna for IoT Over Satellite Application

In this article, an X-band metasurface is designed and this metasurface array is used as an instrument to increase gain & reduce radar cross section of circularly polarized X-band MIMO antenna through super-state and under-state positioning of array respectively. Absorbance of the metasurface to the intended frequency band (i.e., 6.75GHz-14.0GHz) is more than 90.0%. Metasurface is designed on FR-4 substrate height (H_s) 3.1mm with unit cell dimension of 7.95×7.95×3.1mm³ (0.265λ_o×0.265λ_o×0.103λ_o) at 10GHz. The proposed antenna is also designed on FR-4 substrate with dimensions of 29×23×1.6mm³ (0.966λ_o×0.766λ_o×0.0.053λ_o) at 10GHz. The super-state and under-state positioning of metasurface array over MIMO antenna is increased the gain (peak gain 12.6dBi at 11GHz) and reduced the mono-static RCS (18dBm²) across the band respectively. The characteristic of the antenna is likewise verified by its s-parameters, radiating efficiency, gain and diversity parameters for the intended band. The simulated & measured results are having better harmony which exhibits suitability of the proposed designs for IoT over satellite, military application, and also useful to identify blood clouting in CT-scan application.