Electronically Controlled Beam-Scanning Antenna Based on Spoof Surface Plasma Polaritons

This paper proposes an electronically controlled beam-scanning antenna using planar spoof surface plasma polaritons (SSPPs). The antenna consists of periodically arranged elliptical metallic patches on one side of an H-shaped planar waveguide. The dispersion unit of the SSPPs scanning antenna includes H-shaped dispersion structures with different periods and elliptical radiating patches. By exploiting phase discrepancies between SPP waveguides feeding the elliptical patches at different frequencies, the antenna achieves wide-angle scanning from near-endfire to the forward direction. Varactor diodes are integrated into the periodic H-shaped dispersive structure to provide reconfigurable surface impedance, resulting in an electronically controlled beam-scanning SSPPs antenna. The results demonstrate a frequency beam-scanning capability of 128° (-90° to +38°) within the 4.0-7.0 GHz range. Additionally, the antenna achieves fixed-frequency beam-scanning of over 30° within a limited control range.