An Ultra-Wide Stopband Spoof Surface Plasmon Polaritons Strip for Shared-Aperture Base Station Antenna Applications

A spoof surface plasmon polaritons (SSPPs) strip with ultra-wide stopband and low-pass characteristics is proposed for the shared-aperture base station antennas. The SSPPs strip unit comprises two transmission line segments and a shunt-loaded open-circuited stub. Initial parameters of the SSPPs strip unit are computed through an equivalent circuit analysis. Subsequently, simulation software is employed to derive the dispersion characteristics of the SSPPs strip, aiding in the determination of its specific dimensions. Leveraging the gradient branches of port matching, we achieve an SSPPs strip featuring a stopband spanning 1.9-3.9 GHz and a passband from 0.69-0.96 GHz. Endowed with an ultra-wide stopband and low-pass attributes, this SSPPs strip exhibits considerable potential for applications in shared-aperture base station antennas.