Flexible Microwave Devices and Dual-frequency-scanning Antenna Based on Spoof Surface Plasmon Polaritons

In this paper, several spoof surface plasmon polaritons (SSPPs) microwave devices and antenna proposed by our group are summarized. Firstly, a flexible wideband power divider with high isolation incorporating spoof surface plasmon polaritons with graphene flake is demonstrated. The power divider is implemented on planar SSPPs structure with a piece of graphene flake as an isolation resistor, showing excellent performance under bent and twisted state. Secondly, an ultrathin and flexible directional coupler with arbitrary coupling level using S-shape spoof surface plasmon polaritons coupled-line is introduced Using the coupling effect between two identical ultrathin S-shape plasmonic waveguides, the presented ultrathin directional coupler possesses excellent flexibility, arbitrary coupling level, alternative working band and wide bandwidth. Finally, a dual-frequency-scanning broadband antenna based on Z-shape spoof surface plasmon polaritons is presented by utilizing Z-shape SSPPs structure and circular patch arrays. The simulation and measured result exhibit that the dual-frequency-scanning SSPPs antenna can offer two wide operating frequency bands and large beam scanning angle with both operating bands.