Wide-Angle Frequency Beam Scanning Antenna Based on the Higher-Order Modes of Spoof Surface Plasmon Polariton

A wide-angle frequency beam scanning antenna based on spoof surface plasmon polaritons (SSPPs) is proposed for planar-integrated communication circuits. The SSPP-based antenna is constructed by hole arrays etched on the standard $50~\Omega $ coplanar waveguide, which can achieve ultrawide bandwidth and wide-angle beam scanning from backward direction to forward direction as the frequency changes. The radiation mechanisms of the SSPP-based antenna are based on the higher-order modes of the structure, which have been analyzed by the dispersion curves and electric field distributions. The overall width of the proposed SSPP-based antenna is only $0.95\lambda _{0}$ (with $\lambda _{0}$ being the wavelength of the lowest working frequency). The simulated results show that the proposed frequency beam scanning antenna achieves a wide scanning angle of 129° over a frequency range from 11.7 to 50 GHz (for $\vert S_{11}\vert dB) with an average gain level of 12.38 dBi. The good agreements between the simulated and measured results validate the proposed design.