Compact High-Efficiency Resonator Antennas Based on Dispersion Engineering of Even-Mode Spoof Surface Plasmon Polaritons

This article proposes a compact high-efficiency metallic resonator antenna operating at even-mode spoof surface plasmon polaritons (SSPPs). The collective electron oscillations within the structure increase the effective relative permittivity that can be tuned by engineering the dispersion of SSPP modes on the structure. The even-mode SSPPs are excited by placing a radiator at their vicinity. As an example, a resonator antenna is designed using the comb-like SSPP structure. The proposed metallic resonator antenna achieves low loss and hence high radiation efficiency because majority of fields of SSPP modes concentrates in air rather than in dielectric compared with conventional dielectric resonator antennas (DRAs). The proposed design also employs compact size due to the high effective relative permittivity and planar configuration of the SSPP resonator. A prototype was fabricated and measured. Both the simulated and measured results show the advantages of higher efficiency of 95.2% and more compact volume of 0.0002λ³ over a DRA. This method provides a good alternative for designing DRAs.