Ultrawideband Energy-Selective Structure Based on Spoof Surface Plasmon Polariton

A ultrawideband energy-selective structure (ESS) is proposed in this letter that can perform adaptive strong electromagnetic environment shielding. The adjustable dispersion curve of the spoof surface plasmon polariton (SSPP) unit with loaded nonlinear devices is utilized to achieve the transition between transmission state and shielding state based on the incident electromagnetic wave power intensity. The full wave simulation results conducted in waveguide WR-137 show that the structure can achieve insertion loss of less than 1 dB in the ultrawideband range of 6.7 GHz to 10.8 GHz (46.9% relative bandwidth), while achieving shielding efficiency of over 10 dB under signals with high power density. The prototype was simulated, fabricated, and measured through waveguide injection experiments. Considering the limited size of the waveguide structure, part of operating frequency bands have been verified. The SSPP-based ESS design method with ultrawideband characteristic has enormous application potential in electromagnetic shielding of electronic equipment.