Three-Dimensional Fully Metallic Dual-Polarization Frequency-Selective Surface Design Using Coupled-Resonator Circuit Information

This work employs a new approach to analyze coupled-resonator circuits to design and manufacture a fully metallic dual-polarization frequency-selective surface (FSS). The proposed filtering structure is composed of a series of unit cells with resonators fundamentally coupled along the z-direction and then repeated periodically in the xy-plane. The fully metallic cascaded unit cell is rigorously analyzed within an infinite periodic environment as a coupled-resonator electromagnetic (EM) circuit. The convenient design of the EM resonators makes it possible to push the evanescent EM field through the metallic structure in the desired frequency band for both polarizations. An FSS prototype is manufactured and measured, and good agreement is found between the simulation results and the final prototype.