  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.
