A novel FSS based on hybrid boundary condition cavity

In this paper, we present a novel bandpass frequency selective surface (FSS) with low passband insertion loss and good frequency selectivity. Each periodic cell consists of a special cavity with hybrid perfect electric conductor (PEC) and perfect magnetic conductor (PMC) boundary conditions, which are formed by four common metallic vias and the complementary slots etched on both top and bottom surfaces. By using approximated method, the novel cavity is numerically investigated and the frequencies of the main resonant modes are obtained. It is found that a two-pole pass band with sharp roll-off can be achieved due to the proper combination of the cavity and slots. The frequency response of the proposed FSS is also demonstrated and shows its insensitivity to incident angles and polarization etc.