Design of a Bandpass Frequency-selective Metasurface Structure

In this paper, we designed a frequency selection surface with bandpass characteristics, which is suitable for antenna filtering and stealth function in space. The designed frequency selective absorber (FSA) structure consists of upper and lower layers, both of which can realize nearly transparent wave-transparent band in antenna operating band 12 GHz, and the lower layer of frequency selective surface (FSS) is designed to realize reflections in the surrounding band, so that the incident wave will be secondary absorbed by the upper FSA after reflections. After reflection, the energy of the incident wave will be absorbed by the upper FSA. The designed bandpass frequency selective surface at 11.57GHz-13.50GHz can realize the normal radiation of the applicable antenna in the working band, and the frequency selective absorber (FSA) can realize the absorption of the incident electromagnetic wave of two polarizations outside the antenna’s working band (5.01GHz-10.74GHz and 15.25GHz-16.76GHz) to achieve the single-site and dual-site operation outside the working band of the antenna. single-site and dual-site RCS reduction outside the operating band. For working antennas applying this type of super-surface, the gain of the antenna is not affected because the radiated wave energy is not reflected or absorbed by the designed super-surface.