3-D dual-polarized bandpass frequency selective surface with quasi-elliptic response based on rectangular waveguide cavity

Abstract

A new three-dimensional (3-D) frequency selective surface (FSS) based on rectangular waveguide cavities is presented, which realizes a quasi-elliptic bandpass response by multiple transmission zeros/poles. Each unit cell of the proposed FSS is composed of an empty rectangular waveguide cavity and a cuboid circuit board with two back-to-back square loops. With the help of the rectangular waveguide cavities, the electrical and magnetic coupling paths are constructed, resulting in two transmission poles. The constructed out-of-phase signal paths cause two transmission zeros in the upper stopband. To explain the operating principle of the proposed FSS, an equivalent circuit model is given and analyzed using the odd-and even-mode method. A prototype of the proposed FSS is fabricated and measured. The measured results agree well with the simulated results, and show that the FSS can achieve a stable response to variations of incident angle from 0°to 60°for both TE and TM polarizations with wide out-of-band rejection. In addition, the proposed design also realizes a relatively small unit cell.

Low‐profile frequency selective surface with quasi‐elliptical bandpass response using antenna‐filter‐antenna approach

“…The 3‐D FSS proposed in 20 is based on a simple square coaxial waveguide and utilizes vias, H‐shaped slots, and center gaps in a single unit to introduce more resonances and couplings, resulting in multiple transmission zeros/poles. In Yu et al 21 the electrical and magnetic coupling paths are constructed with the help of the rectangular waveguide cavities, resulting in two transmission poles. Different from the above 3‐D FSSs, the 3‐D structure proposed in Wang et al 22 is composed of three layers of metallic patches connected by vertical wires.…”

Design of frequency selective rasorber with high in-band transmission and wideband absorption properties

“…Frequency selective surface (FSS) is a kind of periodic structure composed of the metallic patches or aperture elements of arbitrary geometries [1,2,3]. In the past, due to its frequency selective properties, FSSs have been widely used to construct hybrid radomes [4,5], spatial filters [6,7,8], and absorbers [9,10,11]. For the conventional FSS-based radomes, the out of band incoming electromagnetic (EM) waves would be reflected towards an unthreatening direction to reduce the radar cross section (RCS) of the antenna system.…”