Complementary frequency selective surface pair-based intelligent spatial filters for 5G wireless systems

Abstract

Frequency selective surface (FSS)-based intelligent spatial filters are capturing the eyes of the researchers by offering a dynamic behavior when exposed to the electromagnetic radiations. In this manuscript, a concept of creating complementary structures which stems from Babinet’s principle is illustrated. A hybrid complementary pair of FSS (CPFSS) comprising double square loop FSS (DSLFSS) and double square slot FSS (DSSFSS) on either side of the dielectric substrate is proposed. DSLFSS offers band-pass behavior and can be placed as a superstrate, whereas DSSFSS behaves as a band-stop intelligent spatial filter that blocks the radiations falling on it, thus making them applicable for use as a substrate. The technique utilized for analyzing DSLFSS and DSSFSS structures is based on the equivalent circuit modeling and transmission line methodology. The CPFSS structure offers the design simplicity, hence, suitable for placing them with the printed patch antenna radiators in wireless networking devices operating in sub-6 GHz 5G spectrum. DSLFSS offers band-pass behavior ranging from 2.99 to 5.56 GHz, whereas DSSFSS offers band-stop behavior ranging from 2.85 to 5.42 GHz covering all n77 (3.3–4.2 GHz), n78 (3.3–3.8 GHz), and n79 (4.4–5 GHz) bands of FR1 spectrum of sub-6 GHz 5G range. The passband and the stopband offered by the two structures of CPFSS geometry are stable to oblique angles of incidence and the proposed design also offers polarization-independent behavior. The thickness of the dielectric region existing within the pair of designed structures is critical for the location of the passbands and the stopbands. The impact of the overall thickness of the dielectric substrate on the passbands and stopbands is also reported in this article.

Influence of Flexible and Textile Substrates on Frequency-Selective Surfaces (FSS)

“…Structures containing a square or circular shape in the border are often used in the design of multimode FSSs [ 3 , 34 , 35 ]. The purpose of this paper was to compare structures fabricated on a textile substrate to analogous structures designed and fabricated on rigid FR4 substrates reported in the literature [ 27 ].…”

Modelling of Wideband Concentric Ring Frequency Selective Surface for�G燚evices

“…These filters include a built-in frequency selection that improves the radiation performance of a radiator. Frequency selective surfaces (FSS) have attracted a lot of attention in recent years as a method of constructing spatial filters because they may impart filtering features in the spatial domain [1][2][3][4][5]. Recent study has sought to build and promote a square shaped loop, circumferential ring, ellipsoid, hexagonal geometry, and a cross dipole as geometric patterns that might be employed in the electromagnetic spectrum [6][7][8].…”

A dual‐band complementary frequency selective surface combining structures that provides narrow and wide stop‐band frequency responses

“…Munk 7 shows that the square loop with the grid has good angular stability, while the crossed dipole does not. Thus, we propose to combine these geometries in one layer complementary frequency selective surface (CFSS), as this type of structure presents good angular stability 8‐11 . Our structure presents a narrow and a wide rejection band, with simple geometries, low profile, angular stability, and polarization independence.…”