Double Sided Wideband Concentric Ring Spatial Filters for Mid-Band 5G Devices

Abstract

This paper presents the methodology, development, and implementation of the double concentric ring band-pass frequency selective surface (FSS) based spatial filters. The filters are designed to improve the active responses of the 5G antennas by incorporating them as superstrate or as substrates. A comparable circuit model is used to anticipate the resonant frequency bands required for predicting the FSS band-pass behavior. The designed spatial filter is composed of a combination of periodic circular loop structures engraved on both sides of a thin dielectric substrate. The proposed design of a double circular loop FSS exhibits band-pass characteristics for n77, n78, and n79 bands of the mid-band 5G spectrum (ranging from 3 GHz - 6 GHz) and provides insensitivity to polarization angles of the incident plane wave. The computed, simulated, and measured findings are all depicting a similar pattern that validates our structure.