Design and demonstration of a 2.5D frequency‐selective surface for sub‐6 GHz 5G wireless communication

Abstract

This paper presents an ultraminiaturized bandstop closed‐loop 2.5D frequency‐selective surface (FSS) for sub‐6 GHz 5G wireless communication. Four metallic vertical vias interconnect metallic elements present on both sides of the substrate to form a modified closed‐loop design. The proposed structure band stops the entire sub‐6 GHz 5G band (C‐band/NR N78 band/LTE 42/43 band) ranging from 3.2 to 3.9 GHz with a resonant notch at 3.62 GHz. This design supports polarization insensitivity and procures maximum relative deviation of 0.5% and 0.2% at 80°incident transverse electric (TE) and transverse magnetic (TM) polarized waves, respectively. The proposed FSS prototype has been fabricated and tested. Experimentally, the resonant notch is obtained at 3.55 and 3.68 GHz under TE and TM normal incident polarized waves, respectively. Moreover, good agreement in the frequency response curves is observed between simulated and measured results. The proposed unit cell is 3.6 × 3.6 mm2 in dimensions, which is 0.04λ × 0.04λ, where λ is the resonant wavelength.

Ultrathin and conformal frequency selective surfaces bandpass filter to eliminate the 5G bands on radio altimeters

“…14,15 The angular stability is better in the FSS layout presented in the literature but it is a bulkier multilayer design. 16 FSS presented in works, 6,17 have stable frequency response with respect to varying angle of incidence, but the unit cell involves a via-based interlink between layers which increases fabrication complexity. The substrate used for the proposed FSS should be a cost-effective solution, as compared with the Rogers RT Duroid substrates used in existing works.…”

“…FSS structures have bandpass and bandstop capabilities 3 ; and these structures are in 2D, 2.5D, or 3D form. [4][5][6] FSS layouts are used as spatial filters [7][8][9] ; to provide phase shift in transmitarray antennas 10,11 ; and incorporate stealth in military/domestic communication systems. 12,13 The stability of FSSs frequency response for various incident and conformal angle are notable performance metrics.…”

“…An approach for selective filtering would be to use frequency selective surfaces (FSS), which can be wrapped on existing RAs. FSS structures have bandpass and bandstop capabilities 3 ; and these structures are in 2D, 2.5D, or 3D form 4–6 . FSS layouts are used as spatial filters 7–9 ; to provide phase shift in transmitarray antennas 10,11 ; and incorporate stealth in military/domestic communication systems 12,13 .…”

Triple band frequency selective surface design for 5G mm‐wave communication with artificial neural networks

“…It operates as a radiator at the S‐band and as a spatial filter at the K‐band. A compact, triple band notched FSS is presented for ultra‐wide‐band (UWB) frequency range 15 . Triple band notches are obtained at WiMAX and satellite communication downlink C‐band (3.3–4.2 GHz), WLAN (5.1–5.9 GHz), and satellite communication X‐band (7.2–8.4 GHz) for both TE and TM polarizations.…”

Design of 2.5-D miniaturized frequency selective surface with enhanced oblique stability

“…Furthermore, miniaturization also improves the angular stability under oblique incidence. Due to these attributes of miniaturization, various 2-D, 2.5-D and 3-D structures have been presented in the literature [23][24][25][26][27][28][29][30][31] .…”