Dual‐band miniaturised FSS with stable resonance frequencies of 3.4/4.9 GHz for 5G communication systems applications

Abstract

In this study, a convoluted and connecting unit structure to design a frequency selective surface (FSS) with miniaturised closely spaced dual‐bandstop is presented. Using −10 dB transmissions as the threshold for operating bandwidth, the proposed FSS possesses two stopbands with central operating frequencies of 3.4 GHz and 4.9 GHz with bandwidths of 950 MHz (2.80–3.75 GHz) and 850 MHz (4.55–5.4 GHz), respectively, and a band ratio of just 1.44. The unit dimension of the proposed FSS is 0.069λ1 × 0.069λ1, where λ1 represents the first resonant wavelength in free space. This FSS structure exhibits excellent miniaturisation properties. In addition, the proposed FSS exhibits excellent stability for both transverse electric (TE) and transverse magnetic (TM) polarisations under incident angles from 0° to 60°. Finally, the FSS sample was fabricated and measured. The simulation results are in good agreement with the measured results. The biggest innovation of this study is to use the old method to solve the new problem, that is, to realise the shielding of fifth‐generation (5G) signal by using the method of convoluted and connecting FSS. The design will be of significance in further development of 5G communications.

Miniaturized dual stop band frequency selective surface with broadband linear co to cross polarization conversion ability

“…Also the proposed FSS exhibits lower unit cell periodicity than. 25,32,33 Although unit cells in 17,[28][29][30] have miniaturized dimension but those geometries incur more design and fabrication complexity due to either convoluted pattern or dual layer metal via loaded configuration. These two reasons restrain the ease of tuning the filter response at different frequency band.…”

“…[17][18][19] Miniaturized FSS with periodic metal patches and wire mesh grids as nonresonant constituent elements for single passband first order 20 and high order 21 filter resonances are realized. Instead of single passband or stopband, FSS with multiple resonances is preferred for multifunctional situation [22][23][24][25][26][27][28][29][30][31][32][33] Single and multilayer based dual band passband FSS with first order 22,23 and third order 24 filter responses are proposed in recent years. FSS with multiple stop band resonances is needed in many applications like electromagnetic shielding to avoid interference, or as a reflector for dual band monopole or dipole antenna to improve radiation directivity.…”

“…27 Various miniaturized dual stop band FSSs with closely located frequencies based on convoluted geometry are presented in recent years. [28][29][30][31][32][33] Apart from spatial filtering of EM wave, polarization of the wave needs to modulate in different wireless applications. Traditional approaches of changing the polarization state are based on optical grating, dichroic or twisted liquid crystal results in narrow bandwidth.…”

A dual‐stopband FSS using knitted and strong‐coupled structures with excellent angular stability and polarisation insensitivity

“…In the operation of broadband antenna systems, overcoming the multi-frequency interference in the operating band has been the crucial issue. The problem is well solved by the generation of dual-band FSSs [4][5][6][7][8][9][10][11][12][13]. There are two main ways to achieve the dual-band function: one is to design each multilayer structure that works independently as in Ref.…”

Interwoven Hexagonal Frequency Selective Surface: An Application for WiFi Propagation Control

“…High values of FOM are accomplished using these types of structures, but at the cost of a significant reduction in their bandwidth. In the literature this type of structures are often used for propagation control, like electromagnetic shielding [16], electromagnetic absorbers [17], and bistate frequency selective surfaces [18].…”