Search

A third-order dual-polarized elliptic wide passband Frequency Selective Surface (FSS) has been proposed in this article. The unit cell is comprised of Y-shaped fractal geometry integration on the tri-pole and evolved as the stub-loaded tri-pole (SLTP) structure on an ultra-thin FR-4 substrate (ϵr = 4.4). The novel back-to-back cascading approach of the aforesaid proposed design array with optimized air spacer enhances electromagnetic coupling, resulting in maximally flat and substantially wider third-order bandpass filtering capability. −3 dB passband filtering performance (8.3–20.1 GHz) and −1 dB transmission characteristics (8.9–19.8 GHz) encompass the X and Ku band spectral ranges. The elliptical transmission coefficient leads to a remarkable passband selectivity factor (SF = 0.91). Equivalent circuit models (ECM) have been mapped, and the prototype has been experimentally validated. Angular stability (θ ≤ 40°) for both TE and TM polarizations ensures the employability of the proposed FSS for the radome. [ABSTRACT FROM AUTHOR]

A miniaturized and flexible frequency-selective surface (FSS) has been presented in this article with a unit cell size of 0.049 λc × 0.049 λc where λc is the free space wavelength at the lower cut-off frequency. In order to achieve an ultra-wide (−3 dB) second order pass band of 151.3% with enhanced selectivity factor of 0.887, a cascaded triple layered hybrid resonating structure has been proposed with symmetrical Minkowski island-shaped fractal geometry pair and spiral-shaped middle layer in optimized air gap coupling. Furthermore, 149.8% ultra-wide pass band also ascertains the conformal feature of the proposed structure. In addition to this, the proposed FSS provides the stable angular response for both TE and TM polarization. An equivalent circuit model has been synthesized for accurate frequency response. Finally, a sample prototype has been fabricated to verify the experimental validation. Excellent angular stability under large oblique incident and significant conformal characteristics ensure the compatibility of the proposed structure for electromagnetic stealth in 0.9–1.8 GHz GSM band, 2.10–2.14 GHz wireless medical telemetry band, 2.4–2.5 and 4.9–5.8 GHz WLAN band, 3.4–3.7 and 4.4–4.9 GHz sub-6 GHz 5 G band, and 3.7–4.2 GHz C band. [ABSTRACT FROM AUTHOR]

This paper presents a compact single feed circularly polarized (CP) antenna along with a frequency selective surface (FSS) that acts as a partially reflective surface over the patch. Patch is loaded with four diagonally asymmetric complementary split ring resonators (CSRRs) in order to achieve circular polarization. In this paper a novel design of reflective type FSS layer is presented at 2.4GHz. The size of FSS unit cell is approximately 0.132λ0 × 0.132λ0, and it is placed at a distance of 0.146λ0 from the patch. Simulated impedance bandwidth of the antenna for S11 < -10 dB is from 2.385 to 2.506 GHz (121 MHz or 4.95%) which covers the entire IEEE 802.11 WLAN band (2.4-2.484 GHz). Position of the four CSRRs on the patch and the height of FSS screen are determined through parametric studies, and the detailed analyses in terms of reflection coefficient, axial ratio, and gain variation are also presented. Gain of the antenna is 3.02 dBic at the operating frequency 2.45GHz. Measured results are in good agreement with the simulated ones. [ABSTRACT FROM AUTHOR]