Performance evaluation of compact FSS‐integrated flexible monopole antenna for body area communication applications

Abstract

Summary This article presents a compact wearable antenna integrated with a novel frequency selective surface (FSS) made of textile materials. The antenna can be applied in wearable health monitoring applications aimed at the 2.45‐GHz Industrial Scientific and Medical (ISM) band. An array of 4 × 4 octagonal slot‐shaped FSS (106 × 106 mm2) superstrate enhances the performance of the modified Koch curve planar monopole antenna (44.85 × 39 mm2). The Jeans substrate prototype with the overall dimensions of 1.128λ0 × 1.128λ0 × 0.319λ0 covers the bandwidth of 2.45‐GHz ISM band from 2.24 to 2.76 GHz (S11 ≤ −10 dB). The band rejection and reflective nature of the proposed FSS suppress the back radiation and improves the antenna's gain by −20 dB and 6.3 dBi, respectively. The specific absorption rate (SAR) level is reduced to 0.445 W/kg from 24.995 W/kg with a higher reduction rate of 98.21%. Many literature reports produced higher gain and lower SAR but exhibited reduced efficiency when the antenna is placed near the human body. The wearable antenna's frequency response tends to vary under bending conditions for narrowband antennas. Wide‐band monopole antennas produce omnidirectional radiation pattern which tends to affect human body tissues. So stable polarization‐insensitive FSS is placed behind the antenna to enhance the antenna's gain and avoid back radiation. The proposed antenna exhibits stable performance under bending conditions with fractional bandwidth of 22.2%, gain of 8.83 dBi, and produces a better efficiency of 91.30% when the antenna is positioned in the vicinity with human body models. The experimental validation shows that the proposed antenna is a promising candidate for wireless body area networks.

Screen‐printed dual‐band wearable textile antenna incorporated with EBG structure for WBAN communications

“…13 However, the shorting pins and SIW vias provide fabrication complexity in textile substrates. In Sugumaran et al, 14 Koch curve type, CPW-fed monopole wearable antenna with frequency selective surface (FSS) is developed on the jean substrate to radiate at 2.45 GHz. The distance between FSS and the antenna is (λ/4) 28 mm, which increases the antenna thickness.…”

A Dual-Band Low SAR Microstrip Patch Antenna with Jean Substrate for WBAN Applications

“…As is well known, the monopole, dipole, and slot antennas have backward radiations, which yield the SAR value exceeding the standard. Hence, the reflector should be placed behind these antennas in order to reduce the backward radiations toward human body [11][12][13]. In [14], the dual-band T-shaped monopole antenna was proposed.…”

Design and performance analysis of 8‐port multi‐service quad‐band MIMO antenna for automotive communication

“…A dual band eight port antenna proposed in Reference 36 uses a rectangular shaped DGS for 5G services and a fractal curved radiating element with 4 port MIMO antenna is proposed in Reference 37, where composite right/left hand element is placed in the ground plane to suppress the surface current to improve the isolation between the elements. An ISM band of single element Koch curve modified antenna is introduced in Reference 38 with high gain of 6.3 dBi using frequency selective surface.…”