A Wideband Circularly Polarized All Textile on Body Antenna for Defense Applications

A compact low-profile circularly polarized wearable conformal antenna based on metasurface operating in X-band is proposed for defense application. The emphasis of this brief is on additional resonances generated by propagation of surface wave on modified metasurface (MS) which offers wide impedance bandwidth (IBW) with high gain and wider axial ratio bandwidth (ARBW). The proposed antenna is flexible & perfectly conforms to the human body due to the use of cordura fabrics as the substrate & copper conductive tape as the conductor, enabling the antenna to be incorporated inside clothing and suitable for defense application. For experimental validation, the prototype is fabricated with the dimensions of
$0.76\times 0.76\times 0.04\,\,\lambda ^{3}$
. The measured outcomes indicate that a wide IBW of 37.5% (7.73–11.3 GHz), a half-power beam width of 62°, high gain of 8.9 dBic, and a 3-dB ARBW of 21.3% (8.8–10.9GHz) are achieved. Furthermore, it has been demonstrated that the antenna performance is stable during structure-deformation (conformal) on a cylindrical surface and human body loading. The specific absorption rate (SAR) is much lower than the U.S. standard of 1.6 W/kg & EU-standard of 2W/kg with good radiation characteristics, the proposed design antenna suggests a promising candidate for defense application.