Wideband Circularly Polarized Antenna With All-Textile Metasurface for Off-Body Communications

Abstract

A novel wideband circularly polarized (CP) antenna with all-textile Metasurface (MS) is investigated for wearable devices. The proposed antenna is composed of a microstrip patch antenna (MPA), on which a tilt slot is etched for realizing CP radiation. A piece of MS is placed right above the MPA, achieving broadband performance. Specifically, the bandwidth broadening mechanism is revealed using the characteristic mode analysis. The simulated −10-dB bandwidth is 34.7% (4.65-6.56 GHz) and the 3-dB axial ratio is 22.4% (4.75-5.98 GHz) with a peak gain of 9.0 dBi as the antenna is attached to a multilayer human tissue model. In addition, the front-to-back ratio of the antenna is greater than 25 dB, which is suitable for off-body communications.