Circularly Polarized Wearable Antenna Based on AMC Structure for WBAN Applications

In this work, a circularly polarized wearable antenna with integrated artificial magnetic conductor (AMC) is proposed for wireless body area network (WBAN) applications. The presented radiator is implemented on a two-layer felt substrate. It comprises an asymmetric monopole suspended over a 5×5 AMC structure. The circular polarization is obtained-while maintaining simple design-by incorporation of L-shaped monopole, asymmetric CPW-based ground and parasitic patches. Note that AMC does not introduce polarization rotation. Instead, it improves antenna gain while reducing specific absorption rate. The EM simulation results indicate that bandwidth in terms of impedance and 3 dB axial ratio (AR) correspond to 23.2% (i.e., from 3.16 GHz to 3.99 GHz) and 13.7% (i.e., from 3.4 GHz to 3.9 GHz) with a peak gain of 8.62 dBic. Furthermore, the obtained maximum specific absorption rate is only 0.4W/kg for 1g of human tissue mass, i.e., much below the threshold imposed by the international safety standard.