A compact wearable antenna operating at 2.45 GHz with a novel Electromagnetic Band Gap (EBG) structure as a reflector is proposed. The broadband monopole is used as the main radiator of the antenna, and the gradient feeder structure and etched slot on the ground are used to adjust the matching effect of the antenna port. The current path is extended, and the structure is made more compact by slotting the surface of the EBG cell. Then, a 3 x 3 EBG reflector is constructed and loaded to the bottom of the antenna to improve the antenna gain performance and reduces the specific absorptivity (SAR). A three-layer human model (skin-fat-muscle) has been built in High Frequency Structure Simulator (HFSS) to analyse the influence of human tissue on the wearable antenna system. Combined with the practical application background, the radiation performance of the system under bending is also explored. The simulation results show that the application of EBG reflector can increase the antenna gain by about 4.77 dBi and the front-to-back ratio by 17dB, reduce SAR by more than 95%, and the overall size of the system is only 60.3 x 60.3 x 3.5 mm3 (0.49λ). The antenna system has the characteristics of simple structure, small size, high gain, and low SAR value, which is of certain reference value for the research on the wearable antenna.
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