Koch Fractal Based Wearable Antenna Backed with EBG Plane

A low-profile Koch modified monopole antenna backed with EBG plane has been proposed in this work for wearable applications of MBAN band (2.36–2.40 GHz) standards. The designed EBG-antenna is composed of a triangular-shaped microstrip antenna as a radiator and a 2 x 2 square-shaped EBG plane as a reflector to improve the isolation between the antenna and human body tissues. The free-space analysis of proposed antenna shows that it has an overall impedance bandwidth of 50 MHz centered at 2.38 GHz, a gain of 7.8 dBi and a radiated efficiency of 86%. For detailed on-body analysis and SAR evaluation of proposed design, it is tested on a 150 x 150 mm2-phantom composed of skin, fat, muscle and bone. The results show that the return loss and radiation characteristics of EBG-antenna remain unchanged to the loading of human body tissues with an extremely low SAR values below 0.4 W/kg and 0.7 W/kg for 10g and 1g of biological tissues with a separation of 0 mm between antenna and phantom. Thus, the designed wearable antenna topology is a prime candidate for both on and off-body communications devices.