Miniaturized textile flexible antenna with electromagnetic band gap for wearable application

A miniaturized all-textile wearable antenna based on the Electromagnetic Band Gap (EBG) is proposed for the ISM (2.40-2.48 GHz) band. The denim fabric is used as the substrate of the antenna ensuring the comfortability. To reduce the Specific Absorption Rate (SAR), a "*" shaped miniaturized EBG array with identical fabric is introduced and the size is decreased by corner-cutting at the end of slits. After loading the EBG, the gain is increased by 4 dBi, and the front-to-back ratio (FBR) is improved by about 9 dB. Moreover, the overall size of the antenna is 48 x 54 x 3 mm(3), reduced by 37 %. The bandwidth and radiation characteristics in free space are measured in various scenarios such as planar, different bending directions and degrees, all of which can meet the wearable requirements. The SAR is characterized by calculating the electromagnetic field distribution in the human tissue model. The results show that the SAR can reach 0.34 W/kg (1 g/cm(3)), a decrease of 93 %.