Bandenna for RF energy harvesting and flexible electronics

A flexible antenna for portable and wearable radio frequency energy harvesting and flexible electronics applications is proposed. A silicone wristband with ɛ r = 3 is used as the substrate to support the radiating element and hence the appellation given as bandenna – a wristband antenna. The radiating element is a single fed corner truncated circularly polarized microstrip patch operating in the 2.45 GHz ISM band. The measured results show that for VSWR bandwidth is 100 MHz from 2.4 to 2.5 GHz. The proposed bandenna is right handed circularly polarized with 3 dB axial ratio bandwidth of 25 MHz. It has a directional radiation with stable gain of greater than 5 dBi over the VSWR bandwidth. The proposed bandenna is cost effective as it exploits commercially available silicone and ensures reduced SAR due to the large ground plane backing the radiator. The bandenna in combination with a rectification unit can be worn as wristbands to serve as ambient radio frequency energy harvester. The proposed bandenna being flexible can support wireless communication when integrated into future flexible electronic devices.