Split ring resonator antenna system with implantable and wearable parts for far field readable backscattering implants

We present a spatially distributed split ring resonator (SRR) antenna system comprising a small implanted split ring resonator carrying a UHF RFID microsystem and a wearable split ring. In the wireless experiments, the backscatter response of the microsystem is detectable at a distance of 1 m within the entire UHF RFID band from 840 to 960 MHz when the implant depth is 10 mm or less. Moreover, its working distance remains higher than 90 cm under marked, up to 5 mm later or 30° rotational, misalignment between the implanted and wearable parts.