Epidermal UWB RFID Tag for Application On-Skin

UHF RFID tags have been demonstrated as transfer tattoos on-skin [1]. However, the performance of these designs are limited owing to their very close proximity to highly lossy tissues which makes them unsuited for application in dense environments required in many sensitive tracking and identification applications, because of the inherent high power narrow band requirements of UHF RFID. Conversely, many proposed high resolution internal location systems use Impulse Radio Ultra-Wideband (IR-UWB) transmission with narrow RF pulses of a few hundred picoseconds spread over several GHz of bandwidth and with a power spectral density in the noise floor. These low spectral power density pulses are very difficult to detect and almost invisible to unauthorized readers as UWB pulses are indistinguishable from the noise, and can be detected only by receivers using correlation [2]. UWB RFID tags have been shown in location systems to offer fine temporal and spatial resolution, with cm level accuracy in both outdoor and indoor localization in all three dimensions [3].