A wearable RFID sensor and effects of human body proximity

Wearable electronics integrate smart sensors and compact computing systems into garments. In this paper, we discuss the design and simulation of a knitted textile RFID sensor for wearable applications. The sensor comprises a textile folded dipole antenna, specifically designed for use with an inductively-coupled RFID microchip at 870 MHz. As opposed to conventional microchips, in this case the device does not need any physical soldering, making it very convenient for wearable applications. The numerical analysis was extended to evaluate the loading effects of human body proximity. For distances greater than 10 mm, the antenna maintains good impedance matching and a broadside radiation with moderate gain.