Characterization of RF Propagation in Muscle Tissue for Passive UHF RFID Tags



In this paper, we present an analytical analysis and study of the propagation of radio frequency (RF) energy in muscle tissue. The workings of passive UHF RFID tag backscatter are studied. Backscatter field strength propagation models are used to describe the skin effect on muscle tissues. Energy dissipation and field intensities are studied for humans and larger vertebrates using a modified Friis propagation model for passive tag backscatter. An analytical evaluation is conducted for the electric field in muscle tissues for near-field distances. It is shown that the maximum electric field inside a sphere of muscle tissue for a typical passive UHF RFID tag with a loaded meander tag antenna is less than 70dBV/m, which is more than two orders of magnitude lesser than the limits for safe exposure to RF energy produced by mobile devices, as adopted by the Federal Communications Commission (FCC).


Available from: Daniel Engels, Dec 14, 2013