Updated August 2021.
Radio Frequency Identification is the use of radio communication to identify an object. Early work dates back to the 1930's. More recently, folks have developed passive tags -- tags with no battery -- that operate in the ultra-high-frequency (UHF) bands. Our tutorial covers the UHF physical layer -- the radio waves and how they get from reader to tag and back. The book has a much more detailed discussion of these issues. We also provide a brief report describing interception of the backscattered signal from a UHF tag, just in case you thought it couldn't be done.
Cooperative Tag Communications (a fully animated version of the paper presented at the RFID Technology and Applications Conference in Tokyo, September 2015)
Tutorial: UHF RFID Physical Layer
Intercepting an 18000-6C Tag