A successful design and implementation of an RFID(Radio Frequency Identification)tag and reader.The RFID reader was implemented using a USRP board and GNU radio. TheRFID system designed here is considered a UHF(ultra high frequency) RFID. Thereader transmits and receives a 915MHz signal and demodulates the receive signalto read the data from the RFID tag. The data from the RFID tag is transmittedthrough back-scatter and modulated using BPSK. The RFID tag has a switch and amatching network to allow for the wave to be reflected at 0 degrees or 180 degrees byswitching from a short and an open.The RFID tag’s matching network was designed using ADS and is controlled withan on board MSP430 micro-controller. The matching network is L-match topologythat can be toggled to just a series inductor. It has the ability to change betweenthe two states using the MSP430 board and a second switch. The second switch iscontrolled at the same time as the main switch resulting in an open or short seen bythe antenna.Back-scatter is used in RFID because it uses very little power on the tag. Thehighest power consumption is by the MSP430 board. Even in the lowest power setting,it uses 60 micro-Watts. There are multiple ways to reduce the power consumption toreach the nano-Watt range but they were not implemented for this thesis. They areall discussed in the future work chapter.
