UHF RFID tags backscattered power measurement in reverberation chamber

Presented is a methodology for measuring the power backscattered by ultra-high frequency radio frequency identification (UHF RFID) tags by using a modes stirrer reverberation chamber. The actual measurement methodology is described and its advantage and disadvantage against the conventional setup using anechoic chambers are outlined. Then, some results of power measurements performed with the three Gen2 class 1 tags are presented. The experimented tags´ sensitivity and radiation efficiency as a function of incident power are finally derived. The results are very encouraging and demonstrate the feasibility of such a characterisation in modes stirred reverberation chambers. All the measurements were carried out at a single frequency of about 866 MHz.