Study on carrier cancellation in UHF RFID test system

First, the UHF RFID tag test system is introduced in the paper and the carrier leakage issue in the test system had been illustrated. Then the paper analyzed the effect of carrier leakage impacting tag test. And the solution had been given that designing the carrier cancellation circuit before the receiver in order to suppress the leakage RF power. The circuit should adjust the amplitude of transmitting carrier to equal the receiving carrier and adjust the phase reverse to receiving carrier. The adjustment of circuit should complete automatically and quickly enough. At the end the test had been implemented and the data result had verified the actual effect of carrier cancellation.