Increasing dynamic range of RFID tag self-tuning

摘要

An RFID tag tuning circuit is capable of tuning the impedance matching between an RFID integrated circuit (IC) and an antenna on an RFID tag to increase the amount of power that the IC can extract from an incident RF wave. The tuning circuit tunes the impedance matching by adjusting a variable impedance coupling the antenna and the IC. Prior to tuning, the variable impedance is set using a voltage output from a tuning switch stage of an IC rectifier.