Method and apparatus for sensing environment using a wireless passive sensor

A method for execution by a radio frequency identification (RFID) tag, the method comprises:

• receiving, by an antenna of the RFID tag, a radio frequency (RF) signal from an RFID reader, wherein the RF signal has a carrier frequency of a plurality of carrier frequencies, wherein the plurality of carrier frequencies spans a broad frequency band;
• determining, by a tuning circuit of the RFID tag, a received power level of the RF signal at the carrier frequency;
• determining, by the tuning circuit, whether the received power level compares favorably to a power level threshold;
• and
• when the received power level compares unfavorably to the power level threshold, adjusting, by the tuning circuit, the input impedance of the RFID tag by adjusting a tank circuit of the RFID tag until the received power level compares favorably to the power level threshold, wherein the tank circuit is coupled to the antenna, and wherein the input impedance of the RFID tag is based on one or more of impedance of the antenna and impedance of the tank circuit.