Low-Power Wireless Uplink Utilizing Harmonic With an Integrated Rectifier–Transmitter

A novel integrated rectifier–transmitter (IRT) that targets to reduce the power consumption of the uplink communication of a wireless sensor is presented in this letter. The proposed IRT fully utilizes the second harmonic generated by the rectifier as the uplink carrier and modulates this carrier in amplitude through a reconfigurable bandstop filter (BSF) that is dynamically biased by the uplink baseband signal. As a proof of concept, an IRT prototype operating at 2.4 GHz has been implemented and characterized. We report the power conversion efficiency (PCE) to prove that the modulation does not affect the rectification of IRT. An uplink data rate of 100 kb/s has been demonstrated when the IRT is fed with −20-dBm RF power.