US Patent 9789738 Pressure based wireless sensor and applications thereof

A wireless sensor includes an antenna, a tuning circuit, a pressure sensing circuit, a processing module, and a transmitter. Collectively, the pressure sensing circuit, the antenna, and the tuning circuit have one or more radio frequency (RF) characteristics and the pressure sensing circuit causes the RF characteristic(s) to vary with varying sensed pressures. The processing module detects a variance of the RF characteristic(s) from a desired value. In response to the detecting of the variance, the processing module adjusts the tuning circuit to substantially re-establish the desired value of the RF characteristic(s). The processing module generates a message regarding the adjusting of the tuning circuit, wherein a level of the adjusting is representative of a variance of pressure sensed by the pressure sensing circuit. The transmitter transmits the message.