Physical property sensor with active electronic circuit and wireless power and data transmission

摘要

Wireless sensors configured to sense, record and transmit data are provided herein. In one aspect, the wireless sensor has a power harvesting unit; a transducing A-to-D converter unit, a microcontroller unit, and a transmitting coil. The power harvesting unit is configured to receive an external energizing magnetic field generated by an external interrogator and store the energy generated thereby. The transducing A-to-D converter unit has a passive electrical transducer configured to respond to variations in a physical property and a converter configured to measure a characteristic value of the passive electrical transducer and provide a digital signal that is indicative of the measured characteristic value. The microcontroller unit is electrically coupled to the power harvesting unit and the transducing A-to-D converter unit and is configured to receive the digital signal from the transducing A-to-D converter unit. The transmitting coil is configured to receive the digital signal and to transmit the digital signal to the external interrogator. Upon receiving a start signal, the transducing A-to-D converter unit charges a current through the passive electrical transducer until a reference voltage is reached and, upon reaching the reference voltage, the microcontroller unit receives the digital signal.