Apparatus and methods for real-time resonance adaptation for power receiver

A wirelessly powered sensor chip, comprising:

• an inductive coil that receives wireless power from an external transmitter;
• a capacitor bank that specifies different settings for different external environments surrounding the sensor chip;
• a power-receiving frontend RF-DC rectifier with a periodically enabled closed feedback loop that adapts settings of the capacitor bank in real-time to adapt to the surrounding environment;
• and
• a transmitter that transmits information related to the capacitor settings and voltage readings to an external controller.

A sensor system comprising:

• an implantable sensor chip configured for placement relative to a surrounding environment, comprising:
• an inductive coil configured to receives power from an external transmitter;
• a capacitor bank having an input coupled to the inductive coil, the capacitor bank comprising a plurality of capacitors configured to be selectively included in one or more of a plurality of capacitor-bank settings;
• an amplitude detector having an input coupled to the input of the capacitor bank and an output, the amplitude detector configured to provide measurements of the input of the capacitor bank;
• a resonance compensator having outputs coupled to the capacitor bank and an input coupled to the output of the amplitude detector, the resonance compensator configured to:
• sample the measurements of the input of the capacitor bank through the amplitude detector, and select an optimal capacitor-bank setting based on the measurements of the input of the capacitor bank in real-time to adapt to the surrounding environment;
• a transmitter configured to transmit information related to the capacitor-bank settings and voltage readings;
• and
• an external controller configured to receive and process the transmitted information related to the capacitor-bank settings and voltage readings to determine as aspect of the surrounding environment.