Patent ID: 9292782
Filing Date: 2016-03-22
CPC Classification: G06K

Claim Text:
1. A transceiver, comprising: a matching circuit coupled to a near field communication (NFC) antenna and including first and second adjustable capacitors; an envelope detector responsive at least in part to mutual inductance variations in the NFC antenna from an NFC handshaking device, the matching circuit coupled between the envelope detector and the NFC antenna and the matching circuit including a first series capacitor and the first adjustable capacitor in shunt together forming a first voltage divider configured to generate a reduced input signal to a first input of the envelope detector and a second series capacitor and the second adjustable capacitor in shunt together forming a second voltage divider configured to generate a reduced input signal to a second input of the envelope detector; and a sensor configured to sense a voltage at an output of the envelope detector and adjust a capacitance of the first and second adjustable capacitors based on a peak voltage at the output of the envelope detector determined by sweeping a spectrum of capacitance values of the first and second adjustable capacitors.