Patent ID: 8260200

Claim:
A non-contact wireless communication apparatus which receives a power supply from an external device by inductive coupling in a non-contact manner, to transmit/receive a signal with the external device, the non-contact wireless communication apparatus comprising: a non-contact wireless communication antenna; a resonance capacitor, connected in parallel with the non-contact wireless communication antenna, for obtaining a predetermined resonance frequency with the non-contact wireless communication antenna; resonance frequency adjustment means for changing a resonance capacitance of the resonance capacitor to adjust the resonance frequency; capacitance change amount control means for controlling an amount of change in resonance capacitance of the resonance capacitor in the resonance frequency adjustment means; resonance frequency shift means for shifting the resonance frequency of the non-contact wireless communication antenna; and on/off control means for performing on/off control of the resonance frequency shift means in accordance with the amount of change in the resonance capacitance of the resonance capacitor by the capacitance change amount control means, wherein the resonance capacitor is connected in parallel with the non-contact wireless communication antenna and is connected in series to one end of each of a first capacitor and a second capacitor of an adjustment circuit, wherein the other end of the first capacitor is connected to a source of a first field effect transistor, and a drain of the first field effect transistor being grounded, and the other end of the second capacitor being connected to a source of a second field effect transistor, a drain of the second field effect transistor being grounded.