Patent ID: 8781396

Claim:
A contactless receiver comprising: a receiving section having a resonant circuit to receive an input signal at a predetermined frequency, the resonant circuit including: a resonant capacitor comprising a variable capacitor comprising i) a ferroelectric layer and ii) electrodes arranged so as to apply an alternating current voltage of the input signal at the predetermined frequency to the ferroelectric layer to change a capacitance of the ferroelectric layer; and a resonance coil connected to the resonant capacitor; and a rectification section operable to convert the alternating current voltage output from the receiving section into a direct current voltage, wherein the ferroelectric layer of the variable capacitor has characteristics that the capacitance thereof increases according to the alternating current voltage of the input signal at the predetermined frequency applied thereto, in a first voltage range where the alternating current voltage of the input signal at the predetermined frequency applied thereto is smaller than a voltage corresponding to a maximum capacitance of the ferroelectric layer, and decreases according to the alternating current voltage of the input signal at the predetermined frequency applied thereto, in a second voltage range where the alternating current voltage of the input signal at the predetermined frequency applied thereto is larger than the voltage corresponding to the maximum capacitance of the ferroelectric layer.