| 摘要 |
A near field RF communicator has an antenna circuit (120) to receive a modulated radio frequency signal by inductive coupling and demodulation circuitry (130 or 131) to extract the modulation from a received modulated radio frequency signal inductively coupled to the antenna circuit. The demodulation circuitry has a virtual earth input comprising a current mirror. The demodulation circuitry may be formed by an amplifier (115 or 116) and a demodulator (114) coupled to an output of the amplifier. The amplifier may be a single input amplifier (116) coupled to an output of the antenna circuit or may be a differential amplifier (115) having first and second inputs to receive the modulated radio frequency signal from first and second outputs of the antenna circuit, with each amplifier input providing a virtual earth input.
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