| 摘要 |
A method of demodulating an amplitude modulated (AM) radio signal is disclosed. The method comprises directing the modulated signal 302 to both a phase detector 308 and an edge detector 314, and using the respective output signals 310, 318, 320 of the phase detector 308 and edge detector 314 to determine an end of a modulation symbol 340 in the signal 302. The disclosed circuit is particularly suitable for demodulating Amplitude Shift Keyed signals (ASK), e.g. for carrying data to a near-field communicator (NFC) device. The circuit demodulates data with reduced timing uncertainty (348, fig.4) when compared to the uncertainty (346, fig.4) associated with the lock detection signal as used in a conventional phase locked loop (PLL) demodulation arrangement. |
