| 摘要 |
A communications device includes a direct-conversion receiver for a radio frequency (RF) signal which is configured to receive the RF signal during defined time slots. A first input receives the RF signal and a first output outputs a baseband signal derived from the RF signal. A mixer module is configured to receive the RF signal and a local signal which is generated by a local oscillator. The mixer module generates an output signal which includes the baseband signal and an offset component. An amplifier module is connected between the first output and the mixer module, and includes a feedback loop which has in a backward path, a track-and-hold circuit. The track-and-hold circuit is configured to track the offset component during a first time slot and to hold a value of the offset component at an end of the first time slot until a subsequent second time slot begins. This held value is applied during the second time slot to the output signal in order to provide for fast compensation of the offset component.
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