| 摘要 |
<p>An input signal (IN) is filtered (605) to remove aliases and a switched capacitor network (610) undersamples this signal to provide a downconverted, near-baseband signal. An amplifier (615) adjusts the amplitude of this signal to match a digitizer (620). The digitized output is converted into first phase and second phase signals which are then filtered (640) and decimated (645) to further reduce the sampling rate. The downconverted first an second phase signals, rather than higher frequency signals, control the gain function (AGC) for the amplifier (615). The switched capacitor network (610) provides for both tuning and downconversion of the desired signal to a lower frequency for further processing, thus reducing the frequency and power requirements of an associated amplifier and analog-to-digital converter (digitizer).</p> |
