| 摘要 |
The automatic frequency control method in a frequency and phase demodulator comprises steps (a) detecting the digital value of the DC component generated by the variation of the local oscillating frequency in the demodulating signal, (b) converting the digital value into the analog signal, and (c) generating the local oscillating frequency in accordance with the analog signal. A control circuit includes the first digital filter (107) for detecting the DC component of the demodulating signal, and the second digital filter (108) for attenuating the AC component of the demodulating signal included in DC component.
|
