| 摘要 |
In order to improve the phase skipping characteristic and the transient response characteristic when using a tracking filter to regenerate the carrier from a PSK signal, a pair of output points having different equivalent noise bandwidths are set by using a first filter having a broad equivalent noise bandwidth and a second filter having a narrow bandwidth. The phase difference between the output points is detected by a phase detector, the phase of the signal at the output point having the broader noise equivalent bandwidth being changed by a phase shifter if a phase difference is detected. The filters and associated circuitry can be connected in either parallel or serial configuration, and the frequency division necessary in the tracking filter can be accomplished in more than one stage to simplify the phase shifting requirement. Additionally either channel switching or polarity inversion of the demodulated baseband signal, or both, can be performed on the basis of such phase differences. |
