A wideband all-digital phase-locked loop
Abstract
The phase-locked loop system has already been widely used for timing-wave extraction, AM and FM demodulation, and frequency synthesizing in communication systems, with the shortcoming that the locking range decreases with increasing jitter suppression. The present paper proposes a wideband all-digital phase-locked loop which controls the output phase by binary quantized signals for a large jitter suppression effect. The effectiveness of this system is investigated both experimentally and theoretically. The output phase distribution is derived for the case where the system has a fixed self-running frequency. The calculated output jitter and locking state are in good agreement with the measured results. The system makes it possible to spread the locking range under a small output phase jitter. In order to realize a large jitter suppression effect and improve transient characteristics in a wide phase-locking range, it is necessary to detect the frequency difference and phase difference separately, using two separate detectors.
- Publication:
-
Electronics Communications of Japan
- Pub Date:
- March 1975
- Bibcode:
- 1975JElCo..58...27Y
- Keywords:
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- Digital Systems;
- Noise Reduction;
- Phase Locked Systems;
- Signal Detection;
- Transmission Efficiency;
- Wideband Communication;
- Amplitude Modulation;
- Data Transmission;
- Frequency Modulation;
- Phase Control;
- Signal Stabilization;
- Steady State;
- Transient Response;
- Communications and Radar