Phase-Locked Loop Bandwidth and Signal-to-Noise-Ratio Requirements for Deep-Space Communications

Properly designed phase-locked loops play a key role in deep-space communication links. The interrelationships among the loop band-width, acquisition time, and the loop signal-to-noise ratio are established for a given probability of acquisition. The Doppler rate tracking capability of the second-order loop is considered. The probability of time to lose lock is derived by the Fokker-Planck techniques. The results of the study are used to determine the loop bandwidth and the signal-to-noise ratio requirements of Venus and Jupiter probes' communication links.