Citation
Abstract
Design parameters and resulting performance are presented for the sampled data analogies of continuous-time phase-locked loops of second and third order containing perfect integrators. Expressions for noise-equivalent bandwidth and steady-state errors are given. Then, stability and gain margin are investigated using z-plane root loci. Finally, an application is presented for Voyager subcarrier and carrier tracking under the dynamics of the encounters with Uranus and Neptune. For carrier tracking, loop bandwidths narrow enough for satisfactory loop SNR, can be achieved using third-order loops without rate aiding, whereas second-order loops would require aiding. For subcarrier tracking, third-order loops can be used when the sampling rate is limited to approximately once per second, as in the Baseband Assembly, whereas second-order loops sufficiently wide to track the dynamics have stability problems at that sampling rate.
Details
- Volume
- 42-79
- Published
- November 15, 1984
- Pages
- 81–95
- File Size
- 837.6 KB