Citation
Abstract
Analysis and practical application of third-order phase-lock design have been sporadic, compared with the second-order, in both the servomechanism and telecommunication fields. The attractiveness of minimal tracking errors resulting from near “perfect” third-order filtering (three true integrators) has been largely offset by undesirable acquisition properties and to some extent by a dearth of analysis of this configuration. A useful approach, both in viewpoint and in design, is to consider the prevalent “imperfect” second-order and third-order configurations for what they are—namely, loops with one integrator augmented by one or two lag time constants, so proportioned with respect to loop gain as to approximate the closed-loop response of true second- and third-order configurations, while manifesting a controlled (but not infinite) improvement in tracking performance over the first-order loop. This article seeks to apply this approach to the existing work in third-order analysis, and to emphasize the principal effects, both positive and negative, of the relative proportioning of loop gain and time constants, with a view toward practical exploitation of the best features of these loop configurations.
Details
- Volume
- VIII
- Published
- April 15, 1972
- Pages
- 99–110
- File Size
- 1019.8 KB