Phase-Lock Basics

Rating:
Summary: Good treatment of core subject, but difficult for beginner
Review: I am new to phase-lock loop design. Like most recent EE grads, I had one class in linear control systems, and some basic DSP classes, but thankfully that's enough to get started on PLL design.

I haven't finished Egan's book, but so far I think I can make some generalizations about his writing style. He redefines some 'common concepts' (like frequency) as "frequency + phase." You have to read carefully, otherwise you might miss his redefinition, and that will cause you confusion for the rest of the book. I don't like how he simply writes down formulas without any kind of symbol explanation. He explains the formulas well, but a simple 'w_c = carrier frequency component, f_m = modulation frequency component' alongside the formulas would really help. Symbols are re-used quite often, so one variable may change meaning from one page to the next...This means you can't just skip around the book without carefully reading the accompanying text passages.

These minor annoyances aside, the content is excellent. He spends a little time covering "basic material", for example bode-plots, root-locus, nyquist plots, and shows how these basic tools can aide a qualitative understanding of PLL steady-state stability. (Everything is cast as a second-order system, which is easy to hand-decompose.) This is important, because once you read about the non-linear regions of PLL behavior, it's easy to get lost in the math.

Rating:
Summary: Excellent Book
Review: This is my favorite book on phase locked loops in my entire library. It is an excellent book for actually learning phase locked loops from the ground up.

I have been involved in PLL design for four years. Reading through this book last year provoked a series of, "Aha!" moments and "That's an excellent way to phrase that," comments.

Egan has the knack of taking concepts which should be familiar to anyone with a degree in electrical engineering, and extending them easily to the very specific study of phase locked loop systems. His writing is clear and straight forward, and his analogies and examples are well chosen.

And happily, he does NOT make use of the age-old (and incomprehensibly useless to most of us) mechanical damping or servo systems.

This should be the first book on PLLs you read. Then you can move on to Rohde, et al.