Advanced Frequency Synthesis by Phase Lock

PREFACE

This book is a continuation of Frequency Synthesis by Phase Lock, 2nd edition (FS2), for the purpose of expanding coverage of techniques that have become more important since its publication and to introduce new techniques. The area of increased importance is primarily sigma–delta (ΣΔ) synthesis, while all-digital synthesizers represent the emerging technology, and diophantine synthesis shares some of both characteristics. We will depend on FS2 to define the assumed technical background, without requiring that it be acquired there. We will also make extensive use of Simulink^® models, without requiring their use by the reader.

Frequency synthesizers that employ ΣΔ modulators offer the potential to provide wide bandwidth simultaneously with fine resolution (step size), plus other advantages. When Frequency Synthesis by Phase Lock, 2nd edition, was published in 2000, they were rare and considered exotic. Since then, they have become widely used in high-production consumer electronics, where they are valued for their compatibility with IC technology. The theory of their operation was discussed in FS2 but, as would be expected, much valuable information has become available since that time. This, and their new prominence, now justifies greater attention.

We will consider the fractional-N synthesizer, of which ΣΔ is a special case, as a whole, moving from simple fractional-N, through analog compensation, into ΣΔ modulation. We will do so in a measured fashion, as if by experimental ...