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These notes from a seminar given by HP in the mid-80's serve as a useful reference for some of the fundamental relationships governing phase noise. Needless to say, some of the most recent techniques in phase noise measurements are not represented, but the mechanisms that generate phase noise are described in useful detail.
This is a detailed article comparing phase noise measurement techniques and their advantages and disadvantages. You will need to be a member of the Microwave Theory and Techniques society of the IEEE to view the article for free. A purchase option may be available if you are not a member.
Update November 2021: login no longer required to use this app! Visit the reflectometer page (HTML5/JavaScript version)
The old Java version is still available.
A busy, often humorous site filled with information for RF and wireless engineers and technicians.
RF Cafe is a unique portal of RF, microwave, wireless, and other engineering resources. Vast collection of equations, references and conversions for electrical, mechanical, physical, and mathematical fields. Links for vendors, app notes, test notes, ham radio, magazines, books, active forums, patent and communications standards, technical crossword puzzles, quizzes, and much more.
Free software for Windows that allows you to perform several different system calculations.
From the website:
Reference book for using probes and test fixtures in RF measurements.
This is undoubtedly the most accessible book on digital signal processing available to the beginner. Using intuitive explanations and well-chosen examples, this book gives you the tools to develop a fundamental understanding of DSP theory.