What is the role of a physical book in an electronic world?
I recently got a copy of the newest edition of Spectrum and Network Measurements by Bob Witte. This is the second edition, and it was a good time for an update. It’s been more than a dozen years since the previous one, and I think an earlier, similar work by Bob first appeared in the early 1990s. Bob has a deep background in measurement technology and was, among other things, a project manager on the first swept analyzer with an all-digital IF section. That was back in the early 1980s!
One of the reasons for the update is apparent from the snapshot I took of the cover.
The cover highlights a relatively recent display type, variously referred to as density, cumulative history, digital phosphor, persistence, etc. These displays are a characteristic of real-time spectrum analyzers, and both the analyzers and displays were not in mainstream RF use when the previous edition of the book appeared.
An update to a useful book is great, of course, but why paper? What about a website or a wiki or an eBook of some kind? Digital media types can be easily updated to match the rate of change of new signals, analyzers and displays.
In looking through Bob’s book I’ve been trying to understand and to put into words how useful it feels, in just the form it’s in. It’s different from an app note online, or article, or Wikipedia entry. Not universally better or worse, but different.
Perhaps it’s because while some things have changed in spectrum and network measurements, so many things are timeless and universal. The book is particularly good at providing a full view of the measurement techniques and challenges that have been a part of RF engineering for decades. It’s a reminder that making valid, reliable, repeatable measurements is mostly a matter of understanding the essentials and getting them right every time.
Resources online are an excellent way to focus on a specific signal or measurement, especially new ones. Sometimes that’s just what you need if you’re confident you have the rest of your measurements well in hand.
I guess that’s the rub, and why a comprehensive book like this is both enlightening and reassuring. RF engineering is a challenging discipline and there are many ways, large and small, to get it wrong. This book collects the essentials in one place, with the techniques, equations, explanations and examples that you’ll need to do the whole measurement job.
Of course there are other good books with a role to play in RF measurements. While Bob’s book is comprehensive in terms of spectrum and network measurements, one with a complementary focus on wireless measurements is RF Measurements for Cellular Phones and Wireless Data Systems by Rex Frobenius and Allen Scott. And when you need to focus even tighter on a specific wireless scheme you may need something like LTE and the Evolution to 4G Wireless: Design and Measurement Challenges*, edited by Moray Rumney.
All of these are non-eBooks, with broad coverage including many examples, block diagrams and equations. Together with the resources you’ll find using a good search engine, you’ll have what you need to make better measurements of everything you find in the RF spectrum.
*Full disclosure: I had a small role in writing the signal analysis section of the first edition of the LTE book. But it turned out well nonetheless!