This book is about the theory and practice of spectrum and network measurements in electronic systems. It is intended for readers who have a background in electrical engineering and use spectrum analyzers and network analyzers to characterize electronic signals or systems.
This is the book that I wish someone had handed me when I started my career as an electrical engineer. This work was formed from thousands of interactions with my fellow engineers at HP, Agilent Technologies, and now Keysight Technologies about this or that measurement challenge. My target reader is the recent electrical engineering graduate or an engineer recently tossed into the challenge of performing spectrum or network measurements. For inspiration, I often think about the electrical engineering students I have taught and then write with the goal of helping them apply that big pile of electrical theory in their heads.
Since the first edition was written, the body of knowledge in this area has grown dramatically. Rather than triple the size of the book, I chose to keep it focused on the core measurement principles and list key references for further study. This second edition does reflect the dramatic impact of digital technology, driving significant change in the systems being measured, and the technology used inside the measuring instruments. Every chapter of the book has been impacted by this important shift.
The concept of wireless communication has been around for decades, evolving from spark gap transmitters to handheld digital mobile phones. Spark gap transmissions relied on Morse code (the original digital format), occupied wide spectrum bandwidth, and were relatively inefficient. Over time, communication systems adopted AM and FM analog modulation techniques to implement amplitude modulation and frequency modulation broadcast radio, two-way radio, and early cellular telephones. More recently, digital formats have emerged as the most efficient and versatile modulation schemes. It has been fascinating to witness the explosion in wireless communications devices, and it is not over yet.
A merging of wireless and digital technology is producing an unprecedented level of electronic connectivity in our society. The increasing usage of wireless devices has caused a corresponding high demand for engineers and technicians who understand radio frequency and microwave circuits and systems. Despite these recent changes in technology, the fundamentals of signals propagating through circuits and through the air have not changed. The basic theory of signals and systems and the measurements that accompany it still apply. Concepts such as Fourier analysis, transmission lines, intermodulation distortion, signalto- noise ratio, and scattering parameters (S-parameters) represent a critical foundation for this new era of wireless development. The purpose of this book is to enable the reader to understand that basic theory, to relate it to measured results, and to apply it in creating new RF and microwave designs.
Although some of the internal functions of spectrum analyzers and network analyzers are discussed, the real emphasis of the book is on the theory and practice of frequency domain measurements. Enough theory is provided so that the reader can understand how a particular measurement is made, what the possible sources of error are, and the significance of the results. Many numerical examples are given to aid the reader in understanding the material and to help relate theory and practice.