the new Chapter 9.
Chapter 7 has additions in the area of multichannel mixer test with a new method for measuring phase difference between multichannel mixers, as well as a new method for absolute phase measurements of a mixer. Also added is a new method for swept higher‐order products measurements. An entirely new section on measuring I/Q mixers has been added. As with amplifiers in Chapter 6, the topic of noise figure measurements of mixers has been consolidated in the new Chapter 9.
Chapter 8 is almost entirely new and adds the new topic of measuring components with modulated signals to the realm of modern VNA testing. First, I give detailed discussion of how VNAs can perform spectrum analysis and details of modulated signal characteristics particularly related to when they are generated as a waveform played back on an arbitrary waveform generator. Then new methods for extremely accurate power measurements on modulated signals are introduced. Methods for measuring distortion in the form of adjacent channel power is covered, along with noise power ratio. A new method for using a VNA to directly measure error vector magnitude (EVM) on power amplifiers is introduced. Finally, new methods for pulsed spectrum measurements are discussed. This chapter contains a lot of detail on spectrum analysis that was previously not well known and fully explains the differences one sees in the appearance of a spectrum when applying different measurement and detection methods.
Chapter 9 collects the topics of noise figure measurements for both amplifiers and frequency converters into a single chapter. New material on noise parameter measurements is included, as well as a new section on measuring the noise figure of an active antenna. Further, there is a detailed discussion on a new method for noise‐figure verification.
Chapter 10 now contains all the information on differential measurements. New material on measuring the differential harmonics of differential amplifiers has been added, as well as making IMD measurements without using baluns. A new technique is shown for determining the phase skew of a differential amplifier.
Chapter 11 contains the material on advanced techniques for fixturing and creating calibration kits, with various other topics (previously Chapter 9). This contains new material on the one‐port (open only) automatic fixture removal (AFR) method.
Several of these new capabilities are introduced that dramatically change the way components may be tested. These include the integration of full spectrum analysis capabilities in a VNA, and the ability to synchronously control the frequency, power, and phase of multiple sources while measuring at multiple different frequencies. These capabilities are generally implemented in the form a purpose‐built application function. While details of how these functions operate can vary between instrument manufacturers (and frankly, between different versions of firmware from a single manufacturer), the key concepts are explained to allow the reader to fully understand the benefits of these new methods.
I would like to thank my colleagues from Keysight Technologies for their assistance in reviewing this material and for their help in developing the new material. As always, any mistakes are mine alone.
Joel P. Dunsmore
Sebastopol, CA
July 2019
Preface to the First Edition
This book is a bit of mixture between basic and advanced, and between theoretical and practical. Unfortunately, the dividing lines are not particularly clear and depend considerably upon the training and experience of the reader. While primarily a text about measurements techniques, there is considerable information about device attributes that will be useful to both a designer and a test engineer, as one purpose of device‐test is to ascertain attributes of devices that do not follow the simplified models commonly associated with these devices. In practice, it is the unexpected responses that consume a majority of the time spent in test and troubleshooting designs, particularly related to active devices such as amplifiers and mixers.
The principle instrument for testing microwave components is the vector network analyzer (VNA), and recent advances have increased the test capabilities of this instrument to cover far more than simple gain and match measurements. As a designer of VNAs for more than 30 years, I have been involved in consulting on the widest range of microwave test needs from cell phone components to satellite multiplexers. The genesis and goal of this book are to provide to the reader a distillation of that experience to improve the quality and efficiency of the R&D and production test engineer. The focus is on modern test methods; the best practices have changed with changing instrument capability and occasionally the difference between legacy methods and new techniques are sufficiently great as to be particularly highlighted.
Chapter 1 is intended as an introduction to microwave theory and microwave components. The first half introduces characterization concepts common to RF and microwave work. Some important mathematical results are presented that are useful in understanding the results of subsequent chapters. The second half of Chapter 1 introduces some common microwave connectors, transmission lines, and components, as well as some discussion of the basic microwave test instrumentation. This chapter is especially useful to engineers new to RF and microwave testing.
Chapter 2 provides a detailed look into the composition of common VNA designs along with their limitations. While this level of detail is not normally needed by the casual user, test engineers trying to understand measurement results at a very precise level will find it useful to understand overall results are affected by VNA test configuration. While the modern VNA can make a wide range of measurements, including distortion, power, and noise figure measurements, still the principal use is in measuring S‐parameters. The second half of Chapter 2 illustrates many useful parameters derived from basic S‐parameters.
Perhaps the most arcane aspect of using VNAs for test is the calibration and error correction process. Chapter 3 is a comprehensive discussion of the error models for VNAs, calibration methods, uncertainty analysis, and evaluation of calibration residuals. This chapter also introduces the idea of source and receiver power calibrations, about which, excluding this book, very little formal information is currently available. The chapter concludes with many practical aspects of VNAs that affect the quality of calibrated measurements.
Chapter 4 may be the most mathematically rigorous, covering the very useful topic of time‐domain transforms used in VNAs. The topic of gating, its effects, and compensation methods is examined in particular. These first four chapters comprise the introductory material to microwave component measurements.
The remaining chapters are focused on describing particular cases for microwave component measurements. Chapter 5 is devoted to passive microwave components such as cables and connectors, transmission lines, filters, isolators, and couplers. Best practices and methods for dealing with common problems are discussed for each component.
