Читать книгу Handbook of Microwave Component Measurements - Joel P. Dunsmore - Страница 12

It has been seven years since the first edition of this book, and while the fundamentals of RF and microwave component measurement (and thus the fundamental chapters) are largely unchanged, the advent of new methods and technologies has greatly increased the capabilities of the vector network analyzers, furthering the trend to fully integrated test solutions for complete component characterization.

Chapter 1 has been updated with better measurements of high‐frequency connectors (3.5, 2.4, 1.85, and 1 mm) showing their response and moding characteristics, as well as adding some discussion on new modulation measurements such as noise power ratio (NPR) and adjacent channel power ratio (ACPR).

Chapter 2 adds new material on multiport network analyzers with very large port counts and new broadband mm‐wave network analyzers.

Chapter 3 has been somewhat simplified with respect to details of power calibration (deleting some obsolete methods). Added were details on in‐situ calibration modules (CalPods), a new concept of calibrating multiple channels and measurements with a single calibration (i.e. cal‐all), and a new discussion of real‐time uncertainty capability.

Chapter 4's theoretical material is unchanged (the Fourier transform remains as it was), but a new section on simulated time‐domain reflectometer (TDR) measurements including eye diagrams has been added.

Chapter 5 is essentially unchanged, with just some minor updates.

Chapter 6 keeps the basics of amplifier test unchanged but adds several new topics including improved harmonic measurement methods, a method for testing dual input Doherty‐type amplifiers, an updated discussion of X‐parameters, and a new discussion of active or Hot S‐parameters. The topic of distortion measurements (2‐tone intermodulation distortion [IMD]) has moved to the new Chapter 8. The discussion of noise figure measurements has been moved to its own chapter, 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