James Chu
Mouqun Dong received his Ph.D. degree in physics from Syracuse University and has been an RF application engineer at California Eastern Laboratories for nearly 18 years. He has also worked on wireless product development at Qualcomm (formerly Atheros Communications). Before joining industry, he was an academic scientist conducting research at Stanford University’s Hansen Lab on a project concerning microwave frequency standards.
This book is about the theory of RF circuits and systems and the practice of designing them. It is primarily intended for practicing RF engineers who are involved in printed circuit board (PCB)-based circuit design and system integration, with a focus on two particular groups of readers:
All the practical design techniques covered in this book are for PCB-based circuits. The subject matter in this book was selected and presented with a primary motive: to be relevant to practitioners. This book uses numerous practical examples to clarify the concepts and facilitate discussion. Many of the circuit examples throughout the book and the comments on how analysis results can be used in everyday engineering practice are from the author’s own experience. In addition, the background information was chosen by the author to be useful to fellow engineers.
The book can also be used as a supplementary text for a college-level introductory course in RF and microwave engineering. Some treatments in this book, provided from a practical perspective, may help students better understand the subject matter in the context of actual applications.
In Chapter 1, “Essentials of Radio Frequency (RF) Circuits and S-Parameters,†the author introduces basic RF/microwave circuit quantities and rules that are the foundation of the theory of RF circuits. It skips the derivations and, instead, presents a few basic concepts and rules as the starting point for the discussion. The discussion includes transmission lines, characteristic impedance, and scattering parameters (S-parameters).
Chapter 2, “Circuit Analysis Using S-Parameters,†discusses how S-parameters can be used in RF circuit design; the materials presented in this chapter apply to any device characterized by S-parameters. However, the discussions of transducer and power gain and stability circles are the most relevant to amplifier design. The chapter dives deep into stability circles, reflection coefficients, and S-parameters. The invariant property of the mismatch factor is an important concept in the design of lossless networks. It demonstrates that a linear RF amplifier design is possible through the determination of source reflection and load reflection through an S-parameter analysis of the device based on the circuit requirements of stability, gain, and return losses and the design of input and output matching networks.
Chapter 3, “Matching Networks and the Smith Chart,†covers the design of matching networks, focusing on the Smith chart, which is the principal approach to the design of RF matching networks.
Chapter 4, “Noise and Its Characterization in RF Systems,†focuses exclusively on intrinsic noise except for a brief discussion of background thermal noise in the context of satellite communication systems. It also explains the characteristics of several common types of noise, with an emphasis on thermal noise. Then, it introduces the equivalent noise circuit. Finally, it discusses in great depth the noise figure, an especially important concept in low-noise RF circuit design.
Chapter 5, “RF Amplifier Designs in Practice,†discusses various practical design issues with an emphasis on PCB-based RF amplifier circuits. Materials in this chapter are mainly, but not completely, limited to linear circuits, and the chapter focuses on linear parameters. The frequency characteristics of an amplifier are usually the first specification to be considered. Most wireless protocols operate in a relatively narrow frequency band, simply because of spectrum restrictions by regulatory agencies.
Chapter 6, “RF Power Amplifiers,†covers a few very basic concepts in power amplifier design, from an application perspective. This chapter also examines the conditions for power optimization, two popular nonlinearity specifications of the 1-dB compression point, and the third-order intercept point. For the design of ultrahigh power (20–30-W) amplifiers, the author covers many critical factors to consider, including component selection, dc bias circuit design, thermal properties, electrical characteristics at extreme conditions, and impedances for matching.
Chapter 7, “Efficiency of RF Power Amplifiers,†discusses the techniques for waveform manipulation of high-efficiency RF amplifiers, which cover classes A, AB, B, C, E, and F, and Doherty power amplifiers. This discussion, which focuses on the relevance to the actual circuit performance, shows that the desired waveforms for efficiency enhancement are usually generated when the RF transistors are driven near or into compression.
Chapter 8, “RF Designs and Wireless Communications Systems,†aims to present these concepts without the burden of analytical rigor. The chapter’s focus is on explaining why the issues under consideration are important from the standpoint of system performance. It covers basic wireless communication transmitters and receivers and the related components and systems.
Chapter 9, “Passive Components in RF Circuits,†covers passive components used in RF applications, a category that encompasses a wide variety, such as capacitors, inductors, resistors, directional couplers, circulators, power dividers, and combiners. The discussion in this chapter focuses on those components that are most commonly used in PCB-based circuits as well as in RF measurement setups. The author further narrows the scope to the component characteristics that have a direct impact on RF performance, such as tolerance, thermal and mechanical properties, and RF power wave manipulations.
Chapter 10, “RF Measurements,†is devoted to several measurement techniques that are commonly used for the characterization of RF circuits and systems. It focuses mainly on the practical aspects of these techniques in applications, with special attention to the operation of the pertinent measurement instrument. It includes S-parameters, through-reflect-line standard calibration, and a few more techniques. It also explains the phase noise, resolution bandwidth, and frequency stability measurements.
Chapter 11, “RF Switches,†discusses the applications of discrete RF switches in circuit and system design. First, the author mentions that, in general, there are two major groups of RF switches: 1) electromechanical switches, including microelectromechanical system (MEMS) devices, and 2) solid-state (or semiconductor) switches. The chapter explains the operating principles behind some of the RF switch characteristics commonly considered in applications.
The 11 chapters in this book cover most of RF engineering technology from A to Z. It is a perfect book for RF engineers and college students. It gives a broad introduction from basic to advanced, with not too much theory but very rich in practical working knowledge. This book also fits the needs of every RF design engineer, with so many good examples they can use to solve everyday RF engineering problems. Having this book on your bookshelf will make your RF design job a lot easier.
Digital Object Identifier 10.1109/MMM.2023.3265483
