Preface

It is the responsibility of every author to answer the proverbial question "Why is there another text on such an established subject?" There is a plentitude of quality texts that thoroughly cover electromagnetics and transmission lines, usually in two semesters. We deviate from the norm in this text with an explicit mission and goal:

Mission: What every electrical engineer, not just the electromagnetics specialist, should know about electromagnetic fields and transmission lines.

Goal: A textbook that enables completion of static electric and magnetic fields, dynamic electromagnetic fields, transmission lines, antennas, and signal integrity within a single course.

With this mission and goal in mind, we have designed a text that conveys rigor to the depth consistent with the mission and goal of the text, yet focuses on the essential concepts of electromagnetics and transmission lines and excludes those that are generally considered specialized. Admittedly this approach involved experiential judgments and strategic trade-offs. We mitigated some of the agony of topic exclusion by placing select topics into chapter appendices. For example, the differential forms of electromagnetics laws are not utilized in the main body of the text, but Maxwell's equations in differential form are introduced in a chapter appendix.

It is intended that the reader progresses through the sections in the main body of the text without the chapter appendices. The page count of the entire text was intentionally constrained for use in a single semester course. Overall, this focused approach on electromagnetic fundamentals provides the essentials for all electrical engineers yet also provides a solid electromagnetics foundation for students who wish to continue studies in elective or graduate-level electromagnetics courses.

Chapter appendices can be included or excluded without compromising the pedagogic and topical flow within the body of the work. If an appendix depends on a previous appendix, this association is declared initially within the appendix. The availability of chapter appendices adds a degree of content flexibility for those programs that have covered content from the earlier chapters in other courses (such as the first chapter), have multiple courses, have more credit hours, and so forth, to accommodate additional instructional content per specific course requirements.

A primary feature of the text is the inclusion of the underlying concepts of the vector network analyzer (VNA) as well as a brief but focused introduction to the instrument. Modern VNAs are cost-effective and utilized significantly in a wide range of electronic industries. We hope that this text serves as a primer for effective understanding of the VNA.

End-of-text appendices are included upon the recommendation of multiple reviewers. A valuable suggestion in this regard was to include a symbols listing (Appendices A and B). Four pages of symbols resulted! Students who are new to the subject matter often mention the difficulty of learning so many new symbols. This exercise confirmed the multitude of symbols that are used in electromagnetics (so instructors, be patient when you hear this comment). Tables with approximate values of physical constants and material properties (Appendices C and D) are given to communicate a "feel for the numbers" and for consistent usage in homework problems, not to be a reference of precise numbers which are readily available online. The equation summaries at the end of each chapter are collected in Appendix E.

The student background assumptions are multivariable calculus, DC and AC electric circuits, electromagnetic physics, and elementary differential equations. Multivariable integration is used extensively in several chapters. Cartesian vectors, the solution of two-dimensional point charge - static electric field problems using Coulomb's law, and basic concepts of static magnetic fields are normally a subset of electromagnetic physics courses. Additional topics in the physics of electromagnetics are helpful but not necessary. Elementary differential equations, namely a second-order linear differential equation with constant coefficients, are required for the modeling and solution of the phasor transmission line wave equation.

Organization

The latter part of this text covers applications with which any electrical engineer should be familiar: transmission lines, antennas, and basic concepts behind signal integrity. The pedagogy in the earlier chapters builds the essential concepts of electromagnetics and transmission lines that are prerequisite to these applications. The chapter descriptions follow.

• Chapter 1: Initially, vector algebra and coordinate systems are developed and examined carefully. The authors recommend that this material be mastered - do not assume it is automatically known. We have found in decades of teaching electromagnetic fields courses that students who have mastered vector algebra and coordinate systems perform and retain concepts significantly better than their counterparts who have not done so. The time spent in Chapter 1 is more than made up for in subsequent chapters because students learn subsequent material with a stronger background in "the vector tools," which results in more efficient and effective learning.
• Chapter 2: Coulomb's law and the Biot-Savart law, the superposition laws, are examined. We have grouped these two laws to reinforce the commonality of the superposition approach (we call this general approach "conceptual grouping"). The effective integration of a unit vector via implementation of symmetry is utilized to simplify resultant field expressions and, more importantly, to develop intuition into field behavior from canonical source geometries.
• Chapter 3: Gauss's law and solenoidal magnetic flux are similarly grouped to leverage the commonality of the flux viewpoint of fields. The visualization of an entire field pattern from canonical source distributions is the next natural step from the superposition laws of the previous chapter.
• Chapter 4: Electric potential, which we use interchangeably with the term "voltage" for static electric fields, and Ampere's circuital law are grouped to reinforce the commonality of the path law approach. Several fundamental electrical engineering applications are examined from the electromagnetic fields viewpoint, such as electric circuit laws, capacitance, self and mutual inductances, and basic magnetic circuit principles (the latter as a chapter appendix). They illustrate and reinforce the path law thinking as well as previously covered electromagnetic field concepts. Dielectric and magnetic material concepts are covered briefly. This static fields background sets the stage for time-changing electromagnetic fields.
• Chapter 5: Faraday's law, displacement current, and the integral form of Maxwell's equations are approached from a conceptual viewpoint to relate the mathematical expressions to physical understanding. Several fundamental electrical engineering applications are again utilized to reinforce the electromagnetic fields - circuit relationships. The differential forms of Maxwell's equations, including explanations of the del operator, divergence, and curl, are covered in a chapter appendix to provide exposure to the forms often encountered in the literature.
• Chapter 6: The concept of DC transient and AC steady-state waves and reflections on a transmission line (T-line) are examined initially. This approach leads into measures of reflection, Smith charts, and scattering parameters. The T-line model and electrical distance considerations are delayed until the next chapter. We have found that separating waves and reflections from electrical distance concepts improves the pedagogy because students are learning fewer concepts simultaneously. The VNA is introduced at the end of this chapter.
• Chapter 7: The concepts from Chapter 6 are expanded by modeling the T-line and solving for the AC steady-state voltage, current, and impedance expressions. AC standing waves and the Smith chart are consequently expounded. The visualization of T-line behavior via the Smith chart is emphasized. Many of the T-line relations that are utilized in practice result from this chapter. Some of the detailed mathematical developments that are not essential to the pedagogic flow are separated into the chapter appendices.
• Chapter 8: An intuitive explanation of electromagnetic radiation is used to introduce antennas. Uniform plane wave concepts are introduced with analogies to T-lines, and the Poynting vector is used to determine the power received from a uniform plane wave by an antenna. Basic antenna parameters such as antenna gain and beamwidths are examined. Finally, link loss is developed and applied via the Friis transmission equation to determine the power received in a link.
• Chapter 9: Signal integrity concepts are introduced. T-line effects are considered in the context of signal integrity. Crosstalk is related to Faraday's law and displacement current from Chapter 5. Electromagnetic interference (EMI), especially the measurements, is explained to a somewhat greater extent given that most students will not be familiar with this topic. Ground bounce is only mentioned. Electromagnetic safety/human exposure and...