About the authors
William H_ Hayt, Jr. (deceased ) received his B.S. and M.S. degrees al Purdue Uni-
versity and his Ph.D. from the University of Illinois. After spending four years in
industry. Professor Hayt joined the faculty of Purdue Universicy. where he served as
professor and head of the School of Electrical Engineering,and as professor emeritus
after retiring in 1986. Professor Hayt's professional society memberships included
Eta Kappa Nu. Tau Beta Pi. Sigma Xi, Sigma Delta Chi. Fellow of IEEE. ASEE. and
NAEB. While at Purdue. he received numerous teaching awards. including the uni-
versity's Best Teactler Award. He is also listed in Purdue's Book of Great Teachers. a
permanent wall display in the Purduc Memonial Union, dedicated on April 23. 1999.
The book bears the name of the inaugural group of 225 faculty members. past and
present, who have devoted their lives to excellence in teaching and scholarship. They
were chosen by their students and their peers as Purdue's finest educators.
A native of Los Angeles.California. John A. Buck received his M.S. and Ph.D.
degrees in Electrical Engineering from the University of California at Berkeley in
1977 and 1982. and his B.S. in Engineering from UCLA in 1973. In 1982. he joined
the faculty of the School of Electrical and Computer Engineering at Georgia Tech,
where he has remained for the past 28 years. His research areas and publications
have centered within the fields of ultratfast ,switching,nonlinear optics, and optical
fiber communications. Hc is the author of the graduate text Fundamentals of Optical
Fibers (Wiley Interscience ). which is now in its second edition. Awards include the
institute teaching awards and the IEEE Third Millenium Medal. When not glued to
his computer or confined to the lab, Dr. Buck enjoys music,hiking,and photography.
序
作者William H.Hayt,Jr.教授曾任教于美国普渡大学,其一生获得诸多荣誉,堪称教学名师之典范。请读者在学习该教材之前,一定要阅读作者简介,相信这一定会激发你对William H.Hayt,Jr.教授的敬仰和对电磁场学习的兴趣。作者J. A. Buck为乔治亚理工学院电气与计算机工程系教授。两位作者合编的该书的第6版于2001年出版,William,H.Hayt,Jr.的第1版距今已50多年。
本教材与国内电子与电气工程专业的本科教材基本一致,其内容满足我国高校教学大纲要求。该书基本概念讲述清晰、注重物理概念、淡化公式推导、图文并茂、定理和重要公式彩色加重印刷; 每章后面都配有约30道习题。该书写作文笔流畅、可读性好、易理解,学生可以使用该教材进行自主学习,是电磁场或电磁场与波课程的理想教材或参考书。
需要特别指出的是: 该书配有学习网站(网址见封底),网站提供了丰富的学习资源和内容,包括图、动画、互动、小测验等,书中页边处给出了网站上对应内容的图标,每当学到图标处时,建议查阅网站相应内容,这对学习非常有益。另外,每章后面的习题采用三级难度分类标识给出每道题的难易程度(题号后的竖条),便于不同学习程度的学生选择习题。
相对于国内相应教材,该书在内容上包含一些工程使用性内容,如不规则形状电极间的电容近似计算方法、PN结电容、磁路概念、铁磁材料的非线性等内容。该书在内容上的另一特点是简略一些公式推导,加强物理概念讲述,新版本更加如此。例如,新版本删除了求解拉普拉斯方程和泊松方程的分离变量法和差分法等内容,因为此为数学方法,并非物理概念。删除的这些内容放到了网站上供扩展性学习。
该书在内容编排上有独到之处。例如,在静电场部分,将能量与电位的引入结合在一起(第4章的题目为能量和电位),突出了电位是电场对单位电荷做功的物理属性,而不是像国内教材强调电位梯度等于电场强度的数学关系; 在磁场部分,相对于静电场部分的5章编排,该部分仅以两章出现,一章的题目为“恒定磁场”,另一章的题目为“磁场力、材料和电感”,这种编排的综合性与静电场内容编排的分散性形成了明显的反差,且在讲解中多处是通过与静电场类比的形式直接给出结果或结论。
在内容讲解上比较简洁,如仅用了两页就介绍完了磁场能量与求磁场力的虚功法,并且概念和实用性很强,从该节题目上的“磁材料上的力”便可以清楚地表明,虚功法的主要用途是求作用在磁材料上的力,这是利用洛伦兹磁力的表达式求解所不及的。
该书在教学网站提供了教辅资源,包括动画、互动、测验等,并给出了一些利用Ansoft等电磁场数值计算软件得到的场图,以及一些问答测试题。
袁建生
清华大学电机与应用电子技术系
2014年3月
PREFACE
It has been 52 years since the first edition of this book was published,then under the
sole authorship of William H. Hayt. Jr. As I was five years old at that time,this would
have meant little to me. But everything changed 15 years later when Iused the second
edition in a basic electromagnetics course as a college junior. I remember my sense
of foreboding at the start of the course. being aware of friends' horror stories. On first
opening the book. however, I was pleasantly surprised by the friendly writing style
and by the measured approach to the subject, which - at least for me - made it a
very readable book,out of which I was able to learn with little help from my professor.
I referred to it often while in graduate school,taught from the fourth and fifth editions
on the retirement(and subsequent untimely death)of Bill Hayt. The memories of my time as
a beginner are clear,and I have tried to maintain the accessible style that I found so welcome then.
Over the 50-year span,the subject matter has not changed. but emphases have. In
the universities,the trend continues toward reducing electrical engineering core course
allocations to electromagnetics. I have made efforts to streamline the presentation in
this new edition to enable the student to get to Maxwell's equations sooner,and I have
added more advanced material. Many of the earlier chapters are now slightly shorter
than their counterparts in the seventh edition. This has been done by economizing on
the wording, shortening many sections, or by removing some entirely. In some cases.
deleted topics have been convened to stand-alone articles and moved to the website,
from which they can be downloaded. Major changes include the following: (1) The
material on dielectrics.formerly in Chapter 6,has been moved to the end of Chapter 5.
(2) The chapter on Poisson's and Laplace's equations has been eliminated, retaining
only lhe one-dimensional trealment, which has been moved to the end of Chapter 6.
The two-dimensional Laplace equation discussion and that of numerical methods have
been moved to the website for the book. (3 ) The treatment on rectangular waveguides
(Chapter 13) has been expanded, presenting the methodology of two-dimensional
boundary value problems in that context. (4) The coverage of radiation and antennas
has been greatly expanded and now forms the entire Chapter 14.
Some 130 new problems have been added throughout. For some of these, I chose
particularly good “classic” problems from the earliest editions. I have also adopted
a new system in which the approximate level of difficulty is indicated beside each
problem on a three-level scale. The lowest level is considered a fairly straightforward
problem,requiring little work assuming the material is understood; a level 2 problem
is conceptually more difficult, and/or may require more work to solve; a level 3 prob-
lem is considered either difficult conceptually, or may require extra effort (including
possibly the help of a computer) to solve.
As in the previous edition, the transmission lines chapter (10) is stand-alone,
and can be read or covered in any part of a course, including the beginning. In
it, transmission lines are treated entirely within the context of circuit theory; wave
phenomena are introduced and used exclusively in the form of voltages and cur-
rents. Inductance and capacitance concepts are treated as known parameters. and
so there is no reliance on any other chapter. Field concepts and parameter com-
putation in transmission lines appear in the early part of the waveguides chapter
(13), where they play additional roles of helping to introduce waveguiding con-
cepts. The chapters on electromagnetic waves, 11 and 12, retain their independence
of transmission line theory in that one can progress from Chapter 9 directly to
Chapter 11. By doing this, wave phenomena are introduced from first principles
but within the context of the uniform plane wave. Chapter 11 refers to Chapter 10 in
places where the latter may give additional perspective, along with a little more detail.
Nevertheless, all necessary material to learn plane waves without previously studying
transmission line waves is found in Chapter 11, should the student or instructor wish
to proceed in that order.
The new chapter on antennas covers radiation concepts, building on the retarded
potential discussion in Chapter 9. The discussion focuses on the dipole antenna,
individually and in simple arrays. The last section covers elementary transmit-receive
systems, again using the dipole as a vehicle.
The book is designed optimally for a two-semester course. As is evident. statics
concepts are emphasized and occur first in the presentation, but again Chapter 10
(transmission lines) can be read first. In a single course that emphasizes dynamics,
the transmission lines chapter can be covered initially as mentioned or at any point in
the course. One way to cover the statics material more rapidly is by deemphasizing
materials properties (assuming these are covered in other courses) and some of the
advanced topics. This involves omitting Chapter 1 (assigned to be read as a review).
and omitting Sections 2.5, 2.6, 4.7, 4.8, 5.5-5.7, 6.3, 6.4, 6.7, 7.6, 7.7, 8.5, 8.6, 8.8,
8.9, and 9.5.
A supplement to this edition is web-based material consisting of the afore-
mentioned articles on special topics in addition to animated demonstrations and
interactive programs developed by Natalya Nikolova of McMaster University and
Vikram Jandhyala of the University of Washington. Their excellent contributions
are geared to the text, and icons appear in the margins whenever an exercise that
pertains to the narrative exists. In addition, quizzes are provided to aid in furrher
study.
The theme of the text is the same as it has been since the first edition of 1958.
An inductive approach is used that is consistent with the historical development. In
it, the experimental laws are presented as individual concepts that are later unified
in Maxwell's equations. After the first chapter on vector analysis, additional math-
ernatical tools are introduced in the text on an as-needed basis. Throughout every
edition, as well as this one, the primary goal has been to enable students to learn
independently. Numerous examples, drill problems (usually having multiple parts),
end-of-chapter problems, and material on the web site, are provided to facilitate this.
Answers to the drill problems are given below each problem. Answers to odd-
numbered end-of-chapter problems are found in Appendix F. A solutions manual
and a set of PowerPoint slides, containing pertinent figures and equations, are avail-
able to instructors. These,along with all other material mentioned previously, can be
accessed on the website:
www.mhhe.com/haytbuck
I would like to acknowledge the valuable input of several people who helped
to make this a better edition. Special thanks go to Glenn S. Smith (Georgia Tech),
who reviewed the antennas chapter and provided many valuable comments and sug-
gestions. Detailed suggestions and errata were provided by Clive Woods (Louisiana
State University), Natalya Nikolova, and Don Davis (Georgia Tech). Accuracy checks
on the new problems were carrieci out by Todd Kaiser (Montana State University)
and Steve Weis (Texas Christian University). Other reviewers provided detailed com-
ments and suggestions at the start of the project; many of the suggestions affected the
outcome. They include:
Sheel Aditya - Nanyang Technological University, Singapore
Yaqub M. Amani - SUNY Maritime College
Rusnani Ariffin - Universiti Teknologi MARA
Ezekiel Bahar - University of Nebraska Lincoln
Stephen Blank - New York Institute of Technology
Thierry Blu - The Chinese University of Hong Kong
Jeff Chamberlain - Illinois College
Yinchao Chen - University of South Carolina
Vladimir Chigrinov - Hong Kong University of Science and Technology
Robert Coleman - University of North Carolina Charlotte
Wilbur N. Dale
lbrahim Elshafiey - King Saud University
Wayne Grassel - Point Park University
Essam E. Hassan - King Fahd University of Petroleum and Minerals
David R. Jackson - University of Houston
Karim Y. Kabalan - American University of Beirut
Shahwan Victor Khoury, Professor Emeritus - Notre Dame University,
Louaize-Zouk Mosbeh, Lebanon
Choon S. Lee - Southern Methodist University
Mojdeh J. Mardani - University of North Dakota
Mohamed Mostafa Morsy - Southern Illinois University Carbondale
Sima Noghanian - University of North Dakota
W.D. Rawle - Calvin College
Goniul Sayan - Middle East Technical University
Fred H. Terry - Professor Emeritus. Christian Brothers University
Denise Thorsen - IJniversity of Alaska Fairbanks
Chi-Ling Wang - Feng-Chia University
I also acknowledge the feedback and many comments from students. too numerous to
name, including several who have contacted me from afar. I continue to be open and
grateful for this feedback and can be reached at john.buck@ece.gatech.edu. Many
suggestions were made that I considered constructive and actionable. I regret that
not all could be incorporated because of time restrictions. Creating this book was a
team effort, involving several outstanding people at McGraw-Hill. These include my
publisher, Raghu Srinivasan, and sponsoring editor, Peter Massar, whose vision and
encouragement were invaluable, Robin Reed,who deftly coordinated the production
phase with excellent ideas and enthusiasm, and Darlene Schueller. who was my
guide and conscience from the beginning, providing valuable insights, and jarring me
into action when necessary. Typesetting was supervised by Vipra Fauzdar at Glyph
International, who employed the best copy editor I ever had, Laura Bowman. Diana
Fouts (Georgia Tech) applied her vast artistic skill to designing the cover, as she has
done for the previous two editions. Finally, I am, as usual in these projects, grateful
to a patient and supportive family, and particularly to my daughter, Amanda. who
assisted in preparing the manuscript.
John A. Buck
Marietta, Georgia
December ,2010
On the cover: Radiated intensity patterns for a dipole antenna, showing the cases
for which the wavelength is equal to the overall antenna length (red), two-thirds the
antenna length (green), and one-half the antenna length (blue).