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The Use of Software Learning Tools in Electromagnetic Education
Gregory M. Wilkins, Ph.D. Morgan State University
Although the concept of electromagnetics is one of the most historical topics taught in electrical engineering curricula, it is often met with fear and uncertainty. Far too often students are intimidated prior to enrolling in the class, with reservations about the mathematical requirements and the alleged physical abstraction of the course. Frequently students complain about the course having few, if any, laboratory components. Another complaint is the inability to relate the topics to any application which may be considered as practical. Students commonly indicate that it is easier to understand the concept of current flow and electric potential difference than to understand electromagnetic field behavior. It must be stressed that, although one can measure the amount of current flowing in a portion of an electrical network, or measure the electric potential difference between two points in the network, these measurements simply reflect the effects due to electromagnetic interactions within the elements which make up the network. The measurements do not illustrate any type of electron motion, or allow the experimenter to more easily view any differences in potential energy associated with a voltage measurement. Students are nonetheless convinced that something is occurring, due to the hands-on nature of the course material. It is not quite so easy to get students to accept the behavior of electromagnetic fields. This is largely due to the fact that the subject is taught mostly from a mathematical point of view. As a result, students very often get lost in the equations. A relatively strong mathematical background is required in order for the full appreciation to be given to the subject matter. Otherwise, students will indicate that the course was merely a stepping stone in their education. Even students and professionals who have been quite successful in the completion of the course will suggest that physical understanding is lacking. Many texts have been written on the study of electromagnetics, [1]-[24], with a variety of opinions as to the best approach. However, one point upon which most scientists and engineers commonly agree is the need for some type of visualization tool in order to put into perspective the data obtained from the vast number of electromagnetic equations. Electromagnetics has traditionally been very useful in telecommunications and in military applications such as navigational guidance and radar. However, many areas such as power transmission, electronic packaging, microwave device design and characterization, photonics, and optoelectronics all rely heavily on the governing principles of electromagnetics. By making students aware of these direct applications, interest may be stimulated in the study of these topics. This is where visualization of the field behavior is essential. Other tools may be available and may be useful for manipulation of the equations governing electromagnetic behavior, but these provide little or no insight into the physical behavior. It is true that students may encounter difficult mathematical procedures such as integration and differentiation, or may be required to make approximations. But without a firm understanding of the connection between the equations and the thought processes leading to their inception, or at least a realization that the equations do actually represent natural occurrences, equation manipulation is meaningless. Tools such as MATLAB[25], Mathematica[26], Maple[27], and MathCad[28] are very helpful in symbolic and numerical solutions, and even provide graphical tools. However, these tools do not provide a method for interpreting the results for the user who is not experienced in this subject matter. Students should have a mechanism of self-assessment to determine the degree of their understanding. This approach may be difficult at the introductory level of an electromagnetics course. As a result, several efforts have been made to develop software packages which enable students to visualize electromagnetic phenomena and directly relate them to the corresponding mathematical relations. In particular, packages from the Applied Electromagnetics Group from the University of Victoria [29] and the Center of Excellence for Multimedia Education and Technology (CAEME) [30] University of Utah have proven to be very useful. Both packages provide fundamental tutorial information, along with interactive exercises and follow-up quizzes to track student progress. Other commercially available software [31] and information provided from national laboratories and universities [32]- [40], illustrating the propagation of electromagnetic waves are available as resources to students.
Conclusions: As this approach is still in the preliminary stages at Morgan State University, we hope to enhance the education of undergraduate students to the point that they become active in the application of electromagnetics to current research topics. An understanding of the material could subsequently lead to a reputable electromagnetics education and research environment. Some of our objectives will be as follows: 1. Develop student understanding of electromagnetic wave propagation and energy transmission. 2. Provide pertinent literature and hold discussions necessary for background development.
6. Obtain iterative and direct solvers, and run comparison tests as applied to large problems which are frequently encountered in computational electromagnetics problems.
With this type of exposure to both visualization of field and wave behavior students will learn to appreciate the topics studied in electromagnetics for their historical significance as well as for their applications to modern-day problems.
Bibliography
[1] D. H. Staelin, A. W. Morgenthaler, J. A. Kong, Electromagnetic Waves, Prentice-Hall, 1994. [2] N. N. Rao, Elements of Engineering Electromagnetics, Fifth Edition, Prentice-Hall, 2000. [3] J. D. Kraus, Electromagnetics, Fifth Edition, McGraw-Hill Inc., 1999. [4] S. E. Schwarz, Electromagnetics for Engineers, Holt, Rinehart, and Winston, Inc., 1990.
[7] D. K. Cheng, Field and Wave Electromagnetics, Second Edition, Addison-Wesley, 1989. [8] D. K. Cheng, Fundamentals of Engineering Electromagnetics, Addison-Wesley, 1993. [9] F. T. Ulaby, Fundamentals of Applied Electromagnetics, Media Edition, Prentice Hall, 2001. [10] P. Aaron, W. N. Taberner, Circuits & Fields, a first course, Prentice Hall, 1995. [11] S. Ramo, J. R. Whinnery, T. Van Duzer, Fields and Waves in Communications Electronics, Third Edition, John Wiley & Sons, Inc., 1994. [12] M. A. Plonus, Applied Electromagnetics, McGraw-Hill, Inc., 1978. [13] S. R. H. Hoole , P. R. P. Hoole, A Modern Short Course in Engineering Electromagnetics, Oxford University Press, 1996. [14] G. F. Miner, Lines and Electromagnetic Fields for Engineers, Oxford University Press, 1996. [15] C. R. Paul, S. A. Nasar, K. W. Whites, Introduction to Electromagnetic Fields, Third Edition, McGraw-Hill, 1998. [16] S. V. Marshall, R. E. DuBroff, G. G. Skitek, Electromagnetic Concepts and Applications, Fourth Edition, Prentice Hall, 1996. [17] M. F. Iskander, Electromagnetic Fields & Waves, Prentice Hall, 1992. [18] B. S. Guru, H. R. Hiziroglu, Electromagnetic Field Theory Fundamentals, PWS Publishing Company, Inc., 1998. [19] P. Hammond, Electromagnetism for Engineers: An Introductory Course, Fourth Edition, Oxford University Press, 1997. [20] K. R. Demarest, Engineering Electromagnetics, Prentice Hall, Inc, 1998. [21] U. Inan, A. Inan, Engineering Electromagnetics, Addison Wesley, Inc, 1999. [22] Z. Popovic and B. D. Popovic, Introductory Electromagnetics, Prentice Hall Inc, 2000. [23] U. Inan, A. Inan, Electromagnetics Waves, Prentice-Hall Inc, 2000. [24] P. Diament, Dynamic Electromagnetics, Prentice Hall Inc, 2000.
[29] http://www.bioelec.ece.uvic.ca/index.html [30] http://www.caeme.elen.utah.edu/
[32] http://emlib.jpl.nasa.gov/ [33] http://ostc.physics.uiowa.edu/~wkchan/EM/PROGRAMS/POLARIZATION/ [34] http://home.a-city.de/walter.fendt/physengl/emwave.htm [35] http://www.universityphysics.com/em_wave1.html [36] http://www.ee.iastate.edu/~hsiu/em_movies.html [37] http://www.glenbrook.k12.il.us/gbssci/phys/mmedia/waves/em.html [38] http://www.colorado.edu/physics/2000/waves_particles/ [39] http://micro.magnet.fsu.edu/primer/java/electromagnetic/ [40] http://www.phy.ntnu.edu.tw/~hwang/emWave/emWave.html
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