The finite difference time domain (FDTD) approach is rapidly becoming one of the most widely used computational methods in electromagnetics. There are several reasons for this, including the increased availability of low cost but powerful computers, and increasing interest in electromagnetic interactions with complicated geometries, which include penetrable dielectric and/or magnetic materials. Just as important perhaps is the extreme simplicity of the method. The fundamentals of FDTD can be grasped easily by undergraduate students, more easily than traditional frequency-domain approaches to electromagnetics. Yet FDTD is capable of computing electromagnetic interactions for problem geometries that are extremely difficult to analyze by other methods. It is this combination of simplicity and power that makes FDTD such a popular method.
This also allows this book to serve a wide range of potential readers. It can be used to introduce undergraduate students to time domain electromagnetics, in which case only the first two parts of the book need be covered. It can be used in a graduate level course, in which case the mathematical basis of FDTD would be emphasized with topics selected from the sections on special capabilities and advanced applications at the discretion of the instructor. Finally, someone who wants to use FDTD to solve a particular problem in electromagnetics can use the book to learn FDTD basics and special capabilities necessary for their application. In addition, it can be seen, through the examples in this book, how FDTD has been applied to a variety of problems.
The goals of the book are to provide the basic information necessary to apply FDTD to problems in electromagnetics, and to illustrate some of the types of problems that can be analyzed using it. The theoretical and mathematical basis for much of FDTD is included, but the emphasis is on the practical aspects of applying FDTD.
Author(s): Karl S. Kunz; Raymond J. Luebbers
Edition: 1
Publisher: CRC Press
Year: 1993
Language: English
Commentary: Paginated, cleaned, re-OCRed version of the DJVU version.
Pages: 448
City: Boca Raton
== Chapter 1. Introduction 1
=== PART 1: Fundamental Concepts
== Chapter 2. Scattered Field FDTD Formulation 11
2.1 Maxwell Curl Equations 11
2.2 Separate Field Formalism 12
2.3 Perfect Conductor FDTD Formulation 16
2.4 Perfect Conductor FDTD FORTRAN Code 19
2.5 Lossy Material Formulation 20
2.6 Lossy Dielectric FDTD FORTRAN Code 22
2.7 FDTD Code Requirements and Architecture 24
References 27
== Chapter 3. FDTD Basics 29
3.1 Introduction 29
3.2 Determining the Cell Size 30
3.3 Time Step Size for Stability 32
3.4 Specifying the Incident Field 33
3.5 Building an Object in Yee Cells 37
3.6 Direct Computation of Total Fields 42
3.7 Radiation Boundary Condition 43
3.8 Resource Requirements 46
References 49
=== PART 2: Basic Applications
== Chapter 4. Coupling Effects 53
4.1 Introduction 53
4.2 Electromagnetic Pulse 54
4.3 Exterior Pulse Response 55
4.3.1 Measurement Facility 55
4.3.2 FDTD Model of the Aircraft 56
4.3.3 Comparison of Predictions and Measurements 58
4.4 Interior Electromagnetic Shielding 61
4.4.1 Frequencies Above Aperture Cutoff 62
4.4.2 Frequencies Below Aperture Cutoff 70
References 76
== Chapter 5. Waveguide Aperture Coupling (Article by P. Alinikula and K. S. Kunz) 79
5.1 Introduction 79
5.2 Approach 79
5.3 Results 81
5.4 Conclusion 84
Acknowledgement 85
References 85
== Chapter 6. Lossy Dielectric Scattering 87
6.1 Introduction 87
6.2 Interpretation of the Scattered Field Method 87
6.3 Near Zone Sphere Scattering 90
6.3.1 Incident Field 90
6.3.2 Special Notes 90
6.3.3 Predictions 91
6.4 Human Body Absorption 91
References 101
=== PART 3: Special Capabilities
== Chapter 7. Far Zone Transformation 105
7.1 Introduction 105
7.2 Three-Dimensional Transformation 107
7.3 Two-Dimensional Transformation 113
7.4 Summary 118
References 122
== Chapter 8. Frequency-Dependent Materials 123
8.1 Introduction 123
8.2 First Order Debye Dispersion 124
8.3 First Order Drude Dispersion 131
8.4 Second Order Dispersive Materials 139
8.5 Multiple Poles 146
8.6 Differential Method 151
8.7 Scattered Field Formulation 154
References 161
== Chapter 9. Surface Impedance 163
9.1 Introduction 163
9.2 Constant Parameter Materials 166
9.3 Frequency-Dependent Materials 169
9.4 Recursive Evaluation 172
9.5 Demonstrations 175
References 183
== Chapter 10. Subcellular Extensions 185
10.1 Introduction 185
10.2 Integration Contours 185
10.3 Thin Wires 188
10.4 Lumped Circuit Elements 190
10.5 Expansion Techniques 194
10.6 Code Requirements, Limitations, and Utility 199
References 200
== Chapter 11. Nonlinear Loads and Materials 203
11.1 Introduction 203
11.2 Antenna with Nonlinear Diode 204
11.3 Nonlinear Magnetic Sheet 216
References 229
== Chapter 12. Visualization 231
12.1 Introduction 231
12.2 Types of Visualization 231
12.3 Examples 234
12.3.1 Model Fidelity 234
12.3.2 Model Response 234
12.3.3 Physical Process Insight 235
12.3.4 Intuition Building 235
12.4 Resources and Cost of Visualization 237
References 238
=== PART 4: Advanced Applications
== Chapter 13. Far Zone Scattering 241
13,1 Introduction 241
13.2 Fundamentals 243
13.3 Staircase Errors 244
13.4 Impedance Sheets 251
13.5 Distance to Outer Boundary 254
13.6 Frequency-Dependent Materials 259
References 261
== Chapter 14. Antennas 263
14.1 Introduction 263
14.2 Impedance, Efficiency, and Gain 265
14.3 Monopole Antenna on a Conducting Box 279
14.4 Shaped-End Waveguide Antenna 290
References 297
== Chapter 15. Gyrotropic Media 299
15.1 Introduction 299
15.2 Magnetized Plasma 299
15.3 Magnetized Ferrites 308
References 322
=== PART 5: Mathematical Basis of FDTD and Alternate Methods
== Chapter 16. Difference Equations in General 327
16.1 Introduction 327
16.2 Differencing Schemes for Hyperbolic Equations 330
16.3 Permutations on the Leapfrog Technique 333
References 334
== Chapter 17. Stability, Dispersion, Accuracy 335
17.1 Introduction 335
17.2 Stability 336
17.3 Numerical Dispersion 339
17.4 Accuracy 345
References 346
== Chapter 18. Outer Radiation Boundary Conditions 347
18.1 Introduction 347
18.2 Evolution of ORBCs 348
18.3 Mur Outer Radiation Boundary Condition 349
18.4 Alternate Formulations of the One-Way Wave Equations 356
References 358
== Chapter 19. Alternate Formulations 359
19.1 Introduction 359
19.2 Total Field Formation 359
19.3 Potential Formulation 360
19.4 Implicit Schemes 363
19.5 High Frequency Approximation 363
19.5.1 Time Domain Smythe-Kirchhoff Aperture Approximation and Method of Images for High FDTD Frequency Modeling 363
19.6 Acoustic Analog/Scalar Equivalent 365
19.6.1 Equation of Motion 365
19.6.2 Gas Law 366
19.6.3 Continuity Equation 366
References 367
Appendix A. Other Coordinate Systems and Reduced Dimensions 369
Introduction 369
3-D Cylindrical and Spherical 370
2-D Cylindrical 383
1-D Cartesian and Cylindrical 386
References 389
Appendix B. FORTRAN Listings 391
Description 391
FDTDA.FOR 391
COMMONA.FOR 424
DIAGS3D.DAT 426
NZOUT3D.DAT427
