Electromagnetic Pulse Simulations Using Finite–Difference Time–Domain Method

✍ Scribed by Shahid Ahmed

• Publisher: Wiley
• Year: 2021
• Tongue: English
• Leaves: 355
• Edition: 1
• Category: Library

✦ Synopsis

Electromagnetic Pulse Simulations Using Finite-Difference Time-Domain Method

Discover the utility of the FDTD approach to solving electromagnetic problems with this powerful new resource

Electromagnetic Pulse Simulations Using Finite-Difference Time-Domain Method delivers a comprehensive overview of the generation and propagation of ultra-wideband electromagnetic pulses. The book provides a broad cross-section of studies of electromagnetic waves and their propagation in free space, dielectric media, complex media, and within guiding structures, like waveguide lines, transmission lines, and antennae.

The distinguished author offers readers a fresh new approach for analyzing electromagnetic modes for pulsed electromagnetic systems designed to improve the reader’s understanding of the electromagnetic modes responsible for radiating far-fields. The book also provides a wide variety of computer programs, data analysis techniques, and visualization tools with state-of-the-art packages in MATLAB^® and Octave.

Following an introduction and clarification of basic electromagnetics and the frequency and time domain approach, the book delivers explanations of different numerical methods frequently used in computational electromagnetics and the necessity for the time domain treatment. In addition to a discussion of the Finite-difference Time-domain (FDTD) approach, readers will also enjoy:

• A thorough introduction to electromagnetic pulses (EMPs) and basic electromagnetics, including common applications of electromagnetics and EMP coupling and its effects
• An exploration of time and frequency domain analysis in electromagnetics, including Maxwell’s equations and their practical implications
• A discussion of electromagnetic waves and propagation, including waves in free space, dielectric mediums, complex mediums, and guiding structures
• A treatment of computational electromagnetics, including an explanation of why we need modeling and simulations

Perfect for undergraduate and graduate students taking courses in physics and electrical and electronic engineering, Electromagnetic Pulse Simulations Using Finite-Difference Time-Domain Method will also earn a place in the libraries of scientists and engineers working in electromagnetic research, RF and microwave design, and electromagnetic interference.

✦ Table of Contents

Cover
Title Page
Copyright
Contents
Acknowledgments
Preface
Chapter 1 Electromagnetic Pulse
1.1 Sources of EMP
1.2 EMP Coupling and its Effects
1.3 EMP Simulators
1.4 Review of Earlier Work
1.5 Overview of this Book
1.6 Summary
Chapter 2 Time and Frequency Domain Analysis
2.1 Introduction
2.2 Nuclear Electromagnetic Pulse
2.2.1 Differences of Two Exponentials Times in a Unit Step Function
2.2.1.1 Time‐Domain
2.2.1.2 Frequency‐Domain
2.2.2 Reciprocal of the Sum of Two Exponentials
2.2.2.1 Time‐Domain Characteristics
2.2.2.2 Frequency‐Domain
2.3 Summary
Chapter 3 Simulations Using FDTD Method
3.1 Introduction
3.2 Need for FDTD Analysis of an EMP Simulator
3.2.1 Choice of Method for Self‐consistent Analysis
3.3 Maxwell's Equations and the Yee Algorithm
3.4 FDTD Implementation
3.5 Numerical Issues
3.6 Summary
Chapter 4 Electromagnetic Pulse in Free Space and Material Media
4.1 Introduction
4.2 Input Waveform
4.2.1 MATLAB® Script for Visualization: Listing #1
4.2.2 Execution of MATLAB/OCTAVE Code
4.3 One‐dimension Approach
4.3.1 Free Space
4.3.1.1 MATLAB Code Listing #1: EM Wave Propagation in Free‐space
4.3.2 Data Recording and Visualization
4.3.2.1 MATLAB Script for Visualization: Listing #2
4.3.3 Dielectric Medium
4.3.3.1 Lossless Dielectric Medium
4.3.3.2 MATLAB Code Listing #2: EM Wave in Air and Lossless‐dielectric Medium
4.3.3.3 Lossy Dielectric Medium
4.3.3.4 MATLAB Code Listing #3: EM Wave in Air and Lossy‐dielectric Medium
4.3.3.5 MATLAB Code Listing #4: Analytical Approach for Wave in Lossy Medium
4.3.4 Perfect Electric Conductor (PEC)
4.3.4.1 MATLAB Code Listing #5: EM Wave in Air‐PEC Half‐space
4.4 Summary
Exercises
Chapter 5 Simulation of Capacitor Bank
5.1 Introduction
5.2 Details of Model
5.2.1 Description of Geometry
5.2.2 Method of Charging
5.2.3 Method for Calculating FDTD Charge and Capacitance
5.2.4 FDTD Model of Closing Switch
5.2.5 Discharging a Charged Capacitor
5.3 Results and Discussion
5.3.1 Charge Deposition on Plates
5.3.2 Stabilization of Charge Density Distribution
5.3.3 Determination of Characteristic Discharge Time
5.4 Cross‐check of FDTD Results Using Method‐of‐Moments
5.4.1 Check of Capacitance
5.4.2 Edge Effects on Charge Density Distribution
5.4.3 Check of Charge Density Distribution
5.5 Effect of Boundary Condition
5.6 Summary
Exercises
Chapter 6 Bounded Wave Simulator for Electromagnetic Pulses
6.1 Introduction
6.1.1 Organization of This Chapter
6.2 Geometry and Computational Model
6.2.1 Idealizations
6.2.2 Geometry
6.2.3 FDTD Model
6.3 Validation of TEM Structure Geometry
6.3.1 Analytical Check
6.3.2 Numerical Check
6.4 FDTD Model of Closing Switch
6.5 Choice of Distance to Domain Boundary
6.6 Electric Field within TEM Structure
6.6.1 Effect of Switch Closure Time
6.6.2 Pulse Fidelity
6.7 Flow of Current through Simulator Plates
6.8 Prepulse
6.9 Effect of Test Object
6.10 Validation Checks for FDTD Analysis
6.11 Summary
Exercises
Chapter 7 Electromagnetic Modes Inside Bounded Wave Simulators
7.1 Introduction
7.1.1 Choice of Method for Modal Analysis
7.1.2 Organization of This Chapter
7.2 Details of Model
7.2.1 FDTD Model
7.2.2 Qualitative Discussion of Mode Structure
7.2.3 Application of SVD for Modal Analysis
7.2.4 Validation of SVD Results
7.2.5 Sample Calculation
7.3 Modal Analysis of Simulator Without Test Object
7.4 Modal Analysis of Simulator With Test Object
7.4.1 Qualitative Analysis
7.4.2 Quantitative Analysis Using SVD of Ex Data
7.4.3 Quantitative Analysis Using SVD of Ez Data
7.5 Physical Interpretation for Electric Field Increase
7.6 Summary
Exercises
Chapter 8 Parametric Study of Radiation Leakage from a Bounded‐Wave Simulator
8.1 Introduction
8.2 Details of Computational Model
8.3 Sensitivity to Length of Parallel‐plate Extension
8.4 Sensitivity to Angle Between Tapered Plates
8.5 Effect of Type of Termination
8.6 Sensitivity to Closure Time of Switch
8.7 Effect of Test Object
8.8 Physical Interpretation
8.9 Summary
Exercises
Chapter 9 Modal Perspective of Radiation Leakage from a Bounded‐Wave Simulator
9.1 Introduction
9.2 Calculation Procedure
9.3 Effect of Angle of Inclination Between Tapered Plates
9.3.1 Correlation Study
9.3.2 Physical Interpretation
9.3.3 Variation of Leakage with Plate Angle
9.4 Effect of Pulse Compression
9.4.1 Effect on Radiation Leakage
9.4.2 Explanation in Terms of Mode Structure
9.5 Summary
Exercises
Chapter 10 Spatial Mode Filter for Reducing Radiation Leakage
10.1 Introduction
10.2 Suppression of Higher Order Modes
10.2.1 Optimal Value of Longitudinal Resistance
10.2.2 Optimal Length of Suppressor Inside Test Volume
10.2.3 Mode Structure with Suppressor in Presence of Test Object
10.3 Summary
Exercises
Chapter 11 EMP Interaction with Biological Tissues
11.1 Introduction
11.2 Model Description
11.3 Results and Discussion
11.3.1 Pulse Evolution in the TEM Cell
11.3.2 Interaction of EMP with Human Body
11.4 Summary
Exercises
Chapter 12 FDTD Computer Program
12.1 Introduction
12.2 Computer Code Details
12.3 Sample Output
12.4 Summary
References
Index
EULA