Charge Acceleration and the Spatial Distribution of Radiation Emitted by Antennas and Scatterers (Electromagnetic Waves)

Cover
Contents
Journal articles and book chapters that are related to electromagnetic radiation by the author and his colleagues
About the author
Dedication
Presentations
Preface
Introduction
1 Overview
	1.1 Introduction
	1.2 The electric-field kink model of electromagnetic radiation
	1.3 The proportionality between charge acceleration and radiation from a generic wire object
	1.4 Time-domain energy measures
	1.5 The dependence of time-domain radiation loss on the circumference and wire radius of a circular loop
	1.6 The differentiated on- surface Poynting vector as a measure of radiation loss from wires
	1.7 Time-domain far-field analysis of radiation sources (TDFARS) and TWTD
	1.8 Frequency-domain far-field analysis of radiation sources (FDFARS) and NEC
	1.9 A comparison of time-domain and frequency-domain FARS
	1.10 An examination of the radiation properties of specified currents
	1.11 Development and comparison of the incremental FARS (IFARS) and incremental IEMF (IIEMF) methods
	1.12 The Schelkunoff–Feldman radiation resistance
	1.13 Comparison of the radiation properties of a sinusoidal current filament and a PEC dipole of near-zero radius
	1.14 The incremental FAR field and degrees of freedom of the sinusoidal current filament
	1.15 Appendix A
	1.16 Appendix B
	References
2 The electric-field kink model of electromagnetic radiation
	2.1 Introduction
		2.1.1 The propagation speed of EM fields is finite
		2.1.2 Electric lines of force are continuous
	2.2 The "KINK" model of radiation
	2.3 Some simple charge motions that produce radiation
		2.3.1 An abrupt start and stop
		2.3.2 A charge abruptly stopped
		2.3.3 A charge given a constant push
		2.3.4 A charge moving at constant speed around a circle
		2.3.5 A charge moving at constant speed around a square
		2.3.6 A charge undergoing oscillatory motion
		2.3.7 The effect of increasing speed on an oscillating charge
	2.4 How field lines close on a physical antenna
	2.5 Summary
	References
3 Charge-acceleration and radiation from a generic wire object
	3.1 Introduction
	3.2 Charge reflection and radiation
	3.3 A preview of radiation and current decay for a straight wire
	3.4 Comparing current decay on a long wire and circular loop
	3.5 Source-region radiation
	3.6 Propagation radiation
	3.7 Reflection radiation from the end of a wire
	3.8 Reflection radiation from resistive loads
	3.9 Radiation from directional reflection at a 90-deg bend
	3.10 Reflection radiation from a step in the wire radius
	3.11 An energy measure that demonstrates radiation loss
	3.12 Summary of the derived AFs
	3.13 Summary
	References
4 Time-domain electromagnetic-field energy measures
	4.1 Introduction
	4.2 Stored-energy measures
	4.3 Implementation of time-domain energy measures
	4.4 Some additional examples of TDEMs
	4.5 Summary
	References
5 Radiation-loss dependence of a circular loop antenna on its circumference and wire radius
	5.1 Introduction
	5.2 Numerical results for the loop antenna
		5.2.1 Varying the loop circumference
		5.2.2 Varying the loop wire radius
	5.3 Comparing a loop and straight wire
	5.4 Summary
	References
6 Differentiating the on- surface Poynting vector of a wire to determine its radiation loss
	6.1 Introduction: current decay and propagation radiation in the frequency domain
		6.1.1 Current decay and charge reflection in the frequency domain
	6.2 A preview of frequency-domain FARS
	6.3 Power flow near a straight- wire antenna
		6.3.1 The PV
		6.3.2 Power flow near a PEC wire
	6.4 FARS and differentiated-PV (DPV) results for a dipole antenna
	6.5 FARS and DPV results for a transmission-line driven dipole antenna
	6.6 FARS and DPV results for a straight-wire scatterer
		6.6.1 FARS and the DPV for a 10-wavelength wire scatterer at normal incidence
		6.6.2 FARS and the DPV for a 10- wavelength scatterer at near-axial incidence
		6.6.3 The near-interaction field on a straight-wire scatterer
	6.7 FARS and DPV results for some other thin-wire antennas
		6.7.1 A dipole with two right-angle bends
		6.7.2 A circular loop antenna
		6.7.3 A square loop antenna
		6.7.4 A zigzag antenna
	6.8 Summary
	Acknowledgment
	References
7 Time- domain far-field analysis of radiation sources and TWTD
	7.1 Introduction
		7.1.1 The perfect electric conductor as a radiator
		7.1.2 Why does radiation occur?
		7.1.3 Charge acceleration on a perfect electric conductor excited as an antenna
	7.2 Time-domain FARS (TDFARS)
	7.3 Validating time-domain FARS
	7.4 Some representative applications of TDFARS
		7.4.1 Radiation from straight wires
		7.4.2 Scattering from straight wires
		7.4.3 Radiation from loops
	7.5 The effect of varying the source location
	7.6 How charge reflection causes the FARS energy distribution
	7.7 Summary
	Appendix A: The occurrence of negative linear-power and -energy results from FARS
	Acknowledgment
	References
8 Frequency-domain far-field analysis of radiation sources and NEC
	8.1 Introduction
	8.2 Some background
	8.3 The FARS approach
	8.4 The induced electromotive force method
	8.5 Tangential electric fields of the sinusoidal current filament
	8.6 Initial FDFARS results for the sinusoidal current filament
	8.7 FDFARS results for straight wires
	8.8 FDFARS results for wire loops
	8.9 FDFARS results for arrays
	8.10 Other geometries
	8.11 A more complex geometry
	8.12 Summary
	References
9 Time- domain FARS and frequency- domain FARS compared
	9.1 Comparison of time-domain and frequency-domain far-field analysis of radiation sources
	9.2 Results for straight wires
	9.3 Results for wire loops
	9.4 The transmission-line excited dipole antenna
	9.5 A dipole enclosed by a wire cage
	9.6 Summary
	References
10 The radiation properties of some specified currents
	10.1 Introduction
	10.2 Using the IEMF method to analyze radiation from the SCF
	10.3 Results for other specified currents
	10.4 The Schelkunoff–Feldman distributed radiation resistance
	10.5 Summary
	References
11 The incremental FARS (IFARS) and incremental IEMF (IIEMF) methods
	11.1 Some background
	11.2 Generalizing the IEMF method
	11.3 FARS and its incremental version
		11.3.1 The basic frequency-domain FARS
		11.3.2 Incremental FARS
	11.4 The incremental IEMF method
	11.5 Numerical results
	11.6 Discussion
	11.7 Summary
	References
12 The Schelkunoff–Feldman radiation resistance
	12.1 Discussion and extension
	12.2 Summary
13 Radiation from a near-zero-radius dipole and a sinusoidal current filament
	13.1 Introduction
	13.2 Ways in which the SCF and PEC dipole are similar
		13.2.1 Total radiated power as a function of current length
		13.2.2 Radiation pattern
		13.2.3 Linear power density
		13.2.4 Schelkunoff–Feldman distributed radiation resistance
	13.3 Ways in which the SCF and PEC dipole are different
		13.3.1 Current distributions
		13.3.2 Time-average Poynting vectors parallel to the currents
		13.3.3 Tangential electric fields
		13.3.4 Distributions of induced EMF power
	13.4 The different radiation mechanisms for the near-zero-radius dipole and the sinusoidal current filament
		13.4.1 Radiation from the sinusoidal current filament
		13.4.2 Radiation from the PEC dipole
	13.5 Summary
	References
14 The pattern rank and spatial radiation distribution of radiation emitted by a sinusoidal current filament
	14.1 Introduction
	14.2 The far field of the SCF
	14.3 The implications of numerically evaluating the far field
	14.4 Examination of the far-field analytical expression
	14.5 Examination of numerically evaluating the far field
	14.6 The degrees of freedom of various patterns
	14.7 Current and charge relationship to radiation
	14.8 Summary
	References
Appendix A: The thin- wire time- domain (TWTD) computer code
Appendix B: The Numerical Electromagnetics Code (NEC)
Appendix C: Notation
Index
Back Cover