Asymptotic methods provide considerable physical insight and understanding of diffraction mechanisms and are very useful in the design of electromagnetic devices such as radar targets and antennas. However, difficulties can arise when trying to solve problems using multipole and asymoptotic methods together, such as in radar cross section objects. This new book offers a solution to this problem by combining these approaches into hybrid methods, therefore creating high demand for both understanding and learning how to apply asymptotic and hybrid methods to solve diffraction problems. The book provides the very latest and most comprehensive research on this subject.
Also available:
Electromagnetic Mixing Formulas and Applications - ISBN 9780852967720 Ferrites at Microwave Frequencies - ISBN 9780863410642
The Institution of Engineering and Technology is one of the world's leading professional societies for the engineering and technology community. The IET publishes more than 100 new titles every year; a rich mix of books, journals and magazines with a back catalogue of more than 350 books in 18 different subject areas including:
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Author(s): I. Andronov, D. Bouche F. Molinet
Series: IEE Electromagnetic Waves Series
Edition: illustrated edition
Publisher: Institution of Electrical Engineers
Year: 2005
Language: English
Pages: 263
City: London
Contents......Page 6
Preface......Page 10
1.1.1 General overview of the theory and basic concepts......Page 14
1.1.2 Fermat principle......Page 16
1.1.3 Fundamentals of asymptotic expansions......Page 21
1.1.4 Asymptotic solution of Maxwell’s equations in a source-free region......Page 24
1.1.5 Field reflected by a smooth object......Page 32
1.1.6 Field transmitted through a smooth interface between two different media with constant refractive indexes......Page 36
1.1.7 Field diffracted by the edge of a curved wedge......Page 40
1.1.8 Field in the shadow zone of a smooth convex object (creeping rays)......Page 44
1.2.1 Introduction......Page 46
1.2.2 Diffraction by a smooth convex body......Page 48
1.2.3 Parabolic equation......Page 49
1.2.4 Asymptotics of the field in the Fock domain......Page 50
1.2.5 Creeping waves......Page 53
1.2.6 Friedlander–Keller solution......Page 56
1.2.7 Boundary layer in penumbra......Page 58
1.2.8 Whispering gallery waves......Page 60
1.2.9 Wave field near a caustic......Page 61
1.2.10 Diffraction by a transparent body......Page 65
1.2.11 Conclusion......Page 68
1.3 Numerical examples......Page 69
1.4 References......Page 75
2.1.1 Introduction......Page 78
2.1.2 Equations and boundary conditions......Page 79
2.1.4 Derivation of the solution of Maxwell’s equations in the coordinate system (s, a, n)......Page 80
2.1.5 Interpretation of the equations associated with the first three orders......Page 83
2.1.6 Boundary conditions and the determination of p(s, a)......Page 85
2.1.7 Physical interpretation of the results......Page 92
2.1.8 Second-order term for the propagation constant......Page 94
2.1.9 Conclusion......Page 97
2.2.2 Creeping waves on an impedance surface with Z = O(1)......Page 99
2.2.3 Special case of the surface impedance Z =1......Page 105
2.2.4 Anisotropic impedance case......Page 107
2.2.5 Caustic of creeping rays......Page 110
2.3.1 Introduction......Page 114
2.3.2 The Ansatz and types of elongated objects......Page 115
2.3.3 Moderately elongated body......Page 116
2.3.4 Waves on strongly elongated bodies......Page 117
2.3.5 Numerical analysis......Page 123
2.4.1 Introduction......Page 124
2.4.2 Scalar waves......Page 125
2.4.3 Electromagnetic waves......Page 130
2.4.4 Excitation of waves at interfaces......Page 136
2.4.5 Numerical results......Page 138
2.5 References......Page 140
3.1 Introduction......Page 142
3.2 Spectral representation of the Fock field on a smooth surface......Page 144
3.3.1 Two-dimensional perfectly conducting wedge......Page 146
3.3.2 Three-dimensional wedge......Page 151
3.4 Hybrid diffraction coefficients for a curvature discontinuity......Page 156
3.5 Solution valid at grazing incidence and grazing observation......Page 157
3.5.1 Two-dimensional perfectly conducting wedge......Page 158
3.5.3 Curvature discontinuity......Page 164
3.6.1 Spectral representation of the Fock field on a smooth coated surface......Page 166
3.6.2 Hybrid diffraction coefficients for a coated 2D wedge......Page 168
3.6.3 Grazing incidence and observation on a coated 2D wedge......Page 170
3.7 Numerical results......Page 174
3.8 References......Page 175
4.1 Introduction......Page 178
4.2.1 Perfectly conducting surface......Page 179
4.2.2 Imperfectly conducting or coated surface......Page 181
4.2.3 Numerical calculation of the Fock functions......Page 182
4.3.1 Perfectly conducting convex surface delimited by sharp edges......Page 183
4.3.2 Imperfectly conducting or coated wedge with convex faces......Page 192
4.3.3 Improvement of the asymptotic currents close to theedge for a perfectly conducting wedge......Page 195
4.3.4 Numerical results......Page 196
4.4.1 Introduction......Page 200
4.4.2 Solution of the canonical problem of a line sourceparallel to the generatrix of a concave circular cylinder......Page 202
4.4.3 Transformation of the integral form of the solution......Page 207
4.4.5 Edge-excited currents on a perfectly conducting concave surface......Page 214
4.5 Three-dimensional perfectly conducting convex–concave surface......Page 216
4.6 Numerical results......Page 220
4.7 References......Page 222
5.1 Introduction – state-of-the-art......Page 224
5.1.1 A priori phase determination......Page 227
5.1.2 Analytically or asymptotically derived characteristic basis functions......Page 230
5.2 Equivalence theorem and its consequences......Page 231
5.2.1 Corollary 1......Page 232
5.2.3 Other forms of the equivalence theorem......Page 233
5.3 Application of the equivalence theorem to the hybridisation of the methods......Page 235
5.3.1 Cavity in a smooth perfectly conducting surface......Page 236
5.3.2 Protrusion standing out of a smooth perfectly conducting surface......Page 240
5.4.1 Cavity in a coated smooth surface......Page 245
5.4.2 Protrusion standing out of a coated regular surface......Page 248
5.5 Brief review of asymptotic solutions adapted to the development of hybrid methods......Page 249
5.6.1 Slotted ogival cylinder......Page 250
5.6.2 Rectangular cavity......Page 252
5.7 References......Page 257
Index......Page 260
