Modern Antennas

649 Pages·1998·11.78 MB·English

by  S. Drabowitch

Modern Antennas
Microwave and RF Technology Series
The Microwave and RF Technology Series publishes authoritative works for
professional engineers, researchers and advanced students across the entire
range of microwave devices, sub-systems, systems and applications. The
series aims to meet the reader's needs for relevant information useful in
practical applications. Engineers involved in microwave devices and circuits,
antennas, broadcasting communications, radar, infra-red and avionics will find
the series an invaluable source of design and reference information.
Series editors:
Hugh Griffiths
Professor and Head of Microwaves, Radar and Optics Group, University
College London, UK
Fellow of the lEE and Senior Member of the IEEE
Bradford L. Smith
Senior Intellectual Property Counsel and Engineer, Corporate Research
Centre, Alcatel Alsthom, Paris, France
Senior Member of the IEEE and French SEE
TItles available
The Microwave Engineering Infrared Thermography
Handbook Volume 1 G. Gaussorgues
Microwave components
Edited by Bradford L. Smith and Phase Locked Loops
Michel-Henri Carpentier J. B. Encinas
The Microwave Engineering Frequency Measurement and Control
Handbook Volume 2 Chronos Group
Microwave circuits, antennas and
propagation Microwave Integrated Circuits
Edited by Bradford L. Smith and Edited by I. Kneppo
Michel-Henri Carpentier
Microwave Tube Transmitters
The Microwave Engineering L. Sivan
Handbook Volume 3
Microwave systems and applications Microwave ElectroDic Devices
Edited by Bradford L. Smith and Theo G. van de Roer
Michel-Hemi Carpentier
Introduction to Av ioDies
Solid-state Microwave Generation R. P. G. Collinson
J. Anastassiades, D. Kaminsky,
E. Perea and A. Poezevara
Modern Antennas
S. Drabowitch
Ecole Superieure d'Electricite, France
A. Papiernik
University of Nice-Sophia Antipolis, France
H. Griffiths
University College London, UK
and J. Encinas
formerly of the Institut Superieure d'Electronique de Paris, France
Edited by
H. Griffiths
(as above)
and Bradford L. Smith
Alcatel Alsthom, Paris, France
junj
SPRINGER-SCIENCE+BUSINESS MEDIA, BV.
First edition 1998
© 1998 S. Drabowitch, A. Papiemik, H. Griffiths, 1. Encinas and B. L. Smith
Originally published by Chapman & Hall in 1998
Softcover reprint of the hardcover 1s t edition 1998
ISBN 978-1-4757-2760-9 ISBN 978-1-4757-2758-6 (eBook)
DOI 10.1007/978-1-4757-2758-6
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A catalogue record for this book is available from the British Library
r§l
Printed on permanent acid-free text paper, manufactured in accordance with
ANSIINISO Z39.48-1992 and ANSIINISO Z39.48-1984 (permanence of Paper).
Contents
List of contributors xv
Foreword xvi
Acknowledgements xvii
1 Fundamentals of electromagnetism 1
1.1 Maxwell's equations 1
1.1.1 Maxwell's equations in an arbitrary medium 1
1.1.2 Linear media 4
1.1.3 Conducting media 6
1.1.4 Reciprocity theorem 8
1.2 Power and energy 10
1.2.1 Power volume densities 10
1.2.2 Energy volume densities 10
1.2.3 Poynting vector and power 11
1.3 Plane waves in linear media 12
1.3.1 Plane waves in an isotropic linear medium 12
1.3.2 Skin effect 18
Further reading 20
Exercises 21
2 Radiation 25
2.1 Plane wave spectrum 25
2.1.1 Spectral domain 26
2.1.2 Electromagnetic field in a semi-infinite space with no sources 28
2.1.3 The far field 33
2.2 Kirchhoff's formulation 38
2.2.1 Green's identity and Green's functions 38
2.2.2 Kirchhoff's integral formulation 39
2.2.3 Plane wave spectrum and Kirchhoffs formulation 42
Further reading 43
Exercises 44
3 Antennas in transmission 46
3.1 Far field radiation 46
3.1.1 Vector characteristic of the radiation from the antenna 46
3.1.2 Translation theorem 47
3.1.3 Application: radiation produced by an arbitrary current 48
3.1.4 Radiated power 51
vi Contents
3.2 Field radiated from an antenna 52
3.2.1 Elementary dipoles 52
3.2.2 Plane-aperture radiation 55
3.3 Directivity, gain, radiation pattern 59
3.3.1 Radiated power 59
3.3.2 Directivity 60
3.3.3 Gain 60
3.3.4 Radiation pattern 62
3.3.5 Input impedance 63
Further reading 65
Exercises 66
4 Receiving antennas 70
4.1 Antenna reciprocity theorem 70
4.1.1 Reciprocity theorem applied to a source-free closed surface 70
4.1.2 Relation between the field on transmit and the field on receive 74
4.2 Antenna effective receiving area 75
4.2.1 Definition 75
4.2.2 Relationship between gain and effective receiving area 76
4.3 Energy transmission between two antennas 77
4.3.1 The Friis transmission formula 77
4.3.2 Radar equation 78
4.4 Antenna behaviour in the presence of noise 79
4.4.1 Power radiated by a body at absolute temperature T 79
4.4.2 Noise temperature of the antenna 82
4.4.3 Noise temperature of the receiving system 83
Further reading 84
Exercises 85
5 Antennas of simple geometry 87
5.1 Aperture antennas 87
5.1.1 Parabolic antennas 87
5.1.2 Rectangular horns 92
5.2 Wire antennas 101
5.2.1 Electric dipoles 101
5.2.2 Travelling wave rectilinear antennas 107
5.2.3 Loops and helical antennas 109
Further reading 113
Exercises 114
6 Printed antennas 117
6.1 Introduction 117
6.2 Different types of printed radiating elements 118
6.3 Field analysis methods 121
Contents vii
6.3.1 Methods of analysis of printed antennas 122
6.3.2 The cavity method 122
6.3.3 Application to a rectangular patch 125
6.3.4 Application to a circular patch 128
6.4 Input impedance, bandwidth and radiation pattern 130
6.4.1 Input impedance 130
6.4.2 Bandwidth 131
6.4.3 Radiation pattern 134
6.4.4 Polarization 134
Further reading 137
Exercises 138
7 Large antennas and microwave antennas 140
7.1 Introduction 140
7.2 Structures and applications 142
7.2.1 Structures 142
7.2.2 External characteristics required in applications 145
7.3 Fundamental propagation laws 152
7.3.1 Wavefronts 152
7.3.2 The Huygens-Fresnel principle of wave propagation 153
7.3.3 Stationary phase principle 154
7.3.4 Geometrical optics ray theory 157
7.3.5 Ray theory in quasi-homogeneous media 162
7.4 Antennas as radiating apertures 170
7.4 1 Antenna radiation and equivalent aperture method 170
7.4.2 Examples of microwave antennas and equivalent apertures 171
7.4.3 Far field radiation from an aperture 174
7.4.4 Examples of radiating apertures 179
7.4.5 Polarization of the radiated field: case where the field in
the aperture has the characteristic of a plane wave 186
7.4.6 Geometrical properties of the Huygens coordinates 191
7.4.7 Aperture radiation in the near field 193
7.4.8 Gain factor of a radiating aperture 196
Appendix 7A Deduction of the Huygens-Fresnel principle from
the Kirchhoff integral 200
Further reading 201
Exercises 202
8 Primary feeds 207
8.1 General properties 207
8.1.1 Introduction 207
8.1.2 General characteristics of primary feeds 208
8.1.3 Radiation from radially-symmetric structures 215
8.1.4 Primary aperture in an incident field 221
viii Contents
8.2 Horns 223
8.2.1 General properties 223
8.2.2 Small flare angle horns and open-ended guides 224
8.2.3 Flared horns 225
8.2.4 Multimode horns 226
8.3 Hybrid modes and corrugated horns 229
8.3.1 Circular aperture radiating a pure polarization 229
8.3.2 Search for hybrid mode waves 229
8.3.3 Radiation pattern 235
Further reading 240
Exercises 241
9 Axially symmetric systems 244
9.1 Introduction 244
9.2 Symmetry properties -propagation of polarization, radiation
patterns 245
9.3 Principal surface 247
9.3.1 Definition 247
9.3.2 Pupil- aperture angle -focal length 248
9.3.3 Equivalent aperture of the system 249
9.4 Transfer function 250
9.5 System gain 252
9.5.1 General expression 252
9.5.2 Expression obtained from the primary gain g' and the
transfer function 253
9.5.3 Effect of various factors in the gain function 253
9.5.4 Concept of optimal primary directivity 255
9.6 Radiation patterns 258
9.6.1 Equivalent aperture illumination 258
9.6.2 Axisymmetric primary pattern with pure polarization 258
9.6.3 Effect of blockage 260
9.7 Aberrations in axially-symmetric systems 262
9.7.1 Introduction 262
9.7.2 Main aberrations in the defocusing plane 262
9.8 Axially symmetric systems considered in reception 267
9.8.1 Effect of transferfunction 267
9.8.2 Diffraction in the vicinity of the focus F of an element
dS' of a spherical wave S' 269
9.8.3 Analysis of a diffraction pattern -contribution of an
elementary crown of the spherical wave -hybrid waves 270
9.8.4 Axial field 271
9.8.5 Transverse distribution of the diffracted field in the
focal plane 272
9.8.6 Axially-symmetric systems with a small aperture 9 273
0
Contents ix
9.8.7 Constant transfer function 275
9.8.8 Non-constant transfer function 277
9.8.9 General case: system with a very large aperture 278
9.9 System considered in reception: transfer of the energy contained
in the diffraction pattern to the primary aperture 279
9.9.1 Diffraction pattern produced around the focus by an
incident non-axial plane wave 279
9.9.2 Radiation pattern of the system associated with a
given primary aperture 281
9.9.3 Examples of applications 282
9.9.4 Axial gain of an axially-symmetric system -effect of
the diameter of the primary aperture 283
9.10 Radiation in the Fresnel zone of a Gaussian illumination
-application to the transport of energy by radiation (Gobeau's waves) 286
Further reading 288
Exercises 289
10 Focused systems 297
10.1 Introduction 297
10.2 The Cassegrain antenna 298
10.2.1 Introduction 298
10.2.2 Geometry 299
10.2.3 Equivalent primary feed 301
10.2.4 Principal surface 302
10.2.5 Cassegrain with shaped reflectors 303
10.2.6 Diffraction pattern of the subreflector 306
10.2.7 Blockage by the subreflector 312
10.2.8 Schwartzschild aplanetic reflector 316
10.3 Tracking systems 317
10.3.1 Introduction 317
10.3.2 General characteristics of radar echoes 319
10.3.3 Conical scanning 324
10.3.4 'Monopulse' antennas 332
10.3.5 Beacon tracking 349
10.4 Non axially-symmetric systems 349
10.4.1 Offset reflector 349
10.4.2 Shaped reflectors -pattern synthesis 353
Further reading 360
Exercises 361
11 Arrays 363
11.1 Introduction 363
11.1.1 Phased arrays 364
11.1.2 Bandwidth -use of delay lines -subarrays 364