Microwave Antenna Theory and Design

636 Pages·027.52 MB·English

by  Samuel Silver

MICROWAVE ANTENNA
THEORY AND DESIGN
Ediied by
SAMUEL SILVER
ASSOCIATE PROFESSOR OF ELECTRICAL ENGINEERING
UNNEB.SITY OF CALIFORNIA, i3EP.KELEY
OFFICE OF SCIENTIFIC RESEARCH AND DEVELOPMENT
NATIONAL DEFENSE RESEARCH COMMITTEE
FIRST EDITION
NEW YORK, TORONTO LONDON
McGRAW-HILL BOOK CO,MPANY, INC.
1949
.,
,.,
MICROWAVE .$xTEN\-.$ THEC!R Y .ISD DESIGN
(hPYRIGH,T, 1949, B>- THE
hlC~RA W-HILL BOOK~(IIIP.I.NY, lKC.
P31XTEI) lx THE U>-lTEI) STATES OF AMERICA
.111rights Testwed. This book, or
parts thereof, HI(IY not bereproduced
in any form (rilho?(lprr)rlission of
/he ,L)(///i)shers,
THE MAPLE PRESS COMPANY, YORK, PA,
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lf[CRO JV.4VE ANTE.VNA TfZEOR Y AND DESIGN
EDITORIAL STAFF
SAMUEL SILVER
HUBERT M. JAMES
CO.VTRIB L’TI.VG APTHORS
J. E. llATON R. hf. RIZDHEFFER
L. J. I;YGES J. R. RISSER
T. J. KEARY S. SILVER
H. KRUTTER O. A. TYSON
(2. G. hlAcFARL.4NE L. C. \’AN ATTA
Foreword
THE tremendous research and development effort that ~ventinto the
development of radar and related techniques during }Vorld IJ ar II
resulted not only in hundreds of radar sets for military (and some for
possible peacetime) use but also in a great body of information and ncm
techniques in the electronics and high-frequency fields. 13ecause this
basic material may be of great value to science and engineering, it seemed
most important to publish it as soon as security permitted.
The Radiation Laboratory of 311T, ~vhichoperated under the super-
vision of the National Defense Research (’ommittec, undertook the great
task of preparing these volumes. The ~vorl{described berein, ho\\-eyer,is
the collective result of ~vork done at many laboratories, Army, Xavy,
university, and industrial, both in this country and in JZngland, (<anada,
and other Dominions.
The Radiation Laboratory, once its proposals ]vere approved and
finances provided by the Office of Scientific Research and l)evelopment,
chose Louis N. Ridenour as Fklitor-in-(’bief to led and direct tbe entire
-,
project. An editorial staff ]vas then selected of those best quulificd for
this type oftask. Finally the authors for the various volumes orchapters
or sections were chosen from among those experts ~vho~t-ereintimately
familiar with the various fields, and ]vbo \vereable and willing to ]vrite
the summaries of them. This entire staff agreed to remain at ~vorkat
MIT for six months or more after the \\-orkof the Radiation I.aboratory
was complete. These volumes stand as a monument to this group.
These volumes serve as a memorial to tbe unnamed hundreds and
thousands of other scientists, engineers, and others ]vho actually carried
on the research, development, and engineering work tbe results of which
are herein described. There ~vereso many involved in this ~vorkand they
worked so closely together even though often in \\-idelyseparated labora-
tories that it isimpossible to name or even to know those ]vho contributed
to aparticular idea ordevelopment, (My certain ones ~vho~u-otereports
w-or articles have even been mentioned, But to all those ~vhocontributed
~ in any way to this great cooperative development enterprise, both in this
~ country and in England, these volumes are dedicated,
a
L. A. DLTBRIDGE.
z 1,!
Preface
THE need that arose during the ]var for utilizing the microwave region
of the radio frequency spectrum for communications and radar stimu-
lated the development of nelv types of antennas. ‘l’he problems and
design techniques, lying as they do in the domain of both applied electro-
magnetic theory and optics, are quite distinct from those of long-wave
antennas. It is the aim of the present volume to make available to the
antenna engineer a systematic treatment of the basic principles and the
fundamental microwave antenna types and techniques. The elements
of electromagnetic theory and physical optics that are needed as a basis
for design techniques are developed quite fully. Critical attention is
paid to the assumptions and approximations that are commonly made
in the theoretical developments to emphasize the domain of applicability
of the results. The subject of geometrical optics has been treated only
to the extent necessary to formulate its basic principles and to sho~vits
relation as a short wavelength approximation to the more exact methods
of field theory. The brevity of treatment should not be taken as an
index of the relative importance of geometrical optics to that of electro-
magnetic theory and physical optics. It is in fact true that the former
is generally the starting point in the design of the optical elements
(reflectors and lenses) of an antenna. However, the use of ray theory
for microwave systems presents no new problems over those encountered
in optics—on which there are a number of excellent treatises—except
that perhaps the law of the optical path appears more prominently in
micro~vave applications.
In the original planning of the book it was the intention of the editors
to integrate all of the major wQrk done in this country and in Great
Britoin and Canada. This proved, however, to be too ambitious an
undertaking. Nfany subjects have regrettably been omitted completely,
and others have had to be treated in a purely cursory manner. It \vas
unfortunately necessary to omit two chapters on rapid scanning antennas
prepared by Dr. C. V. Robinson. The time required to revise the
material to conform ~viththe requirements of military security and yet
to represent an adequate exposition of the subject would have unduly
delayed the publication of the hook. Certain sections of Dr. Robinson’s
material have been incorporated into Chaps. 6 and 12.
ix
x PREFACE
I take pleasure in expressing here my appreciation to Prof. Hubei-t
M. James who, as Technical Editor, shared with me much of the
editorial work and the attendant responsibilities. The scope of the book,
the order ofpresentation of the material, and the sectional division within
chapters were arrived at by us jointly in consultation with the authors.
I am personally indebted to Professor .James for his editorial Ivork on
my own chapters.
The responsibility for the final form of the book, the errors of omission
and commission, is mine. A word of explanation to the authors of the
various chapters is in order. After the close of the Office of I’ublications
and the dispersal of the group, I have on occasions made use of my
editorial prerogative to revise their presentations. I hope that the results
meet ~viththeir approval. The policy of assignment of credit also needs
explanation. The interpretation of both Professor James and myself of
the policy on credit assignment formulated by the Editorial Board for
the Technical Series has been to the effect that no piece ofwork discussed
in the text would be associated with an individual or individuals. Radi-
ation Laboratory reports are referred to in the sense that they represent
source material for the chapter rather than individual acknowledgements.
References to unpublished material of the Radiation Laboratory note-
books have been assiduously a~oided, although such material has been
drammupon extensively by all of us. In defense of this policy it may be
stated that the ]vorlcat the Radiation Laboratory was truly a cooperative
effort, and in only a few instances would it have been possible to assign
individual credit unequivocally.
The completion of the book was made possible through the efforis of
a number of people; in behalf of the editorial staff and the authors I wish
to acknowledge their assistance and contributions. Mrs. Barbara Vogel
and Mrs. Ellen Fine of the Radiation Laboratory served as technical
assistants; the production of figures and photographs \vasexpedited by
hlrs. Frances Bourget and Mrs. nary Sheats. It proved impossible to
finish the ]t-orl<by the closing date of the Office of l’ublications; the h’aval
Research Laboratory accepted the ~vork as one of the projects of the
newly formed Antenna Research Section and contributed generously in
personnel and facilities. Special thanks are due to A. S. Dunbar,
1, Katz, and Dr. I. Maddaus for their editorial assistance; to Queenie
Parigian and Louise Beltramini for preparation of the manuscript;
and to Betty Hodgkins who prepared almost all of the figures.
The editors are indebted to Dr. G. G. Macfarlane of the Tele-
communications Research Establishment, Great Britainj for his
critical review of several of the theoretical chapters and his contribution
on the theory of slot radiators in Chap. 9. John Powell of the
Radiation Laboratory prepared material on lenses that was used in
Ch:lp. 11. The S:1( iomd Rcsc:wch (’ouncil of Can:&~ :md the llrit isll
(’entnd Radio 13urw~uh~~vc~rwiously granted us permission to ti~li(.
m:ltcrial from (‘unudi:m :md I;ritish reports in accord:mcc ~~ithmlrrrnt
security U3glllotioms. ‘l>hc I?wII Telephone I.abora,twy supplied the
photographs of mct:d lens antennas.
S.4MUEL khLVlil{.
K:\v\T, lll)sl’.\1i1lI T.WIMWIIY,
‘!f”lslllxlm)x, l). (’.,
:lprd, 1947.
.
Contents
FOREWORD BYL. A.DUBRmGE . . . . . . . . . . . . . . . . . . vii
PRE1744.C.E. . . . . . . . . . . . . . . . . . . . . . . . . . . ix
CHAP.1. SURVEY OF MICROWAVE ANT~~NNADESIGN PROBLEMS 1
1.1. The WavelcngthRegion. . . . . . 1
1.2. .Lntenna Patterns . . . . . . . . . . . . . . . . . . . ..2
1.3. Types of }Iicrowave Beams. 6
1.4. lIicrowave Transmission I,ines . 7
1.5. Radiating llernents . . . . . . . . . ..8
16. .4 Survey of kllcrowavc }.ntenna Types 9
1.7. Impedance Specifications. 13
1.8. Program of the Present Volume 14
CH.4P.2. CIRCUIT RJ31JATIOIW, Rf3CIPR0CiTY THW3RF~!>fS. 16
21. Introduction . . . . . . . . . . . . . . . . . . . ...16
22. The Four-terminal ~etwork. 17
23. The Rayleigh Reciprocity Theorcnl 19
2.4. Th6venin’s Theorem and the Nfzximum-power Theorem 20
2.5. The Two-wire Transmission I,ine 21
2.6. The Homogeneous Transmission I,ine 23
2.7. The LosslessLin e..... ..26
2.8. Transformation Charts. 29
2.9. The Four-terminal N“etwork l’:quivalent of a Sectio]l of Trans-
missiOn Line.... . . . . . 36
TRANSMI~EVG ANn RECEIVING ANTENNAS. . 37
2.10. The Antema as a Terminating Impedance 37
2.11. The Receiving Antenna System 40
2.12. The Transmitter and Receiver as a Coupled System 45
2.13. Reciprocity between the Transmitting and Itecei\,ing Patterns of
an Antenna . . . . . . . . . . . . . . . . . . . ...48
2.14. The .kverage Cross Section for a Matched System 50
2.15. Dependence of the Cross Section on Antenna Mismatch 51
2.16. The Four-terminal Network Representation. 53
2.17. l)evelopment of the N’etwork Equations 56
2.18. The Reciprocity Relation between the Transfer Impedance
Coetlicient s, . . . . . . . . . . . . . . . . . . ...59
X111
xiv CO.YYfil.VTS
CHAP. 3. R.\III.iTIOS FR031 CUIUWXT I)ISTRII)I”T1OSS. (iI
31. Tllc Field Ilquations. 6]
32. The (;onstit,ltive Paramctrrs; I.inc:wity mid SIlperpo sition . 6,5
33. Ilou])dary Contlitions. 66
3~. The Field ~q~latio]ls for H:mnonic TIInc ])(,p[,lld(>I1[W 68
3.5. I’aynting’s Thmreln . . . . M)
36. The ll-a\,c k;qll:ltions. 71
3.7. Simple l~avc Sollltions. 73
38. General Sollttion of the Field I}q,,~tiol,s in Tcr],,s of tl)r fk),,rtcs,
for a Ti]llc-pcriodir lri(ld. 8(I
3.9, Field ]),,e to Sollrtt,s in an U]IhoIuI(ltYi Ii(,gion 84
3.10. Field in a licgion Rotmdcd hy S(lrfa((,s of I]lfillltcl}- (’OI)(l\l(tIvr
llc,clia . . . . . . . . . . . . . . . . . . . . . ..8fi
311. Tl](, Far-zone Fields 87
312. I’olarization. !)1
3~13. The I;lcctric l)ipolc !)2
314. Tllc IItignetir lh]mlc 95
3.15. The F:lr-zonr Firl(ls of I,i]l(,-rurr(,nt l)istrilllltif!)ls !)(i
316. The “H:df-~1 IV(, l)ilmlt, ” !)8
317. Sllpcrpm]tion of l~icl{ls !)!1
31S The 1)0111>1(,-(111)01S(ystem 101
319. I{cgldur Space .Irr:iys 104
C][.IP. 4. ll-.l’;l; FI{O>-TS :~~1) RAYS 107
41. TIICII\lygrns-Crccn Forn~lll:Lfor thr Ill((,tr(l]]]:Lg]l(ti[, l’itl(l 107
42, Gcol]lctrical ()~]tirs: l~”avefronts and l{:lys 110
43. C1lr~:itllrr of the Ilmys in an Inllo]]Iogc,l](,[~!ls Ilcdiunl 111
4+. Energy FlOIvin (lcometrical Optics 112
45. (;comctrical optics :is :LZero-~ra~clcngth I,in]it 114
46. The H~lygens-Frrsnrl Principle and Gconlctriral Optics: The Far-
zonc .kpproximation 116
47. The Principle of Stationm-y I’hasc 11{)
48. Ft=rnlat’s I’rincip]e. 122
4.9, The I,a,v of the optiral Path 125
(’]~\l,, 5, S(’.LTTERISC, .kN-T) DIFFR.ACTIOX. 12!)
51. (;cncral (’onsidcrntions 129
52. Bol]ndary (’o]lditions 130
53. Iieflection hy an Infillite Plane S(lrt’arc; the l’rinril)lv of ItII:igrs 132
APPROXIMATE JIETHODS FORREFLECTOI+SOF ;lILBITMARYS]J.\PE ,.. 137
54, The Geometrical-optics IIcthorl 138
55, Calculation of the Scattrrrd Firl[l 139
56, Superposition of the So~lrcc l~icl(l :IIIdtl)(, Sc:\ttercd l~icld. 143
57, The Current-distril, ~ltion 31cthod 144
58. Calc(llation of the Scattrrrd Field 146
59. Application to Point-source md IJirl{J-sollrre l;ecds. 149
510. Reaction of a Reflector on a Point-source Feed 155
511. The .Aperture-fielci Ifethod . . 158
512. The Fraunhofer Region. ,.. 160
.
co’YTA”7’ls’ xv
l)IF1.ll.\(1r0.N... . . . ...,,162
S.IS, (i,r,crtLI (’~)])si,l,,r:,iit)])s mI tht, .ipproxim:ltc Ilt,tllods 162
514. l{ttlll~,tltJJlto :1S[alilr l)illr:~(tlf)n I’I’o I)lcIN 164
515. l)~~lli]lct’s l’rl]l{ipl~i for tll(’ l<;lc,~tro]ll:tg])f,ti(, Ir](,ld 167
(’ti~l,. 6. .lI’KI{TURF; ll.LL’llll-ATIOX” AX]) .l>-TI,;X-XA I’ATTERNS 169
61. l’ril]l:~ry and S[,co]ltlxry l’tlttrms 169
62. Tll(, l)iffr:trtion Fieltl 169
(i3. I’ouri(r Integral li(,l)rc,s(,]ltati{jl~ of the Fraunhofcr lie~ion 174
64, (+CJI(M1I:caturts of tht, Sccolld:wy l’~ttvm 175
6,5. TIICl{rctmlg~ll:~r .fporture ]80
6.ti. Tl!o-(lilllt,nsio]lal Prol)lcms 182
67. I’l]:i.w-error kYfects. . 186
08. TIIC(’irc(llm .ipcrturc 192
&9. Th(, Field o]] the Axis in thr Frcsnrl ]tcgion ]96
(’l[,\],, 7. l[I(:ROIV,.fV}; TRAA-S~f ISSIOA” I,IN-ES 200
71 llicro~j :ivc nnd I,ong-~vave Trimsmission I,illm 200
72. l’rop:l~atio]l in ~f”:~vcgllidcs of l“niform (;ross Swtion 201
73. orthogo]lallty Rcl:ltions and Power Flow. 207
74. Transnlissiun I,inr (’onsidcrations in l~:lvrguidrs 209
75. XctJtork Kqllivalents of Junrtions and ohstaclcs 214
76. 7’/l.l/-modc Trallsmission I,irlcs 216
77. (’ozxis,l I,incs: ?’~.!f-rnodc 217
7.8. (’oaxial I.ines: T.If- and T]i-nlodcs 219
7.!), (’:Is,.acIc Tmnsformcrs: TJ~.lf-mode 221
71o. I’arallel St~lhs and Series ILeactancm. 223
711. licctang~llar }Vavcguidcs: I’A’- and ?’,lf-modes 226
712. Impcdanrc Transformers for Iiectangular (;uidcs 229
713. Circular ll-aveguide: T~- and TJf-modcw. 233
7.14. Ivindows for LTSCin Circular Guides 235
715. I’arallel-plate i~aveguide. . 235
716.11esignN Totes. . . . . . . . . . . . . .. 238
CHAF.8. lfICROWAVE DIPOLIl A3JTE~~AS ANI) F13f?DS 239
81. Characteristics of Antenna Feeds 239
8.2, Coaxial I,ine Terminations: The Skirt Dipole 240
83. Asymmetric Dipole Termination. 242
84. Symmetrically 13nergizcri Dipoles: Slot-fed Systems 245
85. Shape and Size of the Dipole . 248
86. lVaveguidc-line-fcd Dipoles. . 250
87. Directive Dipole Feeds, . . . 250
88. Dipole-disk Fords . . . . . . . . . . . . . . . . . . ...251
89, Double-dipole Feces, .,.... . . . . . . . . . . . . .253
8.10. Lfulti-dipole Systems, . . . 256
CHAP.9. LINI?AR ARRAY AXTEiYNAS AND FF23DS 257
9.1. (kmcral Considerations. . 257