beam shaping of sectoral electromagnetic horn antennas using corner reflector technique

171 Pages·2013·6.79 MB·English

BEAM SHAPING OF SECTORAL ELECTROMAGNETIC
HORN ANTENNAS USING CORNER REFLECTOR TECHNIQUE
K. T. MATHEW
A thesis submitted for the Degree of
DOCTOR OF PHILOSOPHY
To
THE UNIVERSITY OF COCHIN
MICROWAVE LABORATORY DEPARTMENT OF PHYSICS
UNIVERSITY or cocum cocnm
KERALA mum
1978
DECLARATION
Thia is to certify that this thaaia ie
an original authentic record of original
work carried out by Hr.K.T. Mathew, H.Sc.
under my euperviaion and guidance, in the
Department of Phyaice, University of Cochin,
Cochin 682 022 and that no part thereof haa
been presented by him for any other degree.
Hr.K.T.Mathew has paaead the H.Sc. Degree
Examination of the University of Kerala in
the First Class. Ha hae also paeead the
Ph.D. Qualifying Examination of the Cochin
University in February 1977.
Cochin - 22 ' I, _
10 Hey 197a
Supervising Teacher
Dr.K.Gopalakriehnan Nair
Reader in Induetrial Phyeice
Cochin Univeraity.
ACKNOHLEDGEHENT§
It is with great pleasure I express my sincere
gratitude to Dr.K.Gopalakrishnan Nair, Reader in Industrial
Physics, for his able guidance and competent advice through
out my research work. His considerate and inspiring atti­
tude encouraged me much for completing this work in time.
I am extremely grateful to Prof.K.5athyanandan
and Prof. Joy George for providing Laboratory and Library
facilities.
All the members of the faculty and technical per
eonnel in the Department of Physics were very cooperative
and helpful and I wish to place on record my sincere grati­
tude to all of them.
I acknowledge with pleasure the cooperation and
encouragement I received from the Principal, Prof.(Sr.)
Marita and my colleagues of 5t.Tereaa's College, Ernakulam.
I em sincerely thankful to all my friends in
particular Mr.G.Mohanachandran, Mr.E.J.Zachariah and
Mr.K. Vasudevan for their cooperative attitude.
Hy thanks are also due to Hr. H.S. Hukundan
for carefully typewriting the manuscript.
K.T. MATHEW
CONTENTS
Page
List of Symbole 5
List of Figures I
Liet of Tablee
10
Chapter I - Introduction
12
II - Feet work in the field
Chapter 24
Chapter III - Methodology, Experimental
Techniquee end Heeauramenta 36
- Experimental Reeulta .­
Chapter IV 58
A)- Reeulte Obtained with n¢z¢111=
Flanges on Sectoral Electromagnetic
Horn Antennae .. .­
59
B)­ Reeulte Obtained with Corner
RQf1BCtUr System ac ae
Bl
Chapter V - Coeparetive Analyeia of the
Experimental Reeulte .­
103
Chapter VI - Theoretical Coneideretiene 116
Chapter VII - Conclueione 145
CO
150
Appendix A1
159
Appendix A2
References 166
LIST UF SYMBOLS
Axial length of a horn
Flare angle of a horn
Difference of Path length for a wave
reaching the aide of the horn
Traneverse Electric
Transverse Magnetic
The free epace wavelength of radiation
Aperture of the horn in the E-plane
erpraeeed in free space wavelength
Aperture of the horn in the H-plane
expressed in free space wavelength
Bearing angle of the antenna or the
angular displacement of the distant point
where power or intensity is naseured.
x
Included angle of the flange or corner
reflector elements.
Distance of the point in the far field.
AE sin 9
Power or equara of amplitude of the field
at a dietant point corresponding to the
bearing angle 9 .
On-axis power.
Any integer including zero.
..- 5-­
Net phaee change of the field at a point
I1
due to the aecondary eource relative to
the primary.
Phaee difference of radiation from the
Z
eecondary due to the difference in path
affected at a point H.
Width of flange or corner reflector element.
H
width of individual elenente when not equal.
v1, v2
Dietence of flange from the aperture of horn
Z
neaeured along horn axie.
2°, 2' Optieua and Hinieua valuea of Z giving naxieue
and minimua valuee of Po respectively.
A Angle between the horn axie and flange axie.
Longer aperture dimeneion of the trans­
D1’ D2
mitting and receiving antennae.
Gain of an antenna.
G
VSHR Voltage Standing Have Ratio.
Half Power Bean Width
HPBH
9 2%‘­
Anplitude of excitation of the eecondary
K
radiatore.
The reeultant amplitude of
R
°*°1t'*i°"*0f the eecondary rediatore.
--7-­
Dietance of feed dipole from the apex
of the corner reflector.
Conplex quantity J -1
Beeeel function of the order indicated
by the suffix end erguement ehoun in
brackets.
LIST OF FIGURES
51.N0 .1 Fi.g1url No. Page 0.
2 1.2
3 1.3
4 3.1
5 3.2
6 3.3
7 3.4 Plato
Plat:
B 3.5
9 3.6 Plato
Plate
3.7 Plato
10
12 3.9
3.0 Plate
11
14 4.1
4.1 1
13 A)
15 4.2
(B) Plato
16 4.3
4.4
17
4.5
18
4.6
219 1 4.8
4.7
20
22 4.9
23 4.10
24 4.11
S.No. Figaro No. Pogo No
4.12 94
4.13 97
4.14 99
4.15 100
4.16
101
5.1(A) 104
5.118) 105
5.2(A) 107
5.215) 108
5.3 110
5.4
111
5.5 113
6.1 118
6.2 122
6.3 129
6.4 131
6.5 134
6.6(A1 140
6.s(n> 141
152
A1.1
153
A‘.2
156
A103
A2o1(A) Plfiti 161
162
A2.1(B)
164
AZQZ
_-9_­
LIST OF TABLES
S.No. Tabla No. Page 0.
1 3.1
2 4.1
44
3 4.2
62
4 4.3
63
5 4.4
64
6 4.5
7 4.6 T1
74
B 4.7
77
9 4.8
TB
1U 4.9
82
11 4.10
86
12 4.11
87
13 4.12(a) 91
92
14 4.12(b)
15 4.12(c) 93
16 6.1
96
17 6.2
128
1B 6.3
138
19 A‘.1 142
20 A1.2 154
157