The Ohio State University. ,f. #,. AIRBORNE ANTENNA ... Columbus, Ohio. 43212. Report No. 716199-4 ...... DO 5622 NRD:I,NRDX. I. [ READ: MPIRD(NRD),.
,f
#,
The Ohio State University
AIRBORNE
ANTENNA RADIATION CODE USER'S MANUAL
PATTERN
Walter D. Burnside Jacob J. Kim Brett Grandchamp Roberto G. Rojas PhiI ip Law
The Ohio
State University
ElectroScience Laboratory Department
of Electrical
Columbus,
Ohio
Engineering 43212
Report No. 716199-4 Contract No. NSG-1498 September 1985
National
Aeronautics and Space Administration Langley Research Center Hampton, VA 23665
(_ASA-CI_-181249) AIREGBNE tATTEBN CODE I]SER'S MAI_UAI. U_iv.) 261 p Avail: _IS
N87-27C96
AE_,E_A BADIATION (Cl_io State _C A12/MF A01 CSCL 20N G 3/32
Unclas 0093171
NOTICES
When Government drawings, specifications, or other data are used for any purpose other than in connection with a definitely related Government procurement operation, the United States Government thereby incurs no responsibility nor any obligation whatsoever, and the fact that the Government may have formulated, furnished, or in any way supplied the said drawings, specifications, or other data, is not to be regarded by implication or otherwise as in any manner licensing the holder or any other person or corporation, or conveying any rights or permission to manufacture, use, or sell any patented invention that may in any way be related thereto.
50272
-101
REPORT
I z. J
DOCUMENTATION
PAGE 4.
Title
and
REPORT
NO.
i
3
2.
Subtitle
AIRBORNE ANTENNA RADIATION
PATTERN CODE USER'S MANUAL
3'.
Recip,ent's
S.
Report
Accession
No.
Date
____September 1985 6.
7"
Author(s) 8.
W.D. 9.
Burnside,
Perfo_ing
J.
O_enizetion
Nsme
Kim, and
B.
Grandchamp,
R.
Rojas,
P.
S_nsoring
Organization
Name
and
Address
....
15.
Supplemsnta_
16.
Abstract
Rapt.
NO.
10.
Project/Task/Work
1].
Contract(C)
Unit_N0.
or
Grant(G)
"........
No
(c) NAG-1498 (G)
Address
National Aeronautics and Space Langley Research Center Hampton, VA 23665
Orl[anization
716199-4
The Ohio State University ElectroScience Laboratory 1320 Kinnear Road Columbus, Ohio 43212 ]2.
Performing
Law
13.
Type
of
Report
&
Period
Covered
Administration -
I
ii: .......................... ......
Notes
(Limit:
200
words)
This report describes the use of a newly developed computer code to analyze the radiation patterns of antennas mounted on a composite ellipsoid and in the presence of a set of finite flat plates. Furthermore, it is shown how the code allows the user to simulate a wide variety of complex electromagnetic radiation problems using the ellipsoid/plates model. The code has the capability of calculating radiation patterns around an arbitrary conical cut specified by the user. The organization of the code, definition of input and output data, and numerous practical examples are also presented. The analysis is based on the Uniform Geometrical Theory of Diffraction (UTD), and most of the computed patterns are compared with experimental results to show the accuracy of this solution.
:iECEDING
117.
Document
Analysis
a.
pAGE BLANK
NOT
FILMED
Descriptors
KEY WORDS :
111
b.
Identifiers/Open-Ended
c.
COSATI
Terms
Uniform Geometrical Theory of Diffraction Ray optical technique Electromagnetic radiation and scattering Airborne antenna radiation pattern Computer code user's manual High frequency analysis Composite ellipsoid Experimental verification
(UTD)
Field/Group
Availability
Statement
...................
[ 1. s.our,,.Cla.; _.,.R'Po.) Unclassified
(Sea
ANSI--Z39.I
8)
Sea
Instrucfionl
ii
on
/2o.
Security
J
Unclassified
Reverse
Class
(This
Page)
OPTIONAL
FORM
(Formerly
NTIS-35)
Department
of
272
CommerCe
(4-77)
TABLE
OF CONTENTS
Page
LIST
NF TABLES
LIST
OF FIGURES
V
vi
I.
INTRODUCTION
1
II.
PRINCIPLES
OF OPERATION
5
III.
DEFINITION
OF INPUT DATA
11
COMMAND PART A.
B.
C.
D.
18 and Frequency
A1.
COMMANDUN
of_
A2.
COMMAND FO
21
Fuselage
Geometry
Commands
2(I
Unit
Related
Commands
22
BI.
COMMAND
FG
22
B2.
COMMAND
FB
24
B3.
COMMAND
FC
26
Source
Geometry
Related
Commands
27
CIo
COMMAND SG
27
C2.
COMMAND SP
32
C3.
COMMAND LS
33
Plate
Geometry
Related
Commands
38
DI.
COMMAND PG
38
D2.
COMMAND PI
41
iii
Page
E.
F.
G.
Pattern
Cut
Related
Commands
42
El.
COMMANDPD
42
E2.
COMMANDRT
46
Specific
Terms
Related
Commands
4g
FI.
COMMANDTO
4g
F2.
COMMANDRD
53
F3.
COMMANDDD
54
F4.
COMMANDRS
55
Execute
and Output
Related
Commands
56
GI.
COMMANDLP
56
G2.
COMMANDPP
56
G3.
COMMANDBO
5R
G4.
COMMANDEX
58
IV.
INTERPRETATION
V.
PROGRAMOUTPUT
VI.
APPLICATION
OF INPUT DATA
59 68
OF CODE TO SEVERAL SIMPLE EXAMPLES
74
{
VII.
APPLICATION
OF CODE TO AIRCRAFT
REFERENCES
SIMULATIONS
89 246
iv
LIST
OF TABLES
Table I II
Page BLOCK DIAGRAM OF THE MAIN PROGRAM BLOCK DIAGRAM OF THE INPI_IT DATA ORGANIZATION COMPUTER CODE
v
R F_R THE
12
LIST OF FIGURES
Page
Figure Definition 2
of fuselage
23
geometry.
Definition of antenna phase reference point for computer code. Note that PHS = @s and ZS = - IZsl in the above drawings.
29
Source geometry.
30
(Note that RHOA(MS)=p A and
PHIA(MS)=¢
Definition
of flat plate
Definition
of pattern
Definition geometry.
of rotate-translate
A) 39
geometry.
45
axis. coordinate
7(a)
Data format used to define another flat plate.
a flat plate
7(b)
Data format used to define
a box structure.
7(c)-(f)
Fuselage and wing geometries for aircraft model looking from the front. The antenna is assumed be on the top portion of the models. used to define
intersecting
64
64 65 to
Data format a fuselage.
8
Composite fuselage.
9(a)
Line printer
output
for the Eop fields
of Example
1.
7O
9(b)
Line printer
output
for the Ecp fields
of Example
1.
71
geometry
coordinate
to
the aircraft
10
Transformed cuts.
11
A monopole
12
Radiation pattern of monopole mounted on a composite ellipsoid at frequency .3 GHz. (a) (b) (c) source located at PHS=25 °, ZS=3_ (d) (e) source located at PHS=25 °, ZS=IO_ and fuselage chopped off at ZC2=14_ for (e).
mounted
sysems
simulating
attaching
66
7(g)
ellipsoid
a flat plate
47
system
for the conical
on a composite
vi
pattern
ellipsoid.
67
72
74 76
Page
Figure 13
A bend
14
Various
15
Roll
16
Total solution commands.
17
Edge to
edge
18
Edge to
surface
19
Test
plate
attached
to
a composite
77
ellipsoid.
78
GTD terms. plane
radiation (S+R+D)
plate
locations
84
pattern. after
using
"PI:"
88
and "PG:"
qo
attachment.
plate for
go
attachment.
the
antenna
installation
g4
on the
Boeing
737 aircraft.
2O
Boeing
737 aircraft.
21
Computer simulated model of a Boeing 737 aircraft. The antenna is located at Station 220.
96
22
Roll plane pattern Station 220 on top
97
23
Elevation plane pattern of a _/4 monopole mounted Station 220 on top of a Boeing 737 aircraft.
24
Azimuth Station
25
Azimuthal at Station
26
Elevation Station ai rcraft.
plane 250 (off
27
Elevation Station
plane pattern of a _/4 monopole 305 on top of a Boeing 737 aircraft.
28
Computer simulated model for at Station 222 on the bottom Boeing 737 aircraft.
29
Elevation Station
95
of of
a _/4 monopole mounted a Boeing 737 aircraft.
plane pattern 220 on top of
of a I/4 a Boeing
conical patterns 220 on top of pattern center)
monopole mounted 737 aircraft.
of a _/4 monopole a Boeing 737 aircraft.
at
mounted
a _/4 monopole of the fuselage
mounted
mounted of a
mounted at 737 aircraft.
g8
gq
at
of a >,/4 monopole mounted on top of a Boeing 737
plane patterns of an antenna 222 on the bottom of a Boeing
vii
at
I00
at
106
at
107
109
110
Page
Figure 30
114
Computer simulated model for a _/4 monopole mounted at Station 950 on the bottom of the fuselage of a Boeing 737 aircraft.
31
Elevation plane pattern of a _/4 monopole mounted at Station 950 on the bottom of a Boeing 737 aircraft.
115
32
KC-135 aircraft.
117
33
Computer simulated antenna is located
model of a KC-135 over the wings.
aircraft.
The
118
34
Computer simulated antenna is located
model of a KC-135 aircraft. forward of the wings.
The
119
35
Elevation plane pattern a KC-135 aircraft.
36
Elevation plane pattern for a circumferential KA-band waveguide mounted on a KC-135 aircraft.
122
37
Elevation plane pattern for an axial KA-band waveguide mounted on a KC-135 aircraft.
123
38
Roll plane pattern KC-135 aircraft.
39
Roll plane pattern for a KA-band circumferential waveguide mounted on a KC-135 aircraft.
125
40
Roll plane pattern for a KA-band mounted on a KC-135 aircraft.
126
41
Azimuth plane pattern KC-135 aircraft.
42
Azimuth plane pattern for a KA-band circumferential waveguide mounted on a KC-135 aircraft.
128
43
Azimuth plane pattern for a KA-band mounted on a KC-135 aircraft.
129
44
Computer simulated on a KC-135.
45
Elevation plane pattern on a KC-135 aircraft.
for a ),/4 monopole
for a _,/4 monopole
mounted
axial
viii
axial
for Lindberg
for Lindberg
on
on a
waveguide
for a },/4 monopole
model
mounted
mounted
on a
waveguide
antenna
antenna
mounted
mounted
121
124
127
131
133
Figure
Page
46
Roll plane pattern a KC-135 aircraft.
47
Azimuth plane pattern a KC-135 aircraft.
48
Azimuth mounted
49
Cessna
5O
Model
51
Roll
52 53
for Lindberg
for
antenna
Lindberg
mounted
antenna
on
137
antenna
13g
mounted
conical pattern (0D:45 °) for Lindbert on a KC-135 aircra_=t.
135
on
143
402B. for Cessna
plane
pattern
402B with engines for
and fuel tanks.
Cessna
402B model.
Beechcraft
Baron with Antenna
in forward
Beechcraft
Baron model with engine
144 145
location.
148 149
housings. Rarnn
i50
on
152
Roll conical pattern for the Beechcraft propeller at 0° (vertical).
Baron with
154
56(b)
Roll conical pattern propeller at 45 ° .
Baron
155
56(c)
Roll conical pattern for Beechcraft propeller at go° (horizontal).
56(d)
Roll conical pattern propeller at 135 ° .
57
Variation in the roll conical pattern for the Beechcraft Baron due to the rotation of the
_A
PAll rnnlrml nmffarn (A_:R_ °) far Rpprhrraft model ............. shown in_ ....... Figure 5_.....................
55
Beechcraft one side.
56(a)
Baron
model
with
rotating
propellers
for the Beechcraft
Baron
for the Beechcraft
with
with
Baron with
156
157
158
propellers. 160
58
Cessna
59
Cessna 150 model. Dashed computer simulation.
60
Elevation
150.
plane pattern
ix
lines
are not part of the
for a Cessna
150 aircraft.
161
162
Page
Figure
167
61
F-16 fighter
62
Computer simulated
aircraft.
168
63
Azimuthal conlcal pattern (Op=lO °) of a },/4monopole mounted on top of a F-16 fighter alrcraft.
169
64
Azimuthal conical pattern (Op=20 °) of a },/4 monopole mounted on top of a F-16 fighter alrcraft.
170
65
Azimuthal conical pattern (oo=30 °) of a },/4 monopole mounted on top of a F-16 fighter alrcraft.
171
66
Azimuthal conical pattern (op=400) of a _,/4 monopole mounted on top of a F-16 fighter alrcraft.
172
67
Azimuthal conical pattern (0p=45 °) of a },/4monopole mounted on top of a F-16 fighter aircraft.
173
68
Azimuthal con cal pattern (OD=50 °) of a },/4 monopole mounted on top of a F-16 fighter alrcraft.
174
69
Azimuthal
conlcal
175
conlcal
176
conlcal
pattern (oD=65 ° ) of a _/4 monopole on top of a F-16 fighter al rcraft.
177
72
Azimuthal conlcal pattern (Op=70 °) of a _,/4 monopole mounted on top of a F-16 fighter alrcraft.
178
73
Azimuthal
pattern (0D=75 °) of a ),/4 monopole on top of a F-16 fighter al rcraft.
179
74
Azimuthal conical pattern (op=80 °) of a },/4 monopole mounted on top of a F-16 fighter alrcraft.
180
75
Azimuthal conical pattern (op=85:) of a },/4 monopole mounted on top of a F-16 fighter alrcraft.
181
76
Azimuthal conical pattern (OD=90 °) of a },/4 monopole mounted on top of a F-16 fighter alrcraft.
182
77
Azimuthal conical pattern (oD=95 °) of a _/4 monopole mounted on top of a F-16 fighter aircraft.
183
mounted 70
71
mounted
of a F-16 fighter
pattern (ep=60 °) of a },/4 monopole on top of a F-16 fighter al rcraft.
Azimuthal mounted
model
pattern (ep=55 °) of a },/4 monopole on top of a F-16 fighter al rcraft.
Azimuthal mounted
aircraft.
conlcal
X
Figure
Page
78
Azimuthal conical mounted on top of
pattern a F-16
(Op=lO0 °) of a L/4 fighter aircraft
monopole
184
79
Azimuthal conical mounted on top of
pattern a F-16
(_)o=I05°) of a _/4 fighter aircraft.
monopole
185
8O
Azimuthal conical mounted on top of
pattern a F-16
(0o=II0 fighter
°) of a _/4 aircraft
monopole
186
81
Azimuthal conical mounted on top of
pattern a F-16
(Op=l15 °) of a _/4 fighter aircraft.
monopole
187
82
Azimuthal conical mounted on top of
pattern a F-16
(op=120 °) of a _/4 fighter aircraft.
monopole
188
83
Elevation plane pattern top of a F-16 fighter,
84
Roll UI
plane Q
I
--.I.
pattern
IJ
I
I_llb_l
of
of CIII
a _/4
monopole
a _/4 monopole I_l
CII
mounted
F-4
86
Computer aircraft.
87
Azimuthal conical pattern (ep=105 °) mounted on the belly of a F-4 fighter
88
A-IO
89
Computer
90
Azimuthal conical pattern (op:105 °) of mounted on the belly of a A-IO aircraft.
91
C-141
92
Computer
93
Azimuthal conical on a C-141 aircraft.
94
Elevation plane pattern top of a C-141 aircraft.
g5
Missile model ram jets.
fighter
simulated
on
on top
189
190
b.
85
(Phantom)
mounted
aircraft. model
193
of a F-4
Phantom
of
194
fighter
a _/4 aircraft.
monopole
aircraft.
lg5
lO8
simulated
model
of an A-IO
199
aircraft. four
monopoles
aircraft.
200
202
simulated
for
model
of a C-141
patterns
of
a _/4
of a _/4
an axial
xi
slot
2O3
aircraft. monopole
monopole
mounted
mounted
mounted
between
on
two
2O5
210
213
Figure
Page
96
Roll plane pattern two ram jets.
97
Elevation plane pattern between two ram jets.
98
Missile
for an axial
slot mounted
for an axial
model for an axial
between
215
slot mounted
slot mounted
214
on a ram
217
jet. 99
Roll plane pattern jet.
for an axial
slot mounted
on a ram
218
IO0
Elevation plane pattern a ram jet.
101
S-band
on the Space
Shuttle.
224
102
Computer simulated model for a crossed-slot mounted on top of a Space Shuttle Orbiter.
antenna
225
103
Elevation plane patterns for a crossed-slot mounted on top of a Space Shuttle Orbiter.
antenna
226
104
Azimuth mounted
105
Roll plane radiation patterns for a crossed-slot antenna mounted on top of a Space Shuttle Orbiter.
228
106
Roll conical patterns (Bo=45 °) for a crossed-slot antenna mounted on top of a Space Shuttle Orbiter when the payload bay doors are closed.
229
107
Computer simulated model for a crossed-slot antenna mounted on top of a Space Shuttle Orbiter when the payload bay doors are open.
234
108
Roll conical patterns (BD:45 °) for a crossed-slot antenna mounted on top of a Space Shuttle Orbiter when the payload bay doors are open.
235
109
Computer simulated model for a crossed-slot antenna mounted on bottom of a Space Shuttle Orbiter.
238
110
Roll conical patterns (9D=45 °) for a crossed-slot antenna mounted on botto_ of a Space Shuttle Orbiter when the payload bay doors are closed.
239
quad antenna
for an axial
locations
slot mounted
on
plane patterns for a crossed-slot antenna on top of a Space Shuttle Orbiter.
xii
21g
227
Page
Figure 111
Computer simulated model for a crossed-slot mounted on bottom of a Space Shuttle Orbiter when the payload bay doors are open.
112
Roll conical patterns (8D:45 °) for a crossed-slot antenna mounted on bottom of a Space Shuttle Orbiter when the payload bay doors are open.
xiii
antenna
244
_45
I.
INTRODUCTION
If
modern
patterns
must
procedure the
meet
for
certain
of
When the far-field
near-field
cost-effectively, I_IU
most
of
the
wave
spectrum
basically
not.
there
_JOL,
I.._I
llb
approaches.
are
been
Ull
has
also
II_01
focused
which
expensive.
Thus,
following
dilemma
are
desired
but
are
much easier
to
be easily
measure
the
in
cannot
the
above
antenna
of
to
evaluate
requires
a great
following to
measure,
interest
these
in
determining
prevails:
_.,Ul
and
spectrum can
directly;
r_ll_l_,
spherical approaches
be tedious
is
and
far-field
be simply
the
patterns
cylindrical
itself
deal
drawback.
,, ,,,_a_u, _,,,_,,_.
of
design
on numerous
far-field
measured
but
been
easy
deal
each
transform
cannot
has
on plane,
an integral the
only
p_,
l_lU
However,
based
not
the
a great --I
has
relatively
To obtain
has
LJO_U
attention
it
patterns
are
system
approach
the
The conventional
aircraft
antenna
This
properly,
requirements.
and expense,
patterns
function
on a particular
a candidate
time
are to
system
measurements.
engineering
f 0........ I --I
antennas
an antenna
performance
scale-model of
aircraft
patterns
near-field
patterns
transformed
to
the
far
field. One approach of
diffraction
for
computing
and
various
wavelength. near-field accomplished,
to
(GTD). both
the
scattering
solve It
a high
near-field centers
The near-field measurement. the
is
solution
is
frequency
solution Once this
separated can
geometrical
on the
order verified
to
is
valid
when the
verification extended
theory
which
patterns
be easily
near-field
be directly
the
technique
and far-field are
can
problem
of
a by a
is the
far
field
source
without
the need of a transformation.
the near-field violated
pattern
prediction
The GTD is directly
because
in the sense that the receiver
of each isolated
specular
point.
the GTD postulates
is essentially
For instance,
be in the far field of a flat plate; yet, from each of the edge
diffraction
points
the receiver is at least a wavelength points).
Consequently,
near-field
This Fortran University
fuselage
computer code fields
77 computer
to investigate
an aircraft
airborne
is modeled
of a set of finite
mounted
removed
solve
both the
at Ohio State
ellipsoid
on
The
radiated
and in the presence
applied
geometrical
mounted
ellipsoid.
the near zone and far zone
of this code is based on the uniform
(i.e.,
diffraction
of antennas
by a composite
The analysis
not
patterns.
patterns
on a composite
flat plates.
might
that the GTD is valid
code has been developed
is used to compute
for antennas
the receiver
can effectively
the radiation
which
in the far field
it is sufficiently
antenna
to
are not
away from the isolated
a GTD solution
and the far-field
applicable
in the development
theory
of diffraction
(UTD) [1,2,3]. The code allows electromagnetic
the user to simulate
radiation
For example, the composite
problems
ellipsoid
the fuselage of an aircraft; the wings,
stabilizers,
be mounted
directly
approximated simulated
whereas,
stores,
etc.
on a ship mast.
by the composite
by flat plates.
using
a wide variety
of complex
the ellipsoid/plates
model.
can be used to accurately the plates
are used to represent
Alternatively,
the antenna
In this case the mast
ellipsoid
with
the other
Note that the plates
simulate
could
could be
ship structures
can be attached
to the
composite ellipsoid
and/or to other plates.
connected together to form a box. analyze the radiation
In fact,
the plates can be
This code is specifically
characteristics
designed to
of antennas mounted on aircraft
configurations. As with any ray optical limit
solution such as this
to the number of interactions
UTDcode, there is a
included in the field
In this case, the code includes the source, reflected,
computation.
diffracted,
and
higher order terms such as the reflected/reflected, reflected/diffracted, fields.
diffracted/reflected,
and diffracted/diffracted
The higher order terms are due to the multiple
field
interactions
between the simulation plates.
It assumesthat the
higher-order
diffracted
from the composite
ellipsoid
and reflected fields
surface are small and can be neglected.
The user may request
the code (by using the "TO:" COMMAND) to compute the higher order terms when he thinks they have a significant the code will
compute first
code can handle structures bounce back-and-forth automatically
effect
order terms only.
otherwise,
This implies that the
for which the energy does not significantly
across the target.
In any event, the code
shadowsall terms, such that if
should have been included the resulting discontinuity.
on the results;
a higher-order
pattern will
interaction
contain a
These higher-order terms are normally negligible
and can
only affect
the pattern in rather small sectors.
significant
in some region, the amplitude of the jump is associated with
the radiation the solution to indicate
However, if they are
level of the missing higher-order term. fails its
because of a lack of higher-order
failure. 3
Consequently when terms, it
tends
The code has the flexibility addition,
an arbitrary
distribution
across
approximating mounted
the distribution
The magnetic
along the magnetic orthogonal provided
direction.
that
fuselage array
can be handled
is nearly
applied dipole
flat.
to calculate arrays.
elements
direction
isn't effect
the relative
than
theory
arrays
individual
is the superposition
associated
basic
nature of the analyses.
which
is a high frequency
plate
structures
major
edges.
long.
and minor
addition,
mounted
on a
image
theory
on each dipole source
can be
as equivalent is then taken
specification.
of the contributions
with
the computer
The solution
approach.
In terms of the composite radii should
In some cases,
be at least
element
should
the wavelength
for engineering
purposes. 4
code
from each
using
from the the UTD,
of the scattering
should have ellipsoid
a wavelength
be at least limit
result
is derived
In terms
this means that each plate
each antenna
wavelength
a monopole
wavelength.
distributions
value
in the
monopole.
The limitations
wavelength
ellipsoid
[4], if the region near the
to be part of the input data for each monopole The final pattern
elements
represents
a quarter
purposes,
current
current
the current
distribution
current
for monopole
For engineering
In
have a cosine distribution
electric
by thin-wire
The relative
current
and a uniform
greater
cuts.
is done by
normal to the composite
The normal
coupling
This
pattern
provided
by a set of magnetic
current
its length
The mutual
is known.
currents
current
arbitrary
type can be analyzed
the aperture
on or electric
surface.
antenna
to handle
edges
from at least
structure
its
in extent.
a wavelength
can be reduced
In
from all
to a quarter
a
The present code requires approximately 707K bytes of storage. will
run a pattern cut of 360 points for a commercial aircraft
It
model
(Example 3, 6 plates included) with one antenna element in approximately 4 minutes on a VAX11/780 Computer. This user's manual is designed to give an overall operation of the computer code, to instruct model structures,
and to show the validity
various computed results
capabilities
of this
view of the organization
input data to a practical
points of interpreting
the input data.
structure
is briefly of the subtle
The representation
Numerouspractical
are presented in Section VI to illustrate
of the program.
Howto apply the
This includes a clarification
is discussed in Section V.
If.
to
of the code by comparing
of the input is given in Section Ill.
discussed in Section IV.
and validity
a user in how to use it
against measureddata whenever available.
Section II describes an overall The definition
view of the
of the output
airborne antenna problems
the operation,
versatility,
of the code.
PRINCIPLESOF OPERATION The analytical
predict the radiation
modeling of complex scattering
shapes in order to
patterns of antennas has been accomplished using
the Uniform Geometrical Theory of Diffraction
(UTD) [1,2,3].
high frequency technique that allows a complicated structure
This is a to be
approximated by basic shapes representing canonical problems in the UTD. These shapes include flat
or curved wedgesand convex curved surfaces.
The UTDis a ray optical
technique, and it,
gain somephysical insight mechanismsinvolved.
therefore,
allows one to
into the various scattering
and diffraction
Consequently, one is able to quickly seek out the
dominant mechanismsfor a given geometrical configuration sector.
This, in turn,
practical
leads to an accurate engineering solution
antenna problems.
the past to model aircraft structures
and radiation to
This approach has been used successfully shapes [5,6,7,8,9,10]
in
and ship-like
[11,12,13].
This section briefly
describes the basic operation of this
the analysis of antennas in an aircraft
environment.
code for
The present
version of the code allows the analysis of objects that can be modeled by flat
plates and a composite ellipsoid
the basic canonical problems. variety
of structures
structures
of which are built
up from
These shapes allow one to model a wide
in the UHFrange and above where the scattering
are large in terms of a wavelength.
the lower frequency limit
of this solution
between the various scattering practice
all
The general rule is that
is dictated by the spacings
centers and their
overall
size.
In
this meansthat the smallest dimensions should be on the order
of a wavelength. The positive time convention ejmt has been used in this code, and, all
the structures are assumedto be perfectly
conducting and surrounded
by free space. As mentioned above, the UTDapproach is ideal for a general high frequency study of aircraft structural
antennas in that only the most basic
features of an otherwise very complicated structure
need to
be modeled. determine
This
is
because
components
structures.
of
the
Components
solutions
in
geometrical
terms
of
optics
scatterer
tend
the
In
combinations
of
that
the
terms
with
the
important
higher-order computer
codes
modular
computer
up into
of
the
ray
Reference
[16]
flow
chart,
field
is
amount increasing
core
program that
approach
represent
on this
code at
is
structured
one time
swapping
various
details
is The
so that
for
the
minimized, results
segments
only
include
only
other
in
illustrated I.
code
scattered algorithms
of
a
the
is
broken
[14,15], referred
be seen
one type
reducing
of
field
One is
As can
terms in
The
thereby, then,
possible
be concerned
all
pattern
are executed.
7
and
complete
are
a given
various
routines.
all
the
various
components
Table
topic.
UTD
and tested.
is
path
the
and efficient
different
geodesic
using
from
the
need
similar
more
for
out
written
shown in
sections,
rays
accurate
various
summed with
and neglect
and shadowing
efficiency. as the
modular
to by
causing
one
to
up from
used
found
scatterers
Thus,
components
built
main
The
between
leads
are
trace
calculation
computed
of
structures
way one can
This
tracing
the
other
be systematically
are
code.
attachment
program
can
many subroutines
components, plate
that
point.
method
are
which
field
solution.
This
fields
rays
interact
the
problems
diagram
this
scattering
terms.
Complex
block
in
the
are
on and diffracted
diffracted
with
terms.
techniques
incident
individual at
higher-order
dominant
the
interact
rays
optical
field
of
terms
to
ray
cut
superimposed
of
from
the
scattered
so that
overlaying in
to
the
the and main
TABLE BLOCK
DIAGRAM
I
OF THE MAIN PROGRAM
I
SET
I
ECHO INPUT DATA READ INPUT DATA (SEE TABLE II)
•
DATA
I
YES
SPECIFY ANTENNA GEOMETRY AND DEFINE PATTERN COORDINATE INFORMATION DETERMINE ALL FIXED GEOMETRY INITIALIZE TOTAL FIELD TO ZERO
i COMPUTE VARIOUS UTD TERMS (NOTE: PATTERN LOOP IN EACH UTD TERM SUBROUTINE) a) b) c) d)
SOURCE REFLECTED DIFFRACTED FROM PLATE EDGE DIFFRACTED FROM FUSELAGE CHOPPED OFF EDGE
COMPUTE SPECIFIEDUTDTERMS a) b) c) d)
REFLECTED/REFLECTED REFLECTED/DIFFRACTED DIFFRACTED/REFLECTED DIFFRACTED/DIFFRACTED
COMPUTED SPECIFIEDLINE SOURCE ARRAY
I i
CONVERT X, Y, Z FIELD COMPONENTS TO THETA AND PHI IN PATTERN COORDINATE SYSTEM
PRINT, PLOT, AND/OR WRITE BINARY OUTPUT IN TERMS OF THETA AND PHI FIELD COMPONENTS
The subroutines structured
for each of the scattered
in the same basic way.
from the source to a particular observation Each
point using either
ray path, assuming
shadowed
First,
scatterer
scatterer
or observation
scattered
field is computed
point.
is often speeded
associated
code.
discontinuities coefficients such that included
in the main
various
to the next the
UTD solutions. This
decisions
The
shadowing based
on bounds
This type of knowledge
in the resulting
pattern;
to smooth
in the result,
the lack of its
in analyzing
solution.
When presence
or jumps
If the gliches
in the field field
is apparent.
problems.
scattered
no additional
10
the UTD diffraction
a scattered
is not
This can
Obviously,
in a
fields can be included.
of the neglected
gliches
If the gliches are small,
however,
complicated
not all the possible
the size of the so-called
leads to various
out the discontinuities
field is obtained.
In the UTD code the importance
part of the UTD
that this approach
a continuous
engineering
If it is
proceeds
program.
of the structure.
It is obvious
are designed
problem
to see if it is
is not interrupted,
of rays is a very important
be used to advantage complex
If the path
to the
possible.
The shadowing scattering
and the code
up by making
with the geometry
is used wherever
ray path.
using the appropriate
are then superimposed
are all
or diffraction.
is then checked
along the complete
the field is not computed
process
and subsequently
the laws of reflection
shadowed,
fields
components
the ray path is determined
one is possible,
by any structure
field
terms
are determined
in the pattern terms
are large,
by
trace.
are needed
for a good
it may be necessary
to
include more terms in the solution.
In any case the user has a gauge
with which he can examine the accuracy of the results led into believing
a result
and is not falsely
is correct when in fact there could be an
error associated with neglecting a higher order interaction The brief
discussion of the operation of the scattering
above should help the user get a feel for the overall better
understand the code's capabilities
term. code given
code so he might
and interpret
its
results.
The code is designed, however, so that a general user can run the code without knowing all familiar
the details
with the input/output
of its
operation.
details
which will
Yet, he must become be discussed in the
next three sections.
Ill.
DEFINITIONOF INPUTDATA The method used to input data into the computer code is presently
based on a commandword system.
This is especially
convenient when more
than one problem is to be analyzed during a computer run.
The code
stores the previous input data such that one need only input that data which needs to be changed from the previous execution. default
list
of data so for any given problem the amount of data that
needs to be input has been shortened. data is illustrated In this
The organization
of the input
in Table II.
system, all
meters, inches, or feet;
linear dimensions may be specified
in either
whereas, all angular dimensions are in degrees.
All the dimensions are eventually
11
©
Also, there is a
referred to a fixed cartesian
TABLE
II
BLOCK DIAGRAM OF THE INPUT DATA ORGANIZATION FOR, THE COMPUTER CODE
& I
-I
Initialize
Default
Read and Write
Data
Command
I
Word
TRUE
FALSE
@-T I
F
F
T
T
12
I
13
_L
F ¸
_
F
_
F
_'-_J--THETA
///"Iz /
,_J_'v
,_TT,R,, c°".
= ep
_ _y
P x
Figure
5.
Definition
of pattern
45
axis.
o
READ: a)
LFAR,R
LFAR:
This
is a logical
used to specify
variable
defined
if the far field
by T or F.
pattern
It is
is desired
or not.
b)
R:
This
is a real variable
range
in linear units
receiver. .TRUE.
E2.
COMMAND
which
is used to define
from the origin
Note R can be any number
in that
the
to the
when
LFAR is
it is not used in the calculation.
RT:
/ READ:
ITR(N),N=I,3)
/
t [ READ:
This command coordinate
system
specification Figure
enables
THZR,
PHZR,
THXR,
PHXR /
the user to translate
used to define
the input data
of the plate geometry.
6.
46
and/or
rotate
in order
The geometry
the
to simplify
is illustrated
in
the
Z z R
_R_T"×_ _
__¢_ '
x
-_"
..
i I
_Y
PHZR
YR .--_y
X
Figure
6.
Definition
of rotate-translate
47
coordinate
system
geometry.
.
READ: a)
(TR(N),
TR(N):
N:1,3) This is a dimensioned used
to specify
coordinate
line with
x,y,z
coordinates
THZR, PHZR,
THZR,PHZR:
structures.
single
corresponds
a)
the origin
THXR,
These
the real numbers
THXR,PHXR:
to N=1,2,3,
The new xR-axis
of the new coordinate
(see Figure
angles
that define
They
as spherical
xR-axis
of the new coordinate
(see Figure
and zR-axis
YR-axis
is found from the cross inputs will be made
angles
aborts
product relative
48
the
as if it coordinate
are input
that
define
system
in
the
as if it
in the reference
coordinate
6).
must be defined
If they are not, the program
system
in
6).
degrees
a radial vector
are input
in the reference
are real variables.
other.
subsequent
They
zR-axis
system
which
PHXR
as spherical
was
the
respectively.
degrees
These
being
of the new origin
was a radial vector
b)
of the new
It is input on a
are real variables.
system
It is
system to be used to input the data
for the plate
READ:
real variable.
with
orthogonal
to each
a warning.
The new
of the xR and zR axes. to this
new coordinate
All the system,
which
is
shown
redefined.
It
as
(XR,
is
always
YR,
ZR)
unless
defined
command
relative
to
"RT:" the
is
called
reference
system.
F.
Specific FI.
Terms Related
COMMAND
Commands:
TO:
@ LDERIIG, LTEST,
/ READ:
LOIIT
[
1 r_r
Ar_. L
| C._ffl
9 LI_'L/l'_
_1_
False
True
[
READ:
[
READ:
(LTRM(J),
J:1,8)
MPI, MPF, MPS
/
/
I_IIMp I, M_FIMp, /
MES(MP)
4g
MP:MPI,MPF,MPS)
.
again coordinate
and
This commandenables the user to obtain an extended output of various intermediate quantities testing
in the computer code.
the program or in analyzing the contributions
scattering mechanismsin terms of the total
I.
READ: a)
LDEBUG,
LDEBUG:
LTEST,
is ued to debug suspected
the program
within
prints
operation
variable
is associated subroutine. subroutine initial angle
They
are written
is called.
operation
50
are
used to insure one pattern
by T or F.
associated
It
with
out on unit
variables
#6
of the
out each time the
It is, also,
of the code.
is considered.
can,
set false)
The data written
with the window
with
data
data which
defined
is used to test the input/output each subroutine.
These
Only
(normally
the
#6 associated
It is, also,
of the code.
angle is considered.
This is a logical
previous
It
are
If set true,
operations.
with
by T or F.
if errors
the program.
known to be correct.
LTEST:
defined
out data on unit
then, be compared
b)
solution.
variable
each of its internal
initial
from various
LOUT
This is a logical
program
This is useful in
(normally
used to insure
Only one pattern set false)
c)
LOUT:
This is
is used
the
a logical
variable
to
data
main
insure
output
program.
proper
examine
the
(normally
READ: a)
It
defined
on unit is
also
operation. various
set
used
It
can
components
initially
be used
of
with
the
to
pattern.
false)
This is a logical
terms
are desired
(normally
variable
defined
LCORNR:
This
during
is a logical
(normally
LTRM(J):
variable
is desired
or not individual
defined
during
by T or F.
It
or not corner
the computation.
set true)
J:l,8)
These are logical specify that
It
set false)
diffraction
(LTRM(J),
by T or F.
the computation.
is used to tell the code whether
a)
to
It
LTERM,LCORNR
LTERM:
READ:
F.
#6 associated
is used to tell the code whether
b)
by T or
variables
a set of individual
are to be included
computation. following
defined
scattering
number designations:
source
field
J=2:
single
reflected
51
components
in the scattered
The components
J=l:
by T or F to
field
are defined
field by the
J=3:
single diffracted
J=4:
diffracted
J=5:
double reflected
J=6:
refl ected-di ffracted
J=7:
di ffracted-refl
J=8:
double diffracted
field
field
from chopped fuselage field fi el d
ected fi el d field
•TRUE. for 1,2,3,4 The default values are LTERM(J)= (.FALSE. for 5,6,7,8. (Note:
To get the reflected-diffracted
diffracted
field
one must accompanythis
"RD:" and/or "DD:",
.
READ: a)
MPI,MPF,MPS
MPI,MPF,MPS:
These
are integer
MPF = final
plate,
to final
MPI=I,
included
a)
MPF=3,
to define
and MPS=2
the
where
plate
MPS = increment
(Note:
variables
used in the computation,
MPI = initial
READ:
commandwith COMMAND
respectively.)
plates
.
and/or double
and
in plates
going
from initial
plate,
imply
plates
1 and 3 are
in the computation.)
(MEI(MP),
MEF(MP),
MES(MP),
MEI(MP),MEF(MP),MES(MP): variables plate 52
These
MP=MPI,MPF,MPS) are dimensioned
to define
the edges
used in the computation,
integer
on the MPth where
MEI(MP)= initial
edge on plate MP
MEF(MP)= final
edge on plate MP, and
MES(MP)= increment in edges going from MEI(MP) to MEF(MP).
F2.
COMMAND
RD:
/ READ:
•
NRDX
/
/ DO 5622 NRD:I,NRDX
[ READ:
MPIRD(NRD),
MP2RD(NRD)
/ 5622 CONTINUE
I.
READ:
NRDX
NRDX:
This
is a real variable
reflection-diffraction 0 < NRDX < 40.
53
I
/
/
used to specify terms
desired.
the number Presently,
of
o
READ:
MPIRD(NRD),
MPIRD(NRD):
MP2RD(NRD)
This is an integer
specify
the plate
number
dimensioned from which
array
used to
the first
reflection
occurs. MP2RD(NRD):
This
specify
is an integer
the plate
number
dimensioned from which
array
used to
the diffraction
Occurs,
(Note:
F3.
The usage of this command
COMMAND
is illustrated
in example
2.)
DD:
@ i /
"
READ:
NDDX
/
[ DO 4022 NDD=I,NDDX
/
l / READ:
MP1DD(NDD),ME1DD(NDD),MP2DD(NDD),ME2DD(NDD)
/ 4022 CONTINUE
54
/
/
READ:
.
a)
NDDX
NDDX:
This
is an integer
number
of double diffraction
Presently,
READ:
.
a)
MPIDD(NDD),
MPIDD(NDD),
variable
terms
the total
desired:
O < NDDX < 10.
MEIDD(NDD),
MEIDD(NDD):
arrays
that specifies
MP2DD(NDD),
These
used to specify
respectively,
ME2DD(NDD)
are integer the plate
dimensioned
and edge
number,
from which
the first
diffraction
,
I=
U
occurs.
L_
u)
I_Ii_CUU_
|_UU)
,
I'lr
arrays
CUU_I_U
J
I 11_3C:
used to specify
respectively,
from
which
OI
I ilI.,C_CI
the plate a
second
I II1_;11_
I VIl_..u
and edge number, diffraction
Occurs.
(Not e:
The usage of this command
F4.
COMMAND
This default
command
case.
is illustrated
in example
2.)
RS: enables
There
the user to reset
is no input
the input
data associated
55
with
data to the this
command.
G.
Execute GI.
and Output
COMMAND
Related
Commands:
LP:
I / READ:
This the total
Io
command enables
LWRITE /
the user to obtain
a line printer
of
fields (Eop, E@p).
READ: LWRITE:
LWRITE This
is a logical
used to indicate
variable
defined
if a line printer
or not.
G2.
listing
COMMAND
PP:
/ READ:
LPLOT
/
i / READ:
PLTNUM,
56
RADIUS,
IPLT
/
by T or F. output
It is
is desired
This commandenables the user to obtain a pen plot of the total fields
(Egp, E@p). 1.
READ: LPLOT LPLOT:
This is a logical
variable defined by T or F.
is used to indicate if
It
pen plot is desired or
not.
.
READ: a)
PLTNUM,
PLTNUM:
RADIUS,
This
IPLT
is a real variable
of polar
plot desired,
used to indicate
the type
such that
f
PLTNUM
=
I÷E-THETA
and E-PHI
are plotted
separately.
2÷E-THETA
and E-PHI
are plotted
in the same
plot. 3÷Both
b)
RADIUS:
This
is a real variable
the radius
c)
IPLT:
1 and 2.
of the polar
This
is an integer
type
of polar
IPLOT
=
that plot.
variable
plot desired,
that
indicates
such that
1 ÷ field
plot
2 ÷ power
plot
3 + dB plot
57
is used to specify
the
G3.
COMMAND
BO:
/ READ:
This complex wishes might
command
enables
to input the aircraft
code
be useful, for example, individually,
appropriately
adjusting
In this way numerous aircraft
I.
results
to study
and then
array patterns
This
output
output
into another
array
patterns.
process
the array
the amplitude
READ:
and phase
of each
can be obtained
of the
is useful program.
if one This
One can run each pattern
by
element
without
pattern.
running
the
LBOUT
LBOUT:
This
is a logical
COMMAND
This command may be computed.
variable
defined
is used to indicate
if thebinary
or not.
format
source
command
values.
a binary
code excessively.
a)
G4.
/
the user to obtain
E-THETA and E-PHI patterns
array element
LBOUT
The output listing
by T or F. output
is specified
It
is desired within
the
of the code.
EX: is used to execute After execution
word. 58
the code so that the total
the code
returns
for another
fields possible
This concludes the definition
of all
the input parameters to the
program. The program would, then, run the desired data and output the results
on unit #6.
definition
However, as with any sophisticated
of the input data is not sufficient
understand the operation of the code. difficulty
program, the
for one to fully
In order to overcome this
the next section discusses how the input data is interpreted
and used in the program.
IV.
INTERPRETATION OF INPUTDATA This computer code is written
information
to require a minimumamount of user
such that the burden associated with a complex geometry will
be organized internal need not instruct
to the computer code.
For example, the operator
the code that two plates are attached to form a convex
or concave structure.
The code flags this situation
two plates have a commonset of corners (i.e.,
by recognizing that
a commonedge).
So if
the operator wishes to attach two plates together he needs only define the two plates as though they were isolated. will
have two identical
corners.
However, the two plates
All the geometry information
associated with plates having commonedges is then generated by the code.
The present code also will
plate as shown in Figure 7(a). defining
allow a plate to intersect
another
It is necessary that the corners
the attachment be positioned a small amountthrough the plate
surface to which it intersecting
is being connected.
Note that the edges of the two
plates should be no closer than a quarter wavelength.
5g
In defining the plate corners it subtlety
is necessary to be aware of a
associated with simulating convex or concave structures
which two or more plates are used in the computation. results
in that each plate has two sides.
simulate a closed or semi-closed structure, of the plate will
be illuminated
in
This problem
If the plates are used to then possibly only one side
by the antenna.
Consequently, the
operator must define the data in such a way that the code can infer which side of the plate is illuminated
by the antenna.
This is
accomplished by defining the plate according to the right-hand one's fingers of the right the order of their illuminated
definition,
his thumb should point toward the To illustrate
this constraint
associated with data format, let us consider the definition
specified
In this case, all
such that they satisfy
pointing outward as illustrated satisfied
As
hand follow the edges of the plate around in
region above the plate.
rectangular box.
rule.
for a given plate,
of a
the plates of the box must be
the right-hand rule with the thumb in Figure 7 (b).
If this
rule were not
then the code would assumethat the antenna
is within the box as far as the scattering
from that plate is
concerned. In the "PG:" command,if
LATACH(MPX)=T (i.e.,
the plate is attached
to the fuselage), the program assumesthat the first
and last plate
corners (PVC(N,1,MPX)and PVC(N,MCMX,MPX)) are to be attached to the fuselage.
The user must define the geometry accordingly.
The plates can be attached to the ellipsoid Figure 7(c) and (d). half of the ellipsoid,
as illustrated
in
However, when the plates are attached on the lower the y componentof the first 60
and last
corners are
set equal to the y dimension of the ellipsoid Figure 7(e) and (f).
It is important to note that the user need not
exactly attach the first code will
center line as shown in
and last corners to the fuselage because the
extend the edges and reset the first
and final
corner points
on the fuselage as shown in Figure 7(g). In the "FG:" command,the composite ellipsoid two ellipsoid
is constructed from
sections positioned back to back and connected together
such that its surface is continuous and smooth at the cross-section the source location.
The composite ellipsoid
semi-major/minor axes are
defined by AX, BX, CX and DX. The source location Cs-
The case in which
coordinate assumed
system
the source
origin
is positioned
(Zs positive)
as shown
is defined by Zs and
to the right in Figure
here that both the right and left ellipsoid
are coincident. and the source
Then, the location
right side ellipsoid
are defined
of
of the
8(a).
coordinate
semi-major/minor
It is systems axes
as
(aF, bF, CF, Ves, Vrs) = (AX, BX, CX, Ves, Vrs)
where
AX sin (¢s) Ves = • arcsin
The parameters
(Zs/CX)
and
BX cos (%)
for the left side ellipsoid
AX cos (Yes) aF =
Vrs =
cos ( V_ s )
61
are given
by the following:
BX cos (Yes)
I
bF =
I
cos (Yes) and I
cF = DX + Zsh
where
I
Yes
=
arcsin
Ill ]-'-i CX cos Ves +1 tan (Ves) (DX + Zs)
and I
Zs - DX sin (Yes) Zsh = 1 + sin (Ves)
Note that Zsh is the distance coordinate
origins
axes
the source
as shown in Figure
and source location
i
i
the
right and left ellipsoid
as shown in Figure 8.
For the case when negative
between
8(b),
is to the left of the origin the left ellipsoid
are defined
as
i
(aF, bF, CF, Ves, Vrs) = (AX, BX, DX, Ves, Vrs)
where
AX sin (¢s)
Zs
Yes = arcsin
The parameters
(_--_)
and
Vrs = BX cos
for the right ellipsoid
62
(¢s)
are given
by
(Z s
semi-major/minor
AX cos aF
=
(Yes) I
cos
(Ves)
BX cos (Yes) bF =
!
cos (Ves)
and
cF = CX - Zsh
where
l-F
' V
= arcsin
I i
DX cos Ves
_ t_n
V__
([_._(+
and !
Zs - CX sin (Ves) Zsh =
!
I + sin (Ves)
63
-1 7_]
l I
4
I
3
y
I/ Figure
7(a).
Data format used to define another flat plate.
J
a flat plate
intersecting
|
f Figure
7(b).
Data format
used to define
64
a box structure.
(c)
_uj
(e)
(f)
Figure
7(c)-(f).
Fuselage and wing geometries for aircraft looking from the front. The antenna is on the top portion of the models.
65
model assumed
to
be
_Z
X
ANTENNA
Figure
7(g).
Data format fuselage.
2
used to define
66
a flat plate
attaching
to a
_(3L'_
WHEN
ZS
_> O )
• If,
It'
AF'AX,BF'BX,
C]_
WHEN
ZS
CF'CX
< O,
LEFT
ELLIPSOID
AFP 4 i
AFP
Figure
8.
Composite fuselage.
• AX,
ellipsoid
RIGHT IX"
BFP • BX,
geometry
67
ELLIPSOID
CFP
• D,K
simulating
the aircraft
Using the "SG:" 90 °.
command,
In case the antenna
the user must redefine the required angular
it is necessary
is placed
the geometry
range.
This
that
on the bottom such that
requires
-90 ° _ PHS(MS) part of the fuselage,
Cs PHS(MS)
turning
falls within
the aircraft
upside-down. The code simulates this
command
fuselage zero. this
is activated,
blockage
plate.
way.
It is assumed fields
neglected.
Thus,
structures absence
dimensions
PROGRAM
it must
"FB:"
set that
of the fuselage
are not added
inthe
If
if a ray strikes field
component
in which
interactions
a
to
can be simulated
diffraction
are small
higher-order
COMMAND.
in
and
case they
are
between
in the computation,
their
results.
be kept in mind that
away from any diffracting
the antenna edge.
should be kept at
In fact all
should be at least a wavelength.
OUTPUT
option
of the results.
automatically
values
by using
that the higher-order
even though
The basic output listing
effect
from the fuselage
will be apparent
least a wavelength
will
If so, it will
and the fuselage
Finally,
blockage
the code will determine
Thus, the shadowing
reflection
V.
fuselage
If LWRITE=T
generate
as shown in Figure
the Eop and E@p radiation
from the computer
9.
in the input data
a line printer Recall
pattern
68
code is a line printer
output
the program
of the complex
that the results
values.
list,
In order
field
of the program
to again
describe
are
these pattern components, let us consider the various principal patterns treated in the previous section. a rotation
plane
The computer code allows for
of coordinates such that one can take a pattern about the
spherical angles (THC, PHC). The geometry that applies for each of the roll,
elevation,
illutrated
and azimuth patterns used in the next section is
in Figure 10.
relative
to the rotated
and PHC are changed.
Note that the ep and pattern
Thus,
coordinates
@p angles
are defined
and that they
Eep is the theta
component
change
as THC
of the field
+^
(i.e.,
+^
Eep=E.e p) in the pattern
The total
radiated
In addition
electric
"PP:" command, patterns.
routine
output
#11,
one by one (i.e.,
another
automatically
maximum
in each
i.e., WRITE #12, #13,
useful output
when
(11).
This
in the next output
list,
using
the
ring
polar
plot
section. of the Eep and
using the
"BO: '°
the Eep and E@p results
Note that this
unit number
additional
one wishes to interface
69
list,
the outer
case.
write
...) for each
one.
data
of obtaining
plot the Eep and E@p polar
is to get the binary
automatically
E@p=E-@p).
by _.
are plotted such that
option
will
Likewise,
results, one has the option
If LROLIT=T in the input data
the program
number
a very
is denoted
was used to plot the data presented
E@p patterns.
unit
will
to the pattern
One more
command,
patterns
system.
If LPLOT=T in the input
the program
These
corresponds
field
to the printed
a set of polar patterns.
coordinate
execution.
this program
on
increases This with
is
Poor
• +oe**o.
• *lice
• leeeeeee,
.1
• ___________e_++___e____e___eo__e+__ee__e___ee__eee__o__oe__e_oee__ooeoo_e__________e______-
col
:.........
:.... ............... ; :.............
. .......... : ........
• :
eOTITT0
lllr
C_B,IUIt5
Vl
oelee
• *l*
Figure
I'U¢
•
•
lemeqq+
-OeN+ll -I. IIPII -I.IIIA -I+IIII+ -O.0++_+ *3.+0111 l.ml+_+ +.qllel 1.0+llq I.+AIIA
* De * eel*loll
*o *lllOllllll
9(a).
: .....
;_ "' .... . : " _IC
•
•
...
: , • ...... :,.;..: . , •
++0eeq5
• * l_r_l.
_I.IIOP0 i'l.++Oeq +_.0_IAC lAle0Olt0 l-_.10)t! +Pm._ml+l 0_/.Jvl+C _'A._ oo+d 5omo+_p+? _l.l+ll+
* *oeeoo*lee*
• • *lille
; : ;
qlll
P+.+I+iO O+.IOul! lq.m+Jll Pme'0dil Pe.Olll+ Pq.+OOql l+**+d+Ol P+.+5_ll Pm.mlO+l Im.+d+dl
..
...... ": ..... : .. ........ ..
oil|
:...... ; : •
•
+ r
*loIPlI!
-ll++OAlll
-O.+lI*l -I.1+141 *I.10751 -O.++?tA -l.10+ll "q.++lq+ -ImPOl_ *l*IPll+
-l+O.Ol+++ -IP_.IR+I+ -I+6.N4+?$ -42.q+1++ -_+.A+'_+ -+l*l+k/14 -46*_q5++ *++,+?716
IPlllmlklLll£0 + lUalglllllnr
output
70
;
...
1.181_I 1.I+2;I l.+e+91 1.1Ollq +*l)?l& l*Im?lq 1.14+11 1.14+19 q.Olg|+ l*l+ll+
iqomsLiE£_ N
-lh+llq+ *tJ. JSlll *SI.ITIOl -S$.+$++'. -S).+llPl -+1.+6_14 *S+.llq+l +qseqqA+q -qJ*SqqPl -S$o+qSP_
llllqllUg[
Ill
l.ll)?l 1.6lltl l.A&l+l O*i%*l 1.151A6 q.lltl+ l.Aq+%5 l*llq_l l*&+ldl O.A)el+
*$.11+11 -I.SC*+I -+.+n_PI -1.m'0114 -+.IIMI/ *t.l_q+'l *+.n*lql *]*q*lP4A +++'l'J/+l *q.0ll4+
ell*
• lllOlllllitlllllllOIOOlllllllOeloIllllOlllltlllllllltllllllOllllltlillllllOll
Line printer
*
....
)
* **oeoeooooeeeoloeoolooeooeleeoeooeeoooooeoeoooloooloooloooeoeoleooeeoleo
• Ill
;..... .:.
. , • ................ .* ; .
for the EBp fields
00 • * * 10 .•
• Ill*lll
of Example
I.
61 , **
Oil
• •
GE;G;;'_,L
PAGE
IS
POOR qUALITY
......... • :
: .... : :
• •=e•••
•
•
mO1itED
CGOR2|MAI£S
|HLI& --*.--**--
Figure
Pil! - .........
9(b).
..
i
: ............. :
•
IfNC
•
iill
: : ••o
: ••
••
•
Oo||OOO
Qe•
: . :i ": 4leo
.
I
PHC
••JoeDe
: •
Line printer
....
•• •
••Q•
••0
eo •
leoea•
•
ee•
eoe
:
:
:
•
04 • •eel
•
•
' : ' • •" .... ": ,.• •
• e•
0.1==0'1J
f-nN| *°...o.°...°......
••Q•
q
....
output
71
P_J_C .. ....
UNM01NiLI_[O N&G_|IUG£ ***********************
fll
for the E@p fields
......
hn_NiLll_O H&GN|TSJfl_ °..°° .......
of Example
DiS . ....
1.
,Xp"
Yp (O)
ROLL
PLANE
COORDINATES
(THC-O
°,PHC,Oe)
X
A
_p (b)
Figure
ELEVATION
10.
Transformed cuts.
PLANE
COORDINATES
coordinate
72
systems
Zp
(THC-90
e, PHC-
for the conical
90 ° )
pattern
^
Yp
(c)
Figure
AZIMUTH
10.
PLANE
COORDINATES
(Continued).
73
(THC=9OQ,
PHC ,O°)
Vl.
APPLICATION OFCODETO SEVERAL SIMPLEEXAMPLES The following two examples are used to illustrate
somefeatures and
demonstrate the usage of the basic COMMANDS of the computer code. effect
of higher order terms in the solution
The
is shown in example 2.
Note that the patterns are plotted in decibels with each division 10 dB and that the labeling
being
is not included.
Example 1. Consider the radiation
pattern of an antenna mounted on a
composite ellipsoid
for different
example illustrates
the usage of the COMMAND "FC:'° and its
effect
on the pattern.
pattern cuts.
This
The geometry is shown in Figure 11.
X
5_
l
. MONOPOLE
v
J_
6o), Y
sX. (o)
SIDE
VIEW
MONOPOLE Y. (b) Figure
11.
A monopole
TOP
VIEW
mounted
on a composite
74
ellipsoid.
z
The input data
is given by:
5.,6.,60.,20. F O.rO.eO. 25.,3. 1 0.,0. ;4,.8,0o,o25,3 1.,0. PD- _ _ 0.,0.,90. 0,360,1 T,1000. PP= T
(FAR FIELD)
IX= PI):_IMb'I}I 1_ (FAR FIELD) 9¢.,0.,90. 0,360,1 T,1000. IX= PD: 12_VATION PLANE (FAR FIELD) 90.,90.,90. 0, 360,1 T,1000. IX: SG." MONOI_LE 25. ,-10. I 0.,0. :4, •8,0., .25,3 1.,0. IX: FC" FUSELAC.E (3DPR_ OFF F,T 40. ,-14. IX-
The computed
results
are shown
in Figure 12.
75
(a)
ec=O °,
¢c=0 °,
(b)
ep=90 °
(c}
ec=90 °,
12.
¢c:0 °,
ep=90 °
ep=gO °
(e)Oc=gO °, @c:gO °, Op=gO °
(d) ec=90 °, @c=90 °, Op=90 °
Figure
@c:gO°,
ec=90 °,
Radiation pattern of monopole mounted on a composite ellipsoid at frequency .3 GHz. (a) (b) (c) source located at PHS=25 °, ZS=3_ (d) (e) source located at PHS:25 °, ZS:IOX and fuselage chopped off at ZC2:-14_ for (e).
76
Example
2:
Consider
the roll plane
radiation
pattern
attached
to a composite
ellipsoid
(5' x 6', 50' x 50').
geometry
is shown in Figure 13.
"PI:" commands will
and their effect
be shown in this
in the computation
Figure
13.
A bend
example.
The usage
77
of "TO:"
on the radiation Various
are shown in Figure
plate attached
for a bent
to a composite
GTD terms 14.
ellipsoid.
plate The
and
pattern involved
source field
reflected
diffracted
refl ected-refl ected field
field
Figure 14. Various GTDterms.
78
field
refl ected-di ffracted field
di ffracted-refl field
diffracted-diffracted
Figure 14.
(Continued).
79
field
ected
The input data
is given by:
I._l: 2 1_: 1GBz 1,1.,1. FG: 5. ,6.,50.,50. F 0.,0.,0. FB: 2 4 4.5,0.,20. 4.5,0.,-20. -4.5,0. ,-20. -4.5,0.,20: 4 0.,-5.5,20. 0.,5.5,20. 0.,5.5,-_0. 0.,-5.5,-20. SG: MONOKLE 0.,0. 1 0.,0. .4,.8,0.,.25,3 I.,0. PP: PEN RXE T 1,1.35,3 PD: RDLL PLANE (I_AR 0.,0.,90. 0,360,1 F,1000.
DDs
4 2,4,2,2 1,4,2,2 2,2,1,4 2,2,2,4 91): TOTAL FIELD (IN_IEE F,F,F T,T T,T,T,F,T,T,T,T 1,2,1 1,4,1 1,4,1 EX: _I): S(XIR_ FIELD OL_Y ¥,F,F T,T T,F,F,F,F,F,F,F 1,2,1 1,4,1 1,4,1 EX: '1"O: REFLBCTED FIELD ONLY F,F,F T,T ¥,T,F,F,F,F,F,F 1,2,1 1,4,1 1,4,1 EX: '1"O: DIFFRACTED FIELD ONLY ¥,F,F T,T ¥,F,T,F,F,F,F,F 1,2,1 1,4,1 1,4,1 EK: •O: S+R F,F,¥ T,T T,T,F,F,F,F,F,F 1,2,1 1,4,1 1,4,1
FIELD)
4,T 3., 6 •,-20. 3.,9. ,-20. 3.,9.,20. 3.,6.,20. I:G, 4,1' 3.,9. ,-20. 10.,18.,-20. 10.,18.,20. 3.,9.,20. 1_: 1 1,2 8O
IDUBLE
TIRMS)
•O: S+R+D (C_IL¥FIRST OI_ER TERM ¥,F,F T,T T,T,T,F,F,F,F,F 1,2,1 1,4,1 1,4,1
F,F,F T,T F,F,F,F,T,F,F,F 1,2,1 1,4,1 1,4,1 EX: TO_ S+R+R/R F,F,F T,T T,T,F,F,T,F,F,F 1,2,1 1,4,1 1,4,1 EX: TO: REFLECTI_DIFFRACI'IGN F,F,F T,T F,F,F,F,F,T,F,F 1,2,1 1,4,1 1,4,1 EX: TO: R/R+R/D F,F,F T,T
_)
TERM (R/D)
F, F, F, F,T, T, F, F 1,2,1 1,4,1 1,4,1 EX: TO: S+R+D+R/R+R/D F,F,F T,T T, T, T, F, T, T, F, F 1,2,1 1,4,1 1,4,1 EX:
81
20: DIFF_£TIC__IOH F,F,F T,T F,F,F,F,F,F,T,F 1,2,1 1,4,1 1,4,1
T_M
(D/LU
TO: S+R+D+R/R+R/D+D/R F,F,F T,T T,T,T,F,T,T,T,F 1,2,1 1,4,1 1,4,1 EX: •O: DOUBLE DIFFRACTION
TERM
(D/D)
F,F,F T,T F,F,F,F,F,F,F,T 1,2,1 1,4,1 1,4,1 EX: •C): D/R+D/D F,F,F T,T F,F,F,F,F,F,T,T 1,2,1 1,4,1 1,4,1 20: ALL _UBLE TE_ F,F,F T,T ¥,F,F,F,T,T,T,T 1,2,1 1,4,1 1,4,1
F,F,F T,T T,T,T,F,F,F,F,F 1,2,1 1,4,1 1,4,1
82
PI: _U_E OPP SE(I]_ 1 PG: ADD ONE HATE 4,T 3.,-6.,20. 3.,-9.,20. 3.,-_.,-20. 3.,-6.,-20. PP: T 1.,2.,3
R2tTE
The computed each
pattern
results
in Figure
can see the relative is shown in Figure superimposed.
However,
Therefore,
higher
added to eliminate 15(a).
execution another
regions
to the same
of each term.
which are in Figures The final
as shown in Figure
is modified
as shown in Figure
terms
16.
83
by removing
is still
is far in the are rough.
15(g) to 15(p) result
are
Optics"
the GO solution
of the GTD solution
It is clear that these higher
the geometry
"Geometrical
15(f), the pattern
result
field
from the discontinuities
order terms
the discontinuities.
of the pattern
so that one
An interesting
form the classical
in Figure
order terms
level
Note that
the source and the reflected
as one can observe
as shown
15 and 16.
one should note that
Even when the first
superimposed,
certain
significance
15(e) where
from being complete
Figure
15 is normalized
These two terms
(GO) solution.
pattern.
are shown in Figures
are
is shown
in
can be significant 15(p).
one plate
In the last and adding
in
(a) total solution (S+R+D+R /R+R/D+D/R+D/D )
(b) source
(c) reflected
(d) diffracted
Figure
15.
field
(R)
Roll plane
radiation
84
pattern.
field
(S)
field
(D)
C_;_;_'A"
PAGE' IS
OF POOR QUALri'y'
(e)
S + R
(f)
S + R + D
(g)
reflected/reflected field (R/R)
(h)
S + R + R/R
Figure
15.
(Continued).
85
(j) R/R + R/D
(f) reflected/diffracted field (R/D)
) (1) diffracted/reflected field (D/R)
(k) S + R + D + R/R + R/D
Figure 15.
(Continued).
86
(m)
S + R + R/R + R/D + D/R
(n) diffracted/diffracted field (D/D)
( (o) D/R + D/D
Figure
15.
(p) second order interaction GTD terms (R/R + R/D + D/R + D/D)
(Continued).
87
(a)
(b)
Figure
16.
Total solution commands,
(S+R+D)
88
after
using
"PI:" and "PG:"
VII.
APPLICATION
To begin set
of
any
scale
ellipsoid
structures
such
"COMMAND FC:" constructed
low
ellipsoid
parameters
should
simulate
antenna
the
location.
This
code
allows
for
requires
as the identical
consecutive
program pairs on both
two
edge
identifies
as commercial,
shuttle the
first
radome
it
is
are
given
use
u_pau,,,_x,
finds The
accurately
is
assumed
in
the
the a,,,,
composite
ellipsoid
surface
as possible dimensions
methods edge
attachment,
this Note
as
which
mode of that
means there
R9
for
near
are
defining
attachment
edge be defined
corners.
plates
such
models
ellipsoid
edge to
a plate
of
as
different
I)
Edge to that
The
the
specified
model.
another:
attachment.
17 often edges
to
the
the
that
fuselage.
composite
to
use
such
one
aircraft
Once the added
a
solution.
procedure, the
also
a
other
material
illustrate
surface
are
be attached
to
fuselage
plates
surface
two
for
the
aircraft.
space
numerical
simulation
of
the
computer
serve
with
calculations.
and the
iney
the
these
aircraft
general
of
One can
start
consists
simulating
etc. part
to
model
plates
constant in
one needs
aircraft
flat
radome
aircrafts
this
To begin
plus
the
of
examples, of
A typical
dielectric
variety
military
validity
to
model
an aircraft,
stabilizers,
transparent
A wide
the
drawings.
as wings,
of
following
of
fuselage
to
be totally
private,
simulation
model
composite
to
OF CODE TO AIRCRAFT SIMULATIONS
and 2)
illustrated
as two attachment
the
one plate
corners actually
or
edge in
three only
must exists
to
Figure colinear
by
finding
be an edge
Figure
between
them.
17.
Edge to edge plate
In the case to surface
as penetrating
a short distance
as illustrated
in Figure
18.
Here
care must be taken to assure contained
the smaller
within
than a quarter wavelength
._,
portion
then
of plate
edge
is nearer
#2.
NEW JUNCTION
d_ 2
PLAT
18.
#2.
PLATE_
PLATE_
Figure
plate
#2, and no where
or so to an edge of plate
plate
the new junction
#1 behind
that the new junction
the bounds
is defined
of the second
defines
of plate
INTERSECTION__.._\//
PLATE
one plate
the surface
The program
and eliminates
completely
attachment,
through
edge
attachment.
Edge to surface
go
plate
attachment.
/
,'_
///
/
One thing which should stabilizers, computer about
and plates
as illustrated
generating
be noted is that the attaching
to the fuselage in Figure
the correct
7(g).
is automatically Thus,
done by the
the user need
input data to perform
91
of the wings,
this task.
not worry
Example 3: Simulation of Boeing 737 In this example, monopole and slot fuselage of a Boeing 737 aircraft
antennas are mounted on the
at various stations
as shown in Figure
19. A
),/4monopole
shown in Figure 19.
mounted
at station
The line drawing
220 just above
the cockpit
of the 737 is shown
and the computer model based on the input data
is shown
in Figure
in Figure
The input data is as follows:
PG: VERTICAL STABILIZER 4,T 77.,0.,48}.19 284.147,0. ,683.696 284.147,-8.2.5,819.056 77.,-8.2.5,618..5.5 PG: NOSE 4,T .5.5,-10.,-308.56 -.1 ,-10.,-321.6 -.I ,0.,-321.6, '5 .'5,0 • ,-308 .'56 PG: NOSE 4,T 5.'5,0.,-308.56 -.1,0.,-321.6 -.1,10.,-321.6 .5.'5,10.,-308 .'56 PP: POLAR PLOT IN DB T 1,1.'5,3 PO: ROLL PLANE 0.,0.,89.8 • 0,360,1 F,6000. EX= PO" ELEVATION PLANE 90.,90.,89.8 0,360,1 F,6000. EX=
UN: I NOES 3 FQ: 3.18 GI-iZ 1,3.18,1 . FG: BOEING 737 (STATION 220) 77.,74.,830.,308.56 F 0.,0.,0. SG: HONOPOLE 0.,-278. I 0.,0. t .'537 ,} .074,0 •, • 928.552.5,3 I .,0. PG: RIGHT WING 4,T 1 • ,75.,67.952 1 .,536.93,316.14 1 .,'536.93,37 9.86 1 .,75.,240.26 PG: LEFT WING 4,T 1 .,-7'5.,240.26 1 .p-'536.93,379.86 I .,-'536.93,316.14 I .,-75.,67.952 laG: VERTICAL STABILIZER 4,T 77.,8.25,618.'5'5 284 •147,8.25,819.056 284.147,0.,683.696 77.,0.,483.19 92
as 20
21.
I_: AZIMUTHPLANE
I'D: AZIXIJTHPLANE
93.,0.,89.8 0,360, I F,6000. EX: P9: AZ I _ITH PLANE 93., O., .50. 0,360, I F,6000. EX: IR} • AZ I XUTH PLANE 93.,0.,60. 0,360, I F,6000. EX: PD: AZ I MUTH PLANE 93.,0.,70. 0,360,1 F, 6000. EX:
93.,0.,80. 0,360,1 F,6000. EX: PD = AZ I HUTH PLANE 93 .,0., | 00. 0,360, I F,6000. EX: P0: AZ I HUTH PLANE 93.,0.,I 10. 0,360,1 F,6000. EX: PD: i_ I NUTH PLANE 93.,0.,120. 0,360,1 F ,6000 • EX:
The three
principle
plane
results are shown
found to be in very good agreement work
was performed
using
a 1/11th
the measured attributed normal
or the movement This
to the nose section
patterns,
staff
some asymmetry
at NASA
of the model
with
(Hampton,
due to shifting
from the actual surface plane
This
weight
normal)
in the comparison
with
axis rotated
3° to the nose
in the following
pattern
calculations
for the
computed calculated
and shown results
plane patterns in Figures compare
for this
25(a) to
(g).
very favorably g3
Station
antenna In each
with
be
the
3° tilted by the
patterns.
measured
pattern
azimuth
during
plane
the conical
various
could
was detected
azimuth
that
to the surface
(approximately
pattern and various
this misalignment
Virginia)
It is noted
respect
of the monopole
22 to 24 and
The experimental
in the patterns.
of the monopole
misalignment
evaluation
To compensate
The
have
to misalignment
calculated
with measurements.
scale model of a Boeing 737 aircraft.
results
measurement.
used
by the technical
in Figures
section
220 case.
location case,
was
are
the
the measurements.
ANTENNA
A
LOCATION
A -
STATION
220
B -
STATION
250
C -
STATION
505
D -
STATION
222
E -
STATION
950
B C
Figure 19.
Test locations for the antenna installation on the Boeing 737 aircraft.
94
(o)
(b)
FRONT
SIDE
VIEW
(c)
Figure 20.
VIEW
Boeing 737 aircraft.
95
TOP
VIEW
(o)
(b)
FRONT
(c)
Figure 21.
SIDE
VIEW
VIEW
TOP
VIEW
Computer simulated model of a Boeing 737 aircraft. antenna is located at Station 220.
96
The
Irp
-----
CALCULATED
---MEASURED
TOP
LEFT NING
RIGHT NING
BOTTOM ISCFILEs
Figure
22.
ERCH
Roll plane pattern on top of a Boeing
DIVISION-tODB)
of a >,/4 monopole 737 aircraft.
97
mounted
at Station
220
------
CALCULATED
---
MEASURED
TOP
NOSE
TRIL
BOTTON (SCRLEs
Figure
23.
ERCH
OlVISION-IODB)
Elevation plane pattern of a _/4 monopole 220 on top of a Boeing 737 aircraft.
98
mounted
at Station
CALCULATED #p • 9o"
---
MEASURED
NOSE
LEFT NING
RIGHT NING
TRIL ISCRLEz
Figure
24.
Azimuth plane 220 on top of
ERCH DIVISION-IODB)
pattern of a _/4 monopole a Boeing 737 aircraft.
99
mounted
at
Station
NOSE
LEFT MING
...---
CALCULATED
---
MEASURED
RIGHT WING
ISCRLE=
DIVISION-IODB)
NOSE
TRIL
(o)
ERCH
8p = 50"
LEFT NING
TRIL
(b)
Figure
25.
8p • 60 °
Azimuthal conical patterns of a L/4 monopole Station 220 on top of a Boeing 737 aircraft,
100
mounted
at
NOSE ------
CALCULATED
---
MEASURED
RIGHT MING
LEFT N[NG
ISCALEs
TRIL
(c)
ERCH
NOSE
8p - 70 °
LEFT WING
]GHT ING
TAIL
(d)
Figure
25.
DIVISION-IODB)
(Continued).
101
8p • 80 °
NOSE
LEFT
MING
|
_.lf
f
/r_//_
"--
CALCU
L ATED
---
MEASURED
_I:iIGHT
_MING
ISCALEz TFIII,,,
(e)
25.
DIVISION-IODB)
NOSE
ep- IOO"
LEFT NING
Figure
EACH
RIGHT NING
(Continued).
102
-----
CALCULATED
---
MEASURED
NOSE
'I'RIL ISCRLE:
(g)
Figure
25.
ERCH
DIVISION-]ODB)
8p • 12o"
(Continued).
103
The next two cases,
a _/4 monopole
305 on top of the fuselage
is mounted
of the Boeing
at stations
737 aircraft.
250 and
The input
data
is as follows:
UN: 3
INCHES
PG= NOSE 4,T 3.5,-I0.,-308.36 -.1 ,-10.,-321.6 -.1,0.,-321.6, _.5,0.,-308.56 PG: NOSE 4,T ._f,0.,-308.56 -.I ,0,-321.6 -.I ,I0.,-321.6 5.5,10.,-300.56 PP: POLAR PLOT IN DB T 1,1.3,3 PO: ELEVATION PLANE 90.,90.,90. 0,360,1 F,6000. EX:
FQ: 3.18 GHZ I ,3.18,1. FG: BOEING 737 77.,74.,830.,308.56 F 0.,0.,0. SG: MONOPOLE (STATION 250) 2.9_-248. ! 0.,0. I .537,3.074,0.,.92852_,3 1 .,0. PG: VERTICAL STABILIZER 4,T 77.,8.2_,618.55 284.147,8.25,819.056 284.147,0.,683.696 77.,0.,48J .1 9 PG: VERTICAL STABILIZER 4,T 77.p0.,48}.19 284.147,0.,685.696 284.147,-8.2_,81 9.0_6 77. w-8.2_,618.P5
The only difference monopole
is at station
geometry.
in the input
data for the case when the
305 is in the specification
The sourc_ geometry
for station
following:
SG: MONOPOLE 737 (STATION 0.,-193. 1 0.,0. 1.537,3.074,O.,.928525,3 1.,0.
305)
104
of the source
305 is given
by the
It is noted that the antenna fuselage
centerline.
Stations
250 and 305 are presented
The results
Both
at Station
calculated
reveal good agreement
and experimental
in Figures between
and scale model measurements.
105
250 is mounted
4" off the
results
for
26 and 27, respectively.
the theoretical
predictions
'top
CALCULATED ---
NOSE
!\
MEASURED
_
i
TAIL
BOTTOH ISCALEI
Figure
26.
EACH
DIVlSION-IODB)
Elevation plane pattern of a >,/4 monopole mounted 250 (off center) on top of a Boeing 737 aircraft.
106
at Station
lOP
--"-----
CALCULATED
BOTTON ISCRLE=
Figure
27.
ERCH
DIVISION-IODB)
Elevation plane pattern of a k/4 monopole 305 on top of a Boeing 737 aircraft.
107
mounted
at Station
The next antenna station computer data
location
considered
222 on the bottom of the fuselage simulated model
on the Boeing
737 aircraft,
just behind the nose.
for this case is shown
in Figure
28.
is
The The input
is as follows:
UN: I NCHES 3 FQ: 3.18 GHZ I ,3.18,1 . FG: BOEING 7.57 (STATION 66.,55.,765.,2.J2.52 F 0.,0.,0. SG: MONOPOLE 0.,-144.6 1 0.,0. 1.537,3.074,0 •,. 928525,3 1 .,0.
2.2.2)
Axial and circumferential station
222.
FC= FUSELAGE CHOPPED-OFF F,T 0. ,-186.97 PP: POLAR PLOT IN DB T 1,2.46,3 PD: ELEVATION PLANE 90.,90.,90. 0,360,1 F,6000. EX=
The source
slot antennas
geometry
input data
are also analyzed for these
for
two cases
are
given by the following:
SG: AXIAL SLOT 0.,-144.6 1 0.,0. 1.537,3 .,074, O.,. 1 .,0.
SG= C I RCUNFERENTI AL SLOT 0.,-144.6 1 928525,
The calculated
elevation
slot and circumferential patterns
in Figures
0,,0. 1.537,3.074,90.,. I .,0.
I
plane
patterns
slot at station
2q(a) through
good agreement. 108
928525,1
for the monopole,
222 are compared
(c), and they
are found
axial
with measured to be in very
RADOME
_'ANTENNA
Fi gure 28.
LOCATION
Computer simulated model for a },/4 monopole mounted at Station 222 on the bottom of the fuselage of a Boeing 737 aircraft.
109
------....
lOP
NOSE
CALCULATED MEASURED
TA ] L
BOTIOfl ISCALEs EACH DIV|SIONe|ODB)
(a)
Figure
29.
a
),/4 monople
case
Elevation plane patterns of an antenna mounted 222 on the bottom of a Boeing 737 aircraft.
110
at
Station
CALCULATED ....
MEASURED
lOP
i
NOSE
TAZL
BOTTOM ISCRLEs EACH DIVISION-IODB)
(b)
Figure
29.
an axial
(Continued).
111
slot
case
lOP
-
TAIL
NOSE
BOTTOH ISCALE:
(c)
Figure
29.
CALCULA'r ED MEASURED
EACH DIVISION-]ODB)
a circumferential
(Continued).
112
slot
case
Finally, the fuselage simulated
a _/4 monopole
is located at station
950 on the bottom
at the rear of the Boeing 737 aircraft.
model
for this case is shown in Figure
30.
of
The computer The input data
is
as follows:
UN: 3
INCHES
FO: 3.18 GHZ 1 •3.18,1 . FG: BOEING 737 (STATION 77. •74. •580. •200. F 0.•0.•0. SG: MONOPOLE 0,•300. 1
PG: HORIZONTN. STABILIZER 4,T -18.1,66.,443. -6.3,207.,561. -0.4•207.•620. -5.•66.•574. PG= HORIZONTN. STABILIZER 4•T -5.w"66.,574. -0.4,-207.,620. "6.3o-207.•561. -18.1,-66.•443. PP: POLAR PLOT IN DB T 1•2.38,3 PD: ELEVATION PLANE 90.,90.,90. 0,360,1 F,6000. EX=
950)
U,•U.
1.537,3.074•0 • •. 928525 •3 I .,0. PG: RIGHT WING 4•T 8.1,75.,-118. 33.9,536 •93 • 140. 40. •536.93,201 . 30.6,75.•.107. PG: LEFT WING 4•T 30.6•-75.•107. 40. ,-536.93,201 . 33.9 ,-536.93,140. 8.1 ,-75. •-I 18.
The elevation in very
plane
good _greement
radiation
pattern
with the measured
113
is computed
pattern
and found
as shown
to be
in Figure
31.
÷
/ ANTENNA
Figure
30.
LOCATION
Computer simulated model for a _/4 monopole mounted at Station 950 on the bottom of the fuselage of a Boeing 737 aircraft.
114
_CALCU LATED .... MEASURED
TAIL
NOSE
BOTTOM ISCRLEs EACH DIvISION-IODB}
Figure
31.
Elevation plane pattern of a 950 on the bottom of a Boeing
115
>,/4 monopole mounted 737 aircraft.
at
Station
Example
4:
Simulation
In this example antennas KC-135 32.
mounted
a monopole,
Aircraft
axial
both over and forward
aircraft.
The computer
Figures
of the KC-135
The line drawings simulated
models
slot and circumferential
Slot
of the wings
on a
of the KC-135 based
are studied
are shown
on the input data
in Figure are shown
33 and 34.
The input data for the monopole
mounted
over the wings
is as
follows: PG= VERTICAL STABILIZER 4,T 2.946,0.,49.492 14.076,0.,58.023 14.076 e-.5 _64.203 2.946,-.3,53.672 PG: NOSE 4,T 1.39,-1.36,-7.35 I .275,.-1.36,-9. I .37,0.,-9. 1.485,0.,-7.35 i_3: NOSE 4,T 1.483,0 .,-7,35 I .37,0 • .-9. I .27_, 1.36,-9. I .39, I .36,-7.35 PO= ELEVATION PLANE 90.,90.,90. 0,360,1 T, 1000. laP= PEN PLOT T 1,1.71,3 EX= PDs ROLL PLANE 0.,0.,90. 0,360,1 T, 1000. EXs PD= AZIHUTH PLANE, 90.,0.,90.2 0,360,1 T, IO00. EXI
UN= INCHES 3 FQ: 34.92 GHZ 1,34.92,1 • FG: KC-135 FUSELAGE GEOMETRY 3.3,3.,72.,8. F 0.,0.,18.81 SG: NONOPOLE OVER WING 0.4,18.81 I 0.,0. .140,. 230,g0.,. 0843,3 I .,0. PG: RIGHT WING 4,T -.5,3.,.12.31 -.5,28.5,36.41 -.5 w28.5,40.41 -.5,3.,24.61 F_: LEFT WING 4,T -.5,-3.,24.61 -.5,-20.5,40-41 -.5,-28.5,36.41 -.5w-3.,12.31 PG: VERTICAL STABILIZER 4,T 2.946,.5,55.672 14.076,._,64.205 14.076,0.,58.023 2.946,0. ,49.492
116
in
(a)
(b)
F =_L'T I,_
II
|
SIDE
////
VIEW
7? (c)
Figure
32.
VIEW
KC-135 aircraft,
117
TOP
VIEW
/7 (o)
(b)
FRONT
33.
VIEW
TOP
VIEW
VIEW
(c).
Figure
SIDE
Computer simulated model of a KC-135 is located over the wings.
118
aircraft.
The antenna
(o)
(b)
FRONT
34.
VIEW
VIEW
(¢)TOP
Figure
SIDE
Computer simulated is located forward
VIEW
model of a KC-135 of the wings.
119
aircraft.
The antenna
The radiation patterns of different
antenna configurations
on the
KC-135 maybe obtained simply by changing the source geometry command. The other source locations are specified
as follows:
SG: NONOPOLE FORWARDOF WINGS 0.,8.34 I 0.,0. • i 40.. 280.90. •. 0845 p3 1 .,0.
SGs AXIAL SLOT OVF.R WINGS 0.w18.81 I 0.,0. .140,. 280,0. p. 0843, I I .,0.
SG: AXIAL SLOT FORWARDOF WINGS 0.,8.34 I 0.,0. .140..280.0.p .0843,1 I .,0.
SG= CIRCUMFERENTIAL SLOT OVER WINGS 0,18.81 I 0.,0. .I 40,. 280, gO., .0845,1 I .,0.
SG= CIRCUMFERENTIAL SLOT FORWARDOF WINGS 0.,8.34 1 0.,0. • 140, • 280.90.,. I .,0.
0843, I
The elevation,
roll and azimuth KA-band
plane
patterns
waveguide
for a short
monopole,
a circumferential
and an axial
waveguide
mounted
forward
and over the wings
The computed
results
are found to be in very good agreement
are shown
KA-band
in Figures
35 to
43.
the measurements pattern
in the elevation
measurements
scale model were not available
(elevation
taken at NASA
for the azimuth
and roll planes. and roll plane
(Hampton, plane.
120
The precision
patterns)
Virginia).
with
using
Measured
the 1/25 data was
'fOP _ -
"-"_'_,,_
-""--'CALCULATED
.___
....
MEASURED
0011014
(o)
Antenna
mounted
forward
of
wings
TOP
I
NOSE
_
TRIL
BOTTOM ISCRLEs EREH OlVI$1ON-IOOB) (b)
Figure
35:
Antenna
mounted
Elevation plane pattern KC-135 aircraft.
121
over
wings
for a },/4 monopole
mounted
on a
TOP
--CALCULATED .... MEASURED
NOSE
TAIL
BOTTOR (a)
Antenna
mounted
forward
of
wings
TOP
NOSE
XRIL
BOTTOR ISCALEs EACH DIVISION=IODB) (b)
Figure
36.
Elevation waveguide
Antenna
mounted
over
vlngs
plane pattern for a circumferential mounted on a KC-135 aircraft.
122
KA-band
TOP
_CALCULATED .... MEASURED
NOSE
TRIL
BOTTOH (a)
Antenna
mounted
forward
of
wings
TOP
NOSE
;
TRIL
BOTTOM ISCRLEm EACH DIVIS|0N-|0DB) (b)
Figure
37.
Elevation mounted
Antenna
on
_unted
over
plane pattern for a KC-135 aircraft,
123
an
wings
axial
KA-band
waveguide
'lOP
CALCU LATED
/
LEF1
.,J ....
MEASUREO
W| NG
MING_
IOTTOH
(a)
Antenna
mounted
forward
of
wings
10P
LEFT WING
RIGHT W]NG
BOTTOM ISCALEs
(b)
Figure
38.
EACH
Antenna
Roll plane pattern aircraft.
DIVISION=IOD§)
mounted
over
wings
for a },/4 monopole
124
mounted
on a KC-135
TOP
CALCULATED
....
MEASURED
IIOTTO_ (a)
Antenna
mounted
forward
of
wlngs
10P
LEFT MING
RIGHT WING
BOT10M ISCRLE: (b)
Figure
39.
Roll plane mounted on
Antenna
ERCH DIVlSION-IODB) mounted
over
pattern for a KA-band a KC-135 aircraft.
125
wings
circumferential
waveguide
TOP
-....
CALCULATED MEASURED
RIGHT WING
LEFT WING
DOlION (a)
Antenna
mounted
forward
of
wings
TOP
LEFT NING
RIGHT "WING
DOTTOH ISCRLE: ERCH DIV]SION-IODB) (b)
Figure
40.
Antenna
Roll plane pattern a KC-135 aircraft.
mounted
for
126
overvlngs
a KA-band
axial
waveguide
mounted
on
.0se
----
E÷
--
Ee
LEFT MING
RIGHT WING
TRIL
(a)
Antenna
mounted
forward
of
.ose
wings -----
LEFT MING
E,II, Ee
RIGHT 14]NG
TR]L ISCI:ILEz EACH DIVIS]ON-[ODB)
(b)
Figure
41.
Antenna
mounted, over
Azimuth plane pattern aircraft.
127
wings
for a _/4 monopole
mounted
on a KC-135
NOSe
_
E¢ Eo
LEFT MINI;
FLIGHT MINI;
TRIL
(a)
Antenna
mounted
forward
of
llings
NOSE
E¢ Ee
LEFT MING
RIGHT ING
TRIL ISCRLEs
(b)
Figure
42.
Antenna
ERCN
OIVISION-IODB)
mounted
over
Wings
Azimuth plane pattern for a KA-band circumferential waveguide mounted on a KC-135 aircraft.
128
.osz
E_ Ee
_
LEFT MING
RIGHT "NING
TAIL
(e)
Antenne
mounted
forward
of
wings
NOSE
LEFT NING
I
,
i
RIGHT H]NG
TAlL ISCALEz EACH O]VXSION-IOOB) (b)
Figure
43.
Antenna
mounted
Azimuth plane pattern on a KC-135 aircraft.
for
129
over
wings
a KA-band
axial
waveguide
mounted
Example
5:
Simulation
A Lindberg crossed is studied shown data
of a Lindberg
Antenna
Mounted
slot antenna
mounted
on the fuselage
in this example.
in Figure 32.
The line drawing
The computer
is shown in Figure 44.
simulated
The input data
UNz INCHES 3
on a KC-135
of the KC-135
model
based
of a KC-135 aircraft
on the input
is as follows: PG= VERTICAL STABILIZER 4,T 2.946,0.,49.492 14.076.0.,-58.02-5 14.076,.,5,64.205 2.946.-.-5,5-5.672 PG= NOSE 4oT I .39,-1.36,-7.35 1.27-5,-1.36,-9. 1.37,0.,-9. 1.48-5,0 .,-7.3-5 PG: NOSE 4,T 1.48-5,0.,-7.35 I .37,0 • ,-9. 1.27-5,1.36,-9. 1.39,1.36,-7.3-5 PDZ ELEVATION PLANE
Fg. 6.25 g lZ 1,6.25,1. FGz KC-135 FUSELAGE GEOMETRY 3.3,3.,72.,8. F 0.,0.,18.81 SG" L INDBERG CROSSED-SLOT 0.,2.25 2 0.,0. .07375,1.475.0., .0845,1 I .,0. 0.,0. .07375,1.475,90., .0845,1 1.,90; PGz RIGHT WING 4,T -.5,3.,12.31 -.5,28.5,36.41 -.5,28.5,40.41 -.5,3.,24.61 PG: LEFT WING 4,T -.5.-3.,24.61 -.5,-28.5,40.41 -.5,-28.5,36.41 -.5,-3.,12.31 I_: VERTICAL STABILIZER 4,T 2.946,.5,55.672 14.076,._,64.20-5 14.076.0.,58.02-5 2.946,0.,49.492
90.,90.,90. 0,360,1 T, 1000. PP" PEN PLOT T I ,I .62-5,3 EXs PO= ROLL PLANE 0.,0.,90.2 0,360,1 T, 1000. EXz = AZIMUTH PLANE 90.,0.,90. 0,360,1 T, 1000. EXs PD= 4-5°CONICAL 90.,0.,45. 0,360.1 T, IO00. EX= 130
CUT
was
( b)
FRONT
(0)
SIDE
(c)
TOP
VIEW
VIEW
LINDBERG ANTENNA (STATION 470)
J
Figure
44.
Computer KC-135.
simulated
VIEW
model for Lindberg
131
antenna
mounted
on a
Various calculated patterns along with the measured results taken from reference [17] are presented in Figures 45 to 48. agreement is obtained.
Again, good
The gain level in each case is adjusted to
compare with measurements. The Ee pattern corresponds to the vertical component, E¢ to the horizontal
componentand Ecp to the circularly
polarized field.
132
lOP
"-----" ....
CALCULATED MEASURED
1RIL
NOSE
BOTTON [SCRLEs ERCH DIV]SION-IODB) TOP
(o)
E4,
NOSE ._._
TA|L
BOTTOH ISCRLEs ERCH DIVISION-)0DB)
(b)
Figure
45.
Elevation plane KC-135 aircraft.
pattern
133
for
Lindberg
Ee
antenna
mounted
on
a
TOP
NOSE
TRIL
BOTTOM ISCRLE=
ERCH
(c)
Figure
45.
DIVISION-IODB)
Ecp
(Continued).
134
'lOP --
CALCULATE D
- MEASURED LEFT |
_ I
I
f _
_
_
_ _
! R|GHT
MING _
MING
BOTTON ISCflLE:
ERCH DIVIS]ON-IODB) TOP
(o)
E¢
""..
LEFT! /
! _/
__._
/
",_'f
_ ---I_
I
'_ I RIGHT
MING _
MJNG
BOTTON ISCRLE8 ERCfl DIV]SION.]ODB)
(b)
Figure
46.
Roll plane pattern KC-135 aircraft.
for
135
Lindberg
antenna
Ee
mounted
on
a
TOP
LEFT WING
RIGHT WING
BOTTOM (SCRLE:
ERGH DIVlSION-IODB)
(c)
Figure
46.
Ecp
(Continued).
136
NOSE _CALCUL&TIrD MEASURED
I
LEFT
R|GHT
MING
_.
-
_
NING
1RIL ISCRLEs
ERCH OIVISION-10DB)
(o)
E_
LEFT XING
R1GMT "XING
TAlL ISCRLEs ERCH DIVISION-10DB)
(b)
Figure
47.
Azimuth KC-135
plane aircraft.
pattern
for
137
Lindberg
Ee
antenna
mounted
on
a
NOSE
LEFT WING
RIGHT WING
TRIL ISCRLE:
ERCH
DIVISION-IODB)
(c)
Figure
47.
Ecp
(Continued).
138
NOSE --'----
LEFT
CALCULATED
RIGHT
TAlL ISCRLEs
EACH DIVISION-|ODB)
(o1 _"
mR_ _v_
LEFT NING
RIGHT WING
TAIL ISCALEs EACH DIVISION-)ODB)
(b)
Figure
48:
Azimuth mounted
conical pattern 0p=45 o) on a KC-135 aircraft.
139
for
Ee
Lindbert
antenna
NOSE
LEFT WING
RIGHT WING
TRIL ISCRLEz
ERCH
(c)
Figure
48.
(Continued).
140
DIVISION-IODB)
Ecp
Example
6:
In
Simulation
this
example
of
antenna the
402B aircraft
just
Cessna
402B is
in
input
data
is
shown
402B
a monopole
Cessna
shown
Cessna
in
above Figure
Figure
49, 50.
C_: INCHES 3 FQ- FIVE GIGR_ER_ 1,5.,1. t_- CESSNA 402B 8.2,26 •,285. ,152. F 0 •,0. ,0 • :
_Uk_J_
is
mounted
cockpit.
The
and the
on the line
computer
The input
data
drawing
model is
-_ _V
p:
of
the
on the
(L_T
SIIE)
,-68. ,0 • ,-68. ,65. ,-68. ,85. ,-68.,85. ,-68. ,-40.
g 01kO
based
of
as follows:
t_'.RJF.4_ENGINE -36.8 -36.8 -36.8 -21.8 -21.8
fuselage
._a ,
_lklP.
,_
O
_G: LEFT ENGINE eIOP) 4,F -21.8,68. ,-40. -21.8,106. ,-40. -21.8,106. ,85. -21.8,68. ,85. PG:RIE4ff ENGINE eIOP) 4,F -21.8 ,-68 •,-40 • -21.8 ,-68. ,85. -21.8 ,-106. ,85. -21.8 ,-106 •,-40. PG: LEFT ENGINE (LEFE SIEE) 6,E -36.8,106. ,65. -36.8,106. ,85. -21.8,106. ,85. -21.8,106. ,-40. -36.8,106. ,-40. -36.8,106. ,0 •
0.,-10. 1 0.,0. •414,.828,0 .,.25,3 I.,0. I_G: LEFT WING (INNER B%RT) 4,T -41.8,26.0,0 • -36.8,68. ,0. -36.8,68. ,65. -41.8,26 •,65. _: RIGHT WING (_ ]/%RT) 4,T -41.8 ,-26. ,65. -36.8 ,-68.,65. -36.8 ,-68 •,0 • -41.8 ,-26.0,0. I:(]:LEFE I_GINE (RIGHT SIDE) 6,F -36.8,68.,0. -36.8,68. ,'40. -21.8,68. ,-40. -21.8,68.,85. -36.8,68. ,85. -36.8,68. ,65.
141
a
R;I L_ jIJn. TA_K H2GE #I 4,F -26.8,213 .,0. -14 .8,219. ,-32. -14 .8,21% •,82 • -26.8,213 • ,50 • I:G_ RF...ST _EL _ PLA_ #1 4,r -26 .8 ,-213 • ,0 • -26 .8 ,-213 .,S0. -14.8 ,-219. ,82. -14.8 ,-219. ,-32. .q;s LEFT FUEL TANK HJtTE #2 4,W -14.8,119.,-32. -8.8,23 5.,0. -0.8,235.,50. -14 .8,21 9. ,82 • l:Gs R]G_ Fuzr., TANK PLRIE 12 4,F -14.8 r219. ,-32. -14 .8 ,-21%. ,82. -8.8 ,--235.,50. -8.8 ,-235.,0. PDs RGLL RL_NE 0.,0.,90. 0,360,1 F, 4200. PPs T 1,2.5,3
IK3# E]Y.,I_E_ DG_E (RIGHT SEE) 6,1' -36.8,-106.,65. -36 .8 ,-106.,0. -36 .8 ,-106.,-40. -21.8 ,-I06 .,-40 • -21.8 ,-106.,85 • -36.8 ,-106. ,05 • I_I L_I_" EI_E (I_CXT) 4,F -it .8,60.,-40. -36 .8,68.,-40. -36 .8,106 .,-40. -21.8,106 .,-40. l_a RIGHT E_INE (I_CNT) 4,F -21.8 ,-68. ,-40. -21.8 ,-106 .,-40. -3b.8,-1U6.,-40. -36.8 ,-68 • ,-40. I_| LEF_ W2G (OU_I_ _T) 4,r -36 .8,106 .,0. -2S .8,213 .,0. -26.8,213 • ,50. -36.8,106. ,65. H;'.RIGST WING (OU_R _T) 4,F -36.8 ,-106 .,0• -36.8 ,-106.,65. -26 .8,-It3.,50. -26 .8 ,-213.,0.
The calculated
roll plane
found to be in good agreement Experimental
results
were
radiation
pattern
with the measured obtained
in Figure
51 is
pattern.
from NASA
using the I/7 scale model at a range of 50 feet.
142
shown
(Hampton,
Virginia),
ANTENNA"
LOCATION
(a)
SIDE
(b)
Figure
49.
Cessna
VIEW
FRONT
402B.
143
VIEW
I
m
÷
(a)
(b)
Figure
50.
Model
for Cessna
TOP
¥ lEg
FRONT
VIEW
402B with engines
144
and fuel tanks.
----'---
COM
....
EXPERIMENTAL
PUTEO
TOP
LEFT
RIGHT H!NG
i.
RAmU
I
BOTTOH ISCRLEs ERCH DIV|SION=1ODB)
Figure
51.
Roll
plane
pattern
for
145
Cessna
402B
model.
Example
7:
Simulation
Consider Beechcraft
of Beechcraft
a L/4 monopole
Baron aircraft
based on the input data
Baron
mounted
as shown
is shown
forward
of the cockpit
in Figure
in Figure
52.
53.
of a
The computer The input data
model is as
fol lows :
UNz]2a3:1_ 3 FOz FIVE GIG_ 1,5.,1. FGx _.EQ:tC2_ 15.5,23.2,206.5 ¥ 0.,0.,0.
4,r -2.6,84.5,-62. 11.4,84.5,-62. 8.4,50.5,-62. -5.6,50.5,-62. PGz RI(_]T WING 4,T -10.,-23.5,60. 10. ,-227., 27. 10.,-227.,-10. -10.,-23.5,-20. _z RIGHT D_G_ (LEFT SIDE) 6,F -5.6,-50.5,-62. -5.6,-50.5,-8.5 -8.6,-50.5,-8.5 -8.6,-50.5,20. 8.4,-50.5,20. 8.4,-50.5,-62. I_s RIG_ I_IGI1_Ig ('lOP) 4,F 8.4,-50.5,-62. 8.4,-50.5,20. 11.4,-84.5,20. II.4,-84.5,-62. I_s RI(g:_ ENGINE (RIGHT SIDE) 6,F -5.6,-84.5,20. -5.6,-84.5,-7. -2.6,-84.5,-7. -2.6,-84.5,-62. II.4,-84.5,-62. 11.4,-84.5,20.
]_.RQ¢ w117.5
0.,-7"I. I 0.,0. .414,.828,0.,.25,3 1.,0. PGz LEFT WING 4tT -10.,23.5,-20. l&., 227. ,-10: 10.,227.,27: -10.,23.5,60I_ LEFT I_GI_ (RIGHT SIIE) 6,¥ -5.6,50.5,-62. 8.4,50.5 ,-62. 8.4,50.5,20. -8.6,50.5,20. -8.6,50.5,-8.5 -5.6,50.5,-8.5 IGz LEIT I_]GIb_ CIDP) 4,F 8.4,50.5,-62. 11.4,84.5,-62. 11.4,84.5,20. 8.4,50:5,20.
146
1_;: LEFT I_GI_E 6,F -5.6,84.5,20. 11.4,84.5,20. 11.4,84.5,-62. -2.6,84.5,-62. -2.6,84.5,-7. -5.6,84.5,-7.
_
The conical
plane
roll
SIIE)
radiation
I:G- RIGHT ENGI_ 4,F -2.6,-84.5,-62. -5.6,-50.5,-62. 8.4,-50.5,-62. 11.4,-84.5,-62. PD: ROLL PLANE 0.,0.,80. 0,360,1 F,4200. PP: T 1,2.5,3 EX:
pattern
147
is
shown
in
Figure
54.
ANT[NNA LOCATION
(a)
TOP
VIEW
L (b)
Figure
52.
Beechcraft
FRONT
VlEIV
Baron with Antenna
148
in forward
location.
I
I
|
I
I
I ANTENNA
LOCATION
(a)
(b)
Figure
53.
Beechcraft
TOP
VIEW
FRONT
Baron model
149
VIEW
with engine
housings.
TOP
-'----
COMPUTED EXPER I MENTAL
LEFT NING
RIGHT ING
BOTTOM ISCRLEs ERCH DIVIS|ON-IODB)
Figure
54.
Roll conical pattern shown in Figure 53.
(Op=80 o)
150
for
Beechcraft
Baron
model
Next, front the Four
of
let the
rotation
engines. of
different
propellers as shown considered as
us consider It
the
is
chosen
Figure here.
effect
55. The
because
(i.e., to
simulate For
input
of
necessary
propellers
positions are
in
the
O°,
to
rotating only the
four
the
are
45 ° , 90 °,
the
for
rotating
check
they
simplicity, data
the
propellers scattering
close
135 °) motion the
left
different
in
to of
of
due to
the
the
the
antenna. stationary
the
propellers
propeller propellers
is are
follows:
_o t_LU_; AT U
3,F 2.9,-67.5,-66. -37.1,-70.,-67. -37.1,-65.,-65.
_G: PROPElLeR (_DI')AT 90 _ 3,F 2.9,-67.5 ,-66. 0.4,-187.5,-65. 5.4,-107.5,-67. PG: PROPELLOR (BO'I"3I_) AT 90 ° 3,F 2.9,-67.5,-66. 0.4,-27.5,-65. 5.4,-27.5,-67.
PG: PROPELLER (_DP) AT 45 ° 3,F 2.9,-67.5,-66. 29.414 ;-97.554,-65. 32.954,-94.014,-67. PG: PRDPEU/)R (BO_E_) AT 45 ° 3,F 2.9,-67.5,-66. -27.154,-40.986,-67. -24.384,-37.446 ,-65.
PG: PROPEUX_ (_OP) AT 135 ° 3,F 2.9,-67.5,-66. 32.954,-40.986,-65. 29.414,-37.446,-67. PG: PROPELLOR (_I) AT 135 ° 3,F 2.9,-67.5,-66. -23.614 ,-97.554,-67. -27.154,-94.014 ,-65.
_: k'HIJl-_Ld.L_ 3,F 2.9,-67.5,-66. 42.9,-70.,-65. 42.9,-65.,-67. PG: PROPELLOR
(BOFIDM) AT
0°
151
I
+
ANT[Nk4 LOCAT,ON
(a)
TOP
VIEW
&NT[klN& °
o
"'-
/
LOC&T
ION
I
I a J_
h
(b)
Figure
55.
Beechcraft side.
Baron
FRONT
model
152
with
VIEW
rotating
propellers
on
one
The calculated different The previous variation
conical
propeller roll
of
positions
plane
patterns. the
roll are
pattern
in
The width radiation
plane shown
Figure of
radiation
the
pattern
propellers.
153
in
Figures
57 is pattern
due to
patterns 56(a)
of
indicates
rotation
the
through
a combination line
the
for
of
the the
the
four (d). four
TOP
LEFT HINO
RIGHT WING
BOTTON ISCRLEs ERCH O|VlSION-IOOB)
Figure
56(a).
Roll conical propeller at
pattern for the 0 ° (vertical).
154
Beechcraft
Baron
with
TOP
LEFT WING
' RIGHT WING /
I
BOTTOH ISCRLEs ERCH OIVlSlON-IODB)
Figure
56(b).
Roll conical propeller at
pattern 45 ° .
155
for
the
Beechcraft
Baron
with
TOP
LEFT NING
RIGHT WING
BOTTOH ISCALEz EACH OIVISION-[OD8)
Figure
56(c).
Roll conical pattern at 90 ° (horizontal).
156
for
Beechcraft
Baron
with
propeller
TOP
RIGHT ,WING
LEFT
80TTOH ISCRLEs ERCH OlVlSION-IODB)
Figure
56(d).
Roll conical propeller at
pattern 135 ° .
157
for
the
Beechcraft
Baron
with
"TOP
RIGHT M|NG
LEFT HING'
BOTTOH ISCALEs EACfl 91VlSION-]ODB)
Figure
57,
Variation Baron due
in to
the the
roll conical rotation of
158
pattern for the the propellers,
Beechcraft
Example
8:
In of
Simulation
this
a Cessna
example,
of
and the
shape
in
UN: 3 C'rt. | IiLwe
of
Figure
Figure
the of
the
58,
59.
the
antenna
150 aircraft
plates
due to
are
data
is
I U_ I ,k,.
86.,0. 1 0.,0. .414,.828,0.p.25,3 1 .,0. PG: NOSE PLATE 4,T -17.35,32.53,-17.52 -27.35,82.4,-15.18 -27.35,82.4,15 • 18 -17.35 ,.32.53,17.52
Figure it
is
pattern
60. of
the is
Although correct
elevation the
plane
magnitude
spatial
was taken
the
position
simulated
in of
the
on the
input
antenna
composite
the
Cessna
wings
the
the
by the
simulate
of
on the
nose
and
150 is
data
is
shown shown
in
i:'G= FUSELAGE PLATE 4,T -tB.67p-25.2;1.4:93 10.,-152.,3.17 10. _-152. ,-3 .17 -18.67 ,-2.5.2,-14.93 laD= ELEVATION PLANE AS REFERED TO THIS 0.,0.,90. 0,360,1 F,4200 PP; PEN PLOT T 1,1.925,3 EX"
1 pS.pl . FG: CESSNA 150 WING 3.5,25. w250.1,250. F 0.,0._,0. FC: SQUARE OFF WING TIPS T,T 196.25,,-196.25 SG: HONOPOLE MOUNTED ON WING
resulting
based
forward
as follows:
__ ! __AI.I_'D'Ir'7 Vll=Mlilt,,m_14J,
The
mounted
to
drawing
model
INCHES I_ |
are
attached
The line computer
is
approach
The wings
aircraft.
and the
150 Aircraft
A different
wings.
flat
The input
Cessna
a monopole
Cessna
and two
fuselage
the
150 aircraft.
modeling
ellipsoid
of
pattern of
frequency,
good. 159
the
for ripple and the
this is
model not
general
is
shown
in
quite
perfect,
shape
of
the
MODEL
NA LOCAT ION
(e)
TOP
VIEW
.OCATION
|
(b)
Figure
58.
Cessna
FRONT
150.
160
ANTENNA
VIEN
÷
(a) Top view.
• /'1
ANTENNA
LOCATION
f
. //s
t /
// S/
(b) Side view.
Figure
59.
Cessna 150 model. simulation.
Dashed
161
lines
are not part of the computer
....
[X pIrR IIdI[NTAL.
TOP
I'AIL
NOSE
BOTTON ISCALEI EACH OlVlSlON-]OOO)
Figure
60.
Elevation
plane pattern
162
for a Cessna
150 aircraft.
Example
9:
Simulation
Consider aircraft A composite
in
Figure
ellipsoid
structure
of
62.
that
Note
fuselage.
F-16
a TACAN antenna
as shown
quarter
of
the
mounted
aircraft.
model
of
on the
of
of
data the
the
F-16
at
is
_1
K o _
"_'4 ,
6...o
ANN .
,"v_
are
The input
a F-16
is
used
as
by General data
PG:
fighter of
to
is
0.96
in
o
p
_..ov
Dynamics
6,T 8.2046,22.4421 ,-151 . 2.141 8,36.'5,-61 • -4.0866 ,'50 .g42 ,-8.6 -'5.40'54,'54. ,8.743 -5.40'54,54., 1'58 .g'5 8.2046,22.4421 , 1'58.9'5 PG:CURVATURE SIMULATED PLATE #2 ON POS. '5,T 8.2046,22.4421,1'58.g'5 -5.40'54 ,'54., 158 .g'5 .2805,'54 • ,209.084 -7.6944,54. ,290.084 '5 .g156 ,22 .4421,290.084
163
SIDE
a
as follows:
CURVATURE SIMULATE PLATE #3 ON POS. SIDE
0.5,19.2,-150. 2.1418,36.5,-61. 8.2046,22.4421
ON POS. SIDE
Figure
using
e
F 0.,0.,0. FC: T,T 300. ,-185 • F@:FREQUENCY I ,0-.96,1 . SG: SOURCE GEOMETRY 0.,13.2.5 1 0.,0. 0.,0.,0.,3.07'58,3 1 .,0. PG:CURVATURE SIMULATED PLATE ll
the
a truncated
'_KN w
GHzo
simulate
illustrated
simulated
UN: IN INCHES 3 FG:F16A FUSELAGE GEOMETRY AT STATION 250 6,1
of
a frequency
model
was obtained F-16.
top
12 plates
The computer
radome
The measured
Aircraft
61 and operated
and a total
the
scale
Fighter
,-61.
PG:wING ON POS. SIDE 4pF -.5.40.54,54. p8.743 -S.4054,180 .,114.47 -.5.4054,180., 158.95 -.5.4054,54., 158.95 PG:HORIZONTAL STABILIZER ON POS. SiDE 4,F -5.4054,54.,219.7958 -5.4054,109.101,266.021 -.5.4054,10g. 101,290.084 -.5.4054,54. ,290.084 PG:VERTICAL STABILIZER ON NEG. SIDE 4,,T 20.,0.p160. 120. ,0.,261. 120.,-3.4,298. 20.,"6.8,2)4. PG:VERTICAL STABILIZER ON POS. SIDE 4,T 20.,6.8,234. 120.,3.4,298. 120.,0.,261 . 20.,0.,160. PG:CURVATURE SIMULATED PLATE I1 ON NEG. SIDE 6,T 8.204¢ ,-22.4421 • 1.58.95 -5.4054,'54., 158.95 "5.4054,'54.,8.743 -4 • 0866,'50.942 ,-8.6 2.141 8,-36 ..5,-61 • 8.2046,-22.4421 ,'_51 . PG:CURVATURE SIMULATED PLATE 12 ON NEG. SIDE 5•T 5.91 56 ,-22.4421,290.084 -7.6944,-54 .,290.084 -6.2805,-54 .,209.084 -5.4054,'54., 158.95 8.2046 ,-22.4421 • 158.95 PG:CURVATURE SIMULATED PLATE /3 ON NEG. SIDE 3,T 8.2046 ,-22.4421 ,--61. 2.1418,-36 ..5,-61 . 0.5,-19.2,-150. PG:WING ON NEG. SIDE 4,F "5.4054,-54., 158.95 -5 •40.54,-i 80., 158.95 -5.40.54,-! 80.w114.47 -5.4054,'54. ,8.743
164
PG:HORIZONTAL ,STABILIZER 4,F
ON NEG. SIDE
PD:ELEVATION 90.,90.,90.
PLANE CUT
-5.4054,-54., 290.084 -5.4054 ,-109.101,290.084 -5.4054 ,-109.101,266.031 -5.4054,-.54. ,219.7958 PP, POLAR PLOT IN DB T 1,2.81,3 PO:AZINUTH PLANE CUT 90.,0.,10. 0,360.,1
0,360., 1 T, 50000. EX: EXECUTE PI : 9 PD- ROLL PLANE CUT O. ,0.,90. 0,180.,1 TpPO000. TO:
T,50000. EX: EXECUTE PD:AZIMUTH 90.,0.,20. 0,360.,1 T,50000. EX: EXECUTE PD:AZIMUTH 90. ,0. ,30. 0,360.,I T,50000. EX: EXECUTE I l 1 PD:AZIMUTH 90.,0., 11.5. 0o360.,1 T°50000. " EX: EXECUTE PD:AZIMUTH 90.,0.,120.
F,F,F T,T T,T,T,T,T,T,T,T 1,9,1 2,6,1 1,5,1 1,3,2 !,4,1 1,4, ! i ,4,i 1,4,1 2,3,1 I,3,2 DD: 5 1,6,1,3 1,6,4,1 1,6,4,4 4,1,1,6 4,4,1,6 RJ_: 1
PLAJqE CUT
PLANE CUT
PLANE CUT
PLANE
CUT
0,360., I T, 50000, EX: EXECUTE
1,4 EX= EXECUTE
To show the complete azimuthal 82.
conical
patterns
volumetric
radiation
are calculated
In each case, both the principal
considered. in Figure
The elevation
as shown
and cross
plane and roll plane
83 and 84, respectively.
165
patterns,
the various
in Figures
polarizations patterns
All the above
63 through are
are also shown
calculated
results
compare
favorably
cockpit
section simulation
expect nose
good agreement
between
the calculated
in our model, and measured
is part of the radiation
the ripple above the aircraft
likely created
It is noted that
is not complete
region since the cockpit
addition, most
with the measurements.
by the cockpit
model.
166
which
since
one cannot results
path.
in the elevation is not simulated
the
in the
In
pattern in this
are
TACAN
ANTENNA
49 31 FT
I
[8]
32.83
6IDE
VIEW
FT
pI
-
31 FT W/O
MISSILES
"--_!
I
o 0
[¢|
Figure
61.
F-16
fighter
aircraft.
167
o
o
TOP
VIEW
[ [o)
(b|
FRONT
SIDE
VIEW
[©]
Figure
62.
Computer
VIEW
simulated
model
168
TOP
VIEW
of a F-16 fighter
aircraft.
ORIGLNAL
PAGE
IS
OE POOR qUALITY U
* , ....
L|F1 lING
CALCULATED MEASURED
AIGM1 "WING
(SCALE:
TRIL
|o)
EACH DIVISZON=
4DB}
Ee me_
Le,FT lING'
HIGH1 "U]N&
Tall
(b)
Figure
63.
E÷
Azimuthal conical pattern _Op=lO o) of a _,/4 monopole mounted on top of a F-16 f ghter aircraft.
169
__
CALCULATED
---
(SCALE: --
-- MEASURED
EACH DIVISION:
4DB)
IlL
(ali
Ee
'NING
IN|L
(b) E÷
Figure
64.
Azimuthal conical pattern (op=20 °) of a >,/4 monopole mounted on top of a F-16 fighter aircraft.
170
R
._
_¢_'-_'_
LEtrl HIN5
I
I
I
! .'1
2 cA,cuLA=Eo
_
_
.::_,r
_
_
__-_-
MEASURED
liIGH1 H|N5
(SCALE:
EACH DIVISION:
4DB)
|II|L
(o)
Ee
mE
LEFt J/MS'
RIGH1 WING
1IlL
(b)
Figure
65.
E÷
Azimuthal conical pattern (0p=30 o) of a X/4 monopole mounted on top of a F-16 fighter aircraft.
171
n
_ ....
[SCALE:
(o)
CALCULATED MEASURED
EACH DIVISION=
4DB}
Ee llX
_'"
!:I=1
N]NG
(b)
Figure
66.
E÷
Azimuthal conical pattern (Op=40o) of a _/4 monopole mounted on top of a F-16 fighter aircraft.
172
I
'
LEF1
CALCULATED MEASURED
-
nl_1
IIII IgG '
_MING
__
(SCALE:
EACH DIVISION:
4081
IlIIL
(o)
Ee
_'_
LI_T
__
m|GN1
IIIWG '
IdlWC
lllZL
(b)
Figure
67.
E÷
Azimuthal conical pattern (9p=45 o) of a LI4 monopole mounted on top of a F-16 fighter aircraft.
173
N
CALCULATED
,
lil_ '_
--------
MEASURED
11_'
(SCALE:
EACH DIVISION=
4DB)
11tiL
(o)
Ee
'lING
11111.
(b) E÷
Figure
68.
Azimuthal conical pattern (Op=50 o) of a _/4 monopole mounted on top of a F-16 fighter aircraft.
174
n
-....
"
- CALCULATED MEASURED
UlBG
CALE: EACH DZVZSZON= 4DB ) lm]L
(o)
Ee
(b)
Figure
69.
E+
Azimuthalon conical (0 =55o_ ircraft. of a >,/4monopole mounted top of apattern F-16 fighter
175
CALCULATED MEASURED
....
RIGHT K|NG
(6CALE:
(a)
EACH DIVIBION=
G)
Ee IllS[
,IIIGNT
Till
(b)
Figure
72.
E+
Azimuthal conical pattern (ep=70 °) of a >,/4 monopole mounted on top of a F-16 fighter aircraft.
178
i
.1_._
hf:_,
-
CALCULATED
....
MEASURED
mixing
St'ALE:
EACH DIVISION:
4013)
TliiL
(a)
Ee U
_EFT lmG
AIGW1 'Wing
TR|L
(b)
Figure
71.
E÷
Azimuthal conical pattern (0p=65 o) of a _/4 monopole mounted on top of a Fo16 fighter aircraft.
177
m
___
___,
CALCULA'rEo
.l SCALE: EACH DIVISIIN=
4_B)
N
,mi_T WIIIG
N!
(b)
Figure
70.
E÷
Azimuthal conical pattern (Op=60 o) of a X/4 monopole mounted on top of a F-16 fighter aircraft.
176
IE
CALCULATED
....
(SCALE:
MEASURED
EACH DIVISION=
4DB)
1IlL
(a)
Ee mE
L|F1 NIU_
RIGN1 'UlN_
1alL
(b)
Figure
73.
E÷
Azimuthal conical pattern (0p:75 o) of a >,14 monopole mounted on top of a F-16 fighter aircraft.
179
_i_
I/__;Io
_,
_.._.,_
(SCALE:
EACH DIVISION=
4DB)
llllL
(O)
E0
kf'.,Z
i
I
I
lil|L
(b)
Figure
74.
E÷
Azimuthalon conical pattern (o =80O)aircraft. of a X/4 monopole mounted top of a F-16 fighter
180
• ....
LEFT MIIG
CALCULATED MEASURED
.R|GHT M/NG
(SCALE:
(a)
EAI_i DIVISION:
4DB)
Ee
LEFT NING'
RIGHT "WING
1ilL
(b)
Figure
75.
E 4,
Azimuthal conical pattern (9p=85 o) of a X/4 monopole mounted on top of a F-16 fighter aircraft.
181
IIIII
-- CALCULATED
,_
lif:_,
----
-
M[ASURED
"'_:I.Y
(6CALE:
EACH DIVISION=
41)B)
WIlL
(o)
IEe
ll16wl "UlUC
LI_F1 UlN_
TIlL
(b)
Figure
76.
E÷
Azimuthal conical pattern (Op=90 o) of a X/4 monopole mounted on top of a F-16 fighter aircraft.
182
llnl
• CALCULATED MEASURED
....
L|;T NIMG
_
A|GNT "NlM_
(SCALE:
EACH DIVISION:
4OB)
'Will
|a)
Ee
L!;_ MIN& '
nlr_1 WINC
lmlL
(b)
Figure
77.
E#
Azimuthal conical pattern (Op=95 °) of a >,/4 monopole mounted on top of a F-16 Tighter aircraft.
183
U
- CALCULATED MEASURED
....
_II_
"°"'
WING
(SCALE:
IRIL
(a)
EACH DIVISION=
4DB)
Ee mR
LfeY NING
mlGoql 'WING
Ill&
(b)
Figure
78.
E+
Azimuthal conical pattern (Op=lO0 o) of a ),/4monopole mounted on top of a F-16 fighter aircraft.
184
CALCULATED MEASURED
....
LEFt lING
RIGNT 'lllO
(SCALE:
EACH DIVISION=
4DE)
mlL
(o)
Ee gO,JR
LEF_ WING'
R|GN1 uluG
|RIL
(b)
Figure
79.
E 4,
Azimuthal conical pattern (9p=105 o) of a },/4 monopole mounted on top of a F-16 fighter aircraft
185
N
....
CALCULATED MEASURED
RIGHT NING
IIIIL
(BCALE:
(o)
EACH DIVISION=
4DB)
Ee
LEF1 mlNG
MI|W1 UlIIG
mlL
(b)
Figure
80.
E÷
Azimuthal conical pattern (op=110 o) of a >,/4 monopole mounted on top of a F-16 fighter aircraft.
186
I
CALCULATED
....
[SCALE:
MEASURED
EACH DIVISION:
41113)
IIIIL
ImSE /
L[;1 BING
_
,
,
A|GNT "NIMG
IRIL
(b) E+
Figure
81.
Azimuthal conical pattern (0p=115 o) of a X/4 monopole mounted on top of a F-16 fighter aircraft
187
,.
---
.. CALCULATED MEASURED
il:l
illiL
Iol
E
"'
_°
'
llilL
(b)
Figure
82.
E_
Azimuthal conical pattern (Op=120 o) of a X/4 monopole mounted on top of a F-16 fighter alrcraft.
188
' -----
CALC ULATED -" M[ASURED
10P
NOSE
....
[
....
iM)L
I
BOTlO_ ISCRLEs
Figure
83.
ERCH
DIVISION-
Elevation plane pattern a F-16 fighter.
189
qDB)
of a X/4 monopole
mounted
on top of
CALCULATED ....
MEASURED
TP
LEFT
RIGHT WING
IOIIOH ISCRL[:
Figure
84.
Roll F-16
ERCH DIVISION-
qDi)
plane pattern of a _/4 monopole fighter aircraft.
190
mounted
on top of a
Example 10:
Simulation of F-4 Fighter Aircraft
Consider a _/4 monopole mountedon the bottom fuselage of an F-4 aircraft,
which is loaded with armament, and operated at a frequency of
.375 MHz. The measureddata was obtained at the RADCNewport antenna range.
The line drawings and the computer model of the F-4 aircraft
illustrated
are
in Figure 85 and 86, respectively.
Note that since the
antenna is mounted on the belly of an aircraft,
the coordinates are
defined so as to associate with the bottom part of the aircraft. Consequently, the geometry of the F-4 in our computer model, as well as the pattern coordinate systems, are turned upside down. In fact,
for
the Bp=75 ° pattern computed here, the actual pattern angle from the vertical
is 180°
- 75° or 105° .
The input
n uem
iG6,T -2. -2. -2. -2. -2. -2.
3 rQ: _ 375 ltlZ 1,.375,1, tG: F-4 5.,20.,300.,250. F 0.,0.,0. SG." MCI_PO_ O. ,-200. I 0.,0. .414,. 828,0. ,7.87,3 1.,0. I=G: LEf'/WING 6,T -2.,18.,-133. -2.,50.,-133. -2. ,50.,-70. -2. ,230. ,119. -2.,230.,167. -2. ,18. ,136.
data is as follows:
ILIG_
WII_
,-18. ,136. ,-230. ,167. ,-230., 119. ,-50. ,-70. ,-50. ,-133. ,-18./,-].33.
4,T -2.,18.,-133. -2.,50.,-133. -4. ,50. ,-133. -4.,18.,-133. tG:RIGBT _IGINE 4,T -4.,-18.,-133. -4. ,-50.,-133. -2. ,-50. ,-133. -2.,-18.,-133.
191
INTAKE
l_s )R.I_ I_)LE )P_ 4,F 20.,-72. ,-].17• 0.,-72. ,-I17 • 0.,-72. ,-45. 20.,-72.,-45I:(;:UDT FuD, TA_ 4,P 36.,127.,148o 0 •, 127., 148 o 0.,12"f.,-77. 36., 127 .,-77. _G: P.IG_T FdEL TN_ 4,F 36.,-127.,-77. 0. ,-127 _,-77. 0.,-1Z?.,148. 36.,-127.,148. PPz K]LAR I_OT T 1,2.9,3 PD:AZ_ (3E]NICAL 90.,0. ,75. 0;360,1 P,5000.
6wT 4.,9.e-50. 15. ,13. ,_-50. 25. ,6.,-50; 25. ,--5o,-50. 15. ,-13.t-50. 4.,-9. ,-50. )L_G=T._ ]_)_ ]:HTR_E 4,F -4.,50.,-133. -52.,50.,-133. -52. w18.,-133. -4. ,18. ,-133. L:G: RIGHT ENGINE 4,P -4.,-18.,-133. -52.,-18.,-133. -52. ,-50.,-133. -4. ,-50.-,-133. IG: LEFf MISSILE 4,F 20.,72.,-45. 0.,72.,-45. 0 •,72. ,-117. 20. ,72. ,-117.
The azimuthal Figure thetwo
87.
conical
Although
patterns
pattern
there exists
is compared
with measured
some discrepancy,
are in good agreement.
192
data
the general
in
shape
of
(o)
(b)
FRONT
SIDE
VIEW
(c)
Figure
85.
VIEW
F-4 (Phantom)
fighter
193
aircraft.
TOP
VIEW
(a)
FRONT
(b)
Figure
86,
Computer
simulated
VIEW
BOTTOM
model
194
VIEW
of a F-4 Phantom
fighter
aircraft,
....
MEASURED
NOSE
TRIL (SCRLEs
Figure
87.
ERCH OIVISION-IOOO)
Azimuthal conical pattern (Op=105 °) of a },/4monopole mounted on the belly of a F-4 fighter aircraft.
195
Example 11: Simulation of an A-IO Aircraft Consider four monopoles mounted on the belly of an A-IO aircraft shown in Figure 88. The mutual neglected coupling
coupling
Each monopole is spaced a half wavelength apart. between
in the pattern
the monopoles
calculations.
effect on the radiators
method
[4].
Figure
89.
The computer
is significant The excitation
is obtained
model
The input data
based
using
on the input
and cannot including
EFPBCT
I_ATE
PLATE
196
IN(ItDED
be
the
the thin-wire
moment
data
in
is shown
is as follows:
U_: INQBE_ 3 FQ: 17.576 Q_Z 1,17.576,1 FG- A-10 FUS_ 0.117,0.425,8.05,2.62 F 0.,0.,0. SG: MONOPOLE ARRAY WlTH U)UI_ING 0.,-1.29 4 .336,180. 0.,0.,O.,0.168,3 .272,14. .336,0. 0.,0.,0.,0.168,3 .272,14. .168,270. 0.,0.,0:,0.168,3 1.0,-3.0 .504,270. 0.,0.,0:,0.168,3 .272,14. PG: LEFT WING INN_ 4,T 0.05,. 425,.07 0.05,1.86,.07 0.05,1.86,2. 0.05,. 425,2. PG: RIGHT WING _ 4,T 0.05,-.425,2. 0.05,-1.86,2. 0.05,-I.86,. 07 0.05,-.425, .fly
as
IN (XIRRE_
VAL_
ORIGLNAL PAGE IS OF POOR QUALII_
4,F 0.05,1.86,.07 -.,i5,5.6,.49 -.0.45,5.6,1.77 0.05,1.86,2. I:G: ]R.I(WT WJ3_ GYl'J_ ,liwF 0.05,-1.B6,2. -.45,-5.6,1.77 -.45,-5.6,.49 0.05,-1.86,.07 IG" _ FUg[,-TN'_ 4,F 0.05,1.58,-.6 .30,1.58,-.6 .30,1.58,2. 0.05,1.58,2. I:G :IJ3Yl' _ 4,1' .30,1.58,=.6 .59,1.86,-.6 .59,1.86,2. .30,1.58,2. PG" RIG:G' lrdEL TN_ 4,F .30,-1;58,2. .59,-1.86,2. .59,-1.86,-.6 .30,-1.58,'.6 IG: ILIGI_ ¥1J_ 4,F 0.05,-1.58,2. .30,-1.58,2. .30,-1.58,-.6 0.05,-1.58,-.6
result
_
PLml'E_
pp=
T 1,2.5,3 lgX=
TN_
The azimuthal measured
im: IPG,(N 1 4,F .4,0.53,1.61 .05,0.53,1.61 .05,0.53,.56 .4,0.53,.33 ]L:G" PG,(lq 2 4,F .4,-.53,.33 .05,-.53,.56 .05,-.53,1.61 .4 ,-.53,1.61 I:G: PG,(_ 3 4,F .4,1.05,1.61 .05,1.05,1.61 .05,1.05,.56 .4,1.05,.3 PG: P21,OH 4 4,F .4:-1.05;.3 .05,-1.05,.56 .05,-1.05,1.61 .4,-1.05,1.61 PD: M,I]4Ym (INZCkL 90.,0.,75. 0;360,1 T,6000.
conical
data obtained
patern
(_p=105 °) is compared
at the RADC Newport
shows good engineering
agreement.
197
with the
site in Figure
90.
The
(o)
(b)
FRONT
BIDE
VZEW
VIEW
C
(c)
Figure
88.
A-IO aircraft.
198
TOP
VZEW
(a)
FRONT
VlEff
I
(b)
Figure
89.
Computer
BOTTON
simulated
VIEW
model of an A-IO
199
aircraft.
....
ME &SURED
NOSE
LEFT N]NG
RIGHT WING
TR]L ISCRLEz
Figure
90.
ERCfl
DIVISION-tODB)
Azimuthal conical pattern (Bp=105:) of four monopoles mounted on the belly of a A-IO aircraft
200
Example
line
12:
Simulation
of C-141
Consider
a monopole
drawings
and the computer
91 and 92, respectively.
(IN- FEET 2 FG: C141 FUSELAGE 7.37,8.37,90.,46.05 F
mounted
Aircraft
on the top of a C-141
aircraft.
model of the C-141 are shown
The input data
GEOMETRY
0.,0.,0. FQ: 2.52 GHZ 1.,2.52,1. SG • SOURCE GEOMETRY 0.,0. "I ,,L
0.,0. 0 _2,0.5,0.,0.09,3 lo,0o
PG- WING ON POSITIVE SIDE 5,T 6.0,7.37 ,-7 .4 .04 6.0,78.6,27 .86 6.0,78.6,36 .6 6.0,30.7,24 .1 6.0,7.37,23 PG: WING ON NEGATIVE SIDE 5,T 6.0,-7.37,23.1 6.0,-30.7,24.6 6.0,-78.6,36.86 6.0,-78.6,27.04 6.0,-7.37,-7.4 PG: VERTICAL STABILIZER POSITIVE 4,T 7.5,1.6465,88.11 24.58,1.,92.81 24.58.0.,77.45 7.5,0.,62.82 NEGATIVE PG: VERTICAL STABILIZER 4,T 7.5,0.,62.82 24.58,0.,77.45 24.58,-I.,92.81 7.5 ,-I .6465,88.11
201
The
in Figures
is as follows:
PGs T-TAIL POSITIVE SIDE 4,F 24.58,1.,92.81 24.58.25.3,98.22 24.58,25.3,92.05 24.58,0.,77.45 PG: T-TAIL NEGATIVE SIDE 4,F 24.58,0.,77.45 24.58,-25.3,92.05 -')4 .., ,_"-')'_.....3,98 ,, ....._') 24.58.-1.,92.81 PP: POLAR PLOT IN DB T 1,1.42,3 PD: AZIMUTH PLANE PATTERN 90.,0.,90. 0,360,1 F,1000. EX:
SIDE
SIDE
(o)
(b)
FRONT
91.
C-141
VIEW
VIEW
(c)
Figure
SIDE
aircraft.
202
TOP
VIEW
(o)
(b)
FRONT
SIDE
VIEW
VIEW
/-/
/
//
/ANTENNA
(c)
Figure
92.
Computer
simulated
TOP
model of a C-141
203
VIEW
aircraft.
Various
azimuthal
conical
70 °, 80 ° , 90° , 100 ° , see Figure are computed
and compared
and 94, respectively. Dynamics aircraft. model
(San Diego,
patterns 10(c))
with measured
The experimental California)
The calculated
using
results
measurements.
204
(10° , 20° , 30 ° , 40 °, 50 ° , 60 ° , and the elevation results
plane
as shown
in Figures
work was performed a 1/10 scale model
compare
very favorably
pattern 93
at General of a C-141
with the scale
NOSE
MEASURED
CALCULATED LEFT NING
:IGIHG
TAIL i,., )
_
. ,no
NOSE
LEFT NING
RIGHT ING
TAIL ISC.ALE:
EACH
OlVISION=IOOB)
(b) 8p. 20 °
Figure
93.
Azimuthal conical C-141 aircraft.
patterns of a I/4 monopole
205
mounted
on a
NOSE CALCULATED MEASURED
LEFT NING
RIG MING
1'ALL
(c)
ep = 30 °
NOSE
LEFT MING
RMIGHTNG
TAIL ISCALEs
EACH
( d)
Figure
93.
(Continued).
206
DIVISION=IODB)
8p
• 40 °
NOSE
LEFT NING
----.--
CALCULATED
------
MEASURED
RIGHTNG
TRIL (e)
ep
= 50 °
NOSE
IGHT _ING
LEFT MING
TRIL ISCRLEs (f)
Figure
93.
(Continued).
207
ERCH ep.
DIV]S|ON-IODB) 60 °
NOSE CALCULATED "----
LEFT MING
MEASURED
RIGHT WING
TAIL NOSE (g)
Op
=70
LEFT
°
_
_"
/_'_Jf_"_
_
WING
TAIL ISCRLE=
EACH
(h)
Figure
93.
(Continued).
208
DIVISION-1ODB}
8p -80 °
_
| .TGH
QiNG
,
NOSE CALCULATED
kEASUnED
LEFT NING
RIGHT NING
TRIL NOSE
( i ) 8p • 90 °
.,,
