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Instructions on building antennas
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THIS PACKAGE IS A USEFUL ANTENNA ANALYSIS PROGRAM FOR THE RADIO
AMATEUR, PROFESSIONAL, TECHNICIAN AND STUDENT INTERESTED IN ANTENNA DESIGN.
IT IS STILL UNDER DEVELOPMENT AND YOUR COMMENTS WILL BE USEFUL
TO THE AUTHORS. TO USE THESE PROGRAMS YOU MUST:
1. Add GWBASIC to the disk.
2. You should compile the programs you wish to use or else they are too
slow although still useful.
3. The manual describes a menu system but this feature is not included
in this package. Programs can be loaded separately an run.
The manual is lacking in a few line diagrams that are included
with the original printed and bound version.
Any comments can be addressed to:
A. J. Ferraro
RM 225 EEE
University Park, Pa.
16802
INTRODUCTION
Concepts and ideas can be more easily understood when one
can feel and visualize what is being discussed. This is ever
more so in the teaching of electromagnetic theory where there is
so much abstraction. The instructor has the arduous task of
formulating his ideas and presenting it to the students who have
no other alternative but to try to understand as much as they
can. An application of the electromagnetic theory is antenna
engineering. This is an area where many discussions are centered
around the "invisible". Describing an antenna pattern is not an
easy job and when there are many cases to study, drawing many
patterns is no fun either. This is where this courseware
package comes in.
This package was designed in the Electrical Engineering
Department at Pennsylvania State University. It is aimed at
both the students and faculty. To the undergraduate students,
the approach to this package is to treat it as an antenna
engineering laboratory. Instead of hooking up wires and
equipment, students can carry out experiments on the computer.
This saves time and effort since changing several parameters can
be done quickly and results are immediately displayed. Graduate
students who are preparing for the candidacy examinations can
use it as a review or to get some information in a limited time. The
faculty can use it to try new ideas and also to formulate exam
questions.
Basically, this courseware covers courses EE361, EE411,
EE432, EE438 and EE538 offered by the Electrical Engineering
Department at Penn State. Presently, only topics which are
related to antenna engineering are covered. The package can be
divided roughly into six areas. These are Transmission line
problems, wire antennas, arrays, broadband antenna, aperture
antenna and antenna synthesis.
Transmission line problems can be used by students taking
courses EE361, EE432 and EE438. It involves simple matching
methods. Wire antennas includes the straight wire dipole, the
folded dipole and the Yagi-Uda antenna. This module can be used
to study the radiation patterns, self impedance of a single
element and the mutual impedance between two elements. This
module is particularly relevant to students in EE361 and EE438.
The third module is Arrays. Mutual impedance between
several elements are studied. Array characteristics such as the
driving point impedance, efficiency and directivity can be found
for various linear array configuration. Feed line designs for
the array are also included. The radiation pattern of
rectangular and circular planar arrays can be computed for
different array configuration. Students taking EE432, EE438 and EE
538 should find this module useful.
The next module is Broadband antennas. The design of the
Log periodic dipole array is made easy using this module. Other
topics include linear, rectangular and circular aperture, the
parabolic antenna and the horn antenna. These antenna are
discussed in EE438 and EE538.
The study of antenna engineering is incomplete without
knowing antenna synthesis. In normal antenna design, the
radiation pattern and array factor are calculated after the
antenna configuration is established. However, in antenna
synthesis, the desired pattern are first specified. This is then
followed by a procedure to find the best antenna configuration
that meets the pattern requirement. The classes of synthesis
method which are covered are the Woodward-Lawson line source and
array factor, the Chebychev synthesis and the Taylor line source
method. This last module is fully covered in the graduate course
EE538.
03
ANTENNA ENGlNEERlNG COURSEWARE
by
AHMAD FAlZAL MOHD. ZAlN and DR. ANTHONY J. FERRARO
ELECTRICAL ENGlNEERlNG DEPARTMENT
PENNSYLVANlA STATE UNIVERSITY
The authors have made every conceivable effort to ensure the correctness and
accuracy of the programs. However, no implied warranty of guarantee of any
kind
is made with respect to the accuracy, completeness and effectiveness of
these
programs.
Under no circumstances will the authors be liable for incidental or
otherwise
consequential damages in connection with the furnishing of, or the
performance
of, or as a result of the use of any of these programs.
USING THE COURSEWARE
1. Switch on the computer.
2. You will be presented with an option to type in the date and
time. Press return twice if you do not wish to do so.
3. A disclaimer notice will then be displayed. Please read it
carefully.
4. After striking any key, a menu screen would the come up.
This is similar to the map in Fig. 1.
5. Select your choice by pressing the appropriate function
keys labelled Fl to F10 on the left side of the keyboard.
6. Pressing F10 will return you to the previous menu.
GETTING HARDCOPIES
If you would like to get a hardcopy of the plots or the screen,
just press the keys <SHIFT> and <PrtSc> together. Make sure the
graphics printer is turned on!
SELF IMPEDANCE OF A DIPOLE
The self impedance of a dipole antenna depends on its
length and radius of wire used. This program will calculate the
self impedance of a straight wire dipole given its length and
radius using the approximate induced emf method (refer to Jordan
and Balmain). The radiation resistance is referred to the loop
current. The resistance referred to the base is R(loop)/sin H.
Thus for antenna length which are a multiple of half-wavelength, the
input resistance, R(base), would theoretically be infinite. Thus we
need to use a different method.
For those cases, you are referred to a program called
MININEC in the book 'MICROCOMPUTER TOOLS FOR COMMUNICATIONS
ENGINEERING by Shing Ted Li et al. It is published by Artech House.
The program uses the moment method to compute the current
distributions, impedance and patterns of any antenna composed of
wires arbitrary oriented in free space or over perfect ground.
PROGRAM NAME : SELFIMP
VARIABLE LIST:
H : Length of dipole in terms of lambda
A : Radius of dipole in terms of lambda
RIN : Real part of self-impedance
XIN : Imaginary part of self-impedance
PROCEDURE:
Choose F2 (WIRE ANTENNAS) from main menu. Then choose Fl
(DIPOLE (STRAIGHT WIRE)). Finally choose F2 (Self-impedance of
dipole).
EXPERlMENT
1. For a half wavelength dipole with radius 0.0035 lambda, find
the self impedance.
2. Try the same experiment with a smaller radius, say .00014
lambda.
3. For both the antennas above, what is the resonant length of
each? What can you conclude? Which antenna is better for
broadband use, a thicker or a thinner one?
4. What is the self impedance of a monopole of half the height
of the dipole?
MUTUAL IMPEDANCE BETWEEN TWO DlPOLES
OF ANY LENGTH AND SEPARATION
The mutual impedance of two dipoles changes with distance
of separation between them. This program allows one to change
both the distance of separation and length of two identical
dipoles and computes the mutual impedance. This is useful for
finding the driving point impedance of a linear array of
dipoles.
PROGRAM NAME : MUTUAL
VARIABLE LIST:
H : Length of dipole in terms of lambda
D : Separation between the dipoles in terms of lambda
R21 : Real part of mutual impedance
X21 : Imaginary part of mutual dipole
PROCEDURE:
Choose F2 (WIRE ANTENNAS) from main menu. Then choose Fl
(DIPOLE STRAIGHT WIRE)). Finally choose F3 (Mutual-impedance of
2 dipole).
EXPERIMENT
1. Find the mutual impedance between two half wavelength
dipoles separated by .25, .5 and 1 lambda.
2. What happens if the separation is 0 lambda?
3. Plot a graph of the mutual resistance and reactance with
respect to separation for dipoles of half wavelength in a side
by side configuration. Do the same for a collinear
configuration. Which one gave more reactance? Why?
4. For a side by side configuration, plot the mutual resistance
and impedance with respect to separation for dipoles of length
0.4, 0.45 and 0.55 lambda. What happens to the mutual impedances
as the length is increased?
DRIVING POINT IMPEDANCE
This program will compute the driving point impedance of an
array of parallel side-by-side evenly spaced half-wavelength
dipoles. It will also calculate the power radiated, directivity
and efficiency of the array. Feedline design using quarter
wavelength line is also included.
PROGRAM NAME : DRIVPT
VARIABLE LIST:
N : Number of elements
LAMBDA : Element spacing
I(J) : Excitation currents
A(J) : Phase of excitation currents
ZDR(ROW) : Real part of driving point impedance
ZDX(ROW) : Imaginary part of driving point impedance
WATT(ROW) : Power radiated by each element
WATTRAD : Total power radiated by array
DIRECTDB : Directivity in dB
Z0 : Characteristic impedance of main line
Z0(I) : Characteristic impedance of feed-lines
RIN(I) : Input impedance of feed-lines
FREQ : Working frequency
ECD : Efficiency of array
PROCEDURE :
Choose F3 (ARRAYS) from main menu. Then choose Fl (LINEAR
ARRAY). Finally choose Fl (Driving-point impedance).
EXPERIMENT
1. Find the driving point impedance of a 2-element array of
parallel side-by-side lambda-by-two dipoles spaced half
wavelength apart and fed with currents of equal amplitude and
zero phase shift between them.
2. Try with a phase shift of 90 and 180 degrees. Which has
better directivity?
3. Change the second current to twice the first with zero phase
shift. What happens?
4. Design a 3-element array of three half-wavelength dipoles
separated .65 lambda apart. The currents are I1=1, I2=2 and
I3=1. All have zero phase shift. The transmitter is rated at
10 kW at 500 MHz and is to be matched to a 75 ohm coaxial main
feed line.
NOTE: The feedlines of quarter wavelength long are all
connected at one point. The quarter wavelength lines can be
extended by half wavelength lines if they are too short due to
physical constraint.
RADIATION PATTERN PLOT OF DIPOLE ANTENNA
This program will plot the radiation pattern of a dipole of
any length.
PROGRAM NAME : DIPOLE
VARIABLE LIST:
L : Length of dipole in lambda
PROCEDURE:
Choose F2 (WIRE ANTENNAS) from main menu. Then choose Fl
(DIPOLE (STRAIGHT WlRE)). Finally choose Fl (Pattern of any
length).
EXPERIMENT
1. For a half-wavelength dipole, plot the radiation pattern.
What is the HPBW and directivity?
2. Repeat 1) with dipoles of wavelengths 0.25, 0.75, 1, 1.5 and
2 lambda. When do you get multiple lobes?
NOTE: The dipole is oriented vertically in the polar plot.
TRANSMISSION LINE
This program calculates the input impedance of a lossless
transmission line, given the characteristic impedance, the load
impedance and its length. The reflection coefficient and SWR is
also computed.
PROGRAM NAME : TXNLINE
VARIABLE LIST:
FREQ : Working frequency
Z0 : Characteristic impedance
RL : Real part of load impedance
XL : Imaginary part of load impedance
L : Length of line in meters
REAL : Real part of input impedance
IMAG : Imaginary part of input impedance
GAMMA : Magnitude of reflection coefficient
ANGAMMA : Angle of reflection coefficient
S : SWR
PROCEDURE :
Choose Fl (TRANSMISSION LINE PROBLEM) from main menu. Then
choose Fl (Input impedance, load , etc.)
EXPERIMENTS
1. For an open circuit line of .2 m at 300 MHz, what is the
input impedance? What is the input impedance for a line of .6 m
at the same frequency? What about a .25 m line? Can you plot a
9raph of the input impedance versus length at 300 MHz?
2. Try the same experiment for a short circuit line.
3. When are the input impedance of an open circuit and a short
circuit line the same?
4. What does a quarter wavelength do to the load?
5. What is the input impedance of a half wavelength line? Try
the experiment using an open circuit, a short circuit and with a
load of 30+j80 ohms at 300 MHz.
6. What is the reflection coefficient and SWR of an open and
short circuit line? What about a matched load?
7. What happens to the reflection coefficient for a resistive
load which is greater than the characteristic impedance? What
about a smaller load?
8. Given a transmission line of half a meter, with a load of
25+j75 ohm, what is the input impedance of the line at 300 MHz?
9. What is the reflection coefficient and SWR?
10. What happens to the input impedance when the length is
changed to a quarter meter?
SINGLE STUB MATCHING
This program will compute the length of the short circuit
stub and its distance from the load needed for matching. Two
solutions are given. The program requires the operating
frequency, the characteristic impedance and the load as input.
PROGRAM NAME : STUBMATC
VARIABLE LIST:
FREQ : Working frequency
Z0 : Characteristic impedance of line
RL : Real part of load impedance
XL : Imaginary part of load impedance
Sl,S2 : Stub lengths
Dl,D2 : Stub distance from load
B : Stub reactance
PROCEDURE:
Choose Fl (TRANSMISSION LINE PROBLEM) from main menu. Then
choose F2 (Single stub matching).
EXPERIMENT
1. A 50 ohm transmission line is connected to a load of
impedance 25-j75 ohm. Find the position and length of a short
circuited stub needed to match the line.
2. Using the transmission line program, what is the SWR before
and after matching?
3. Try the experiment with a load impedance of 50 ohm.
4. Can you match a load of 100+j100 ohm to a 50 ohm line?
LOG PERIODIC DIPOLE ARRAY
The Log-periodic dipole array (LPDA) is a very broadband
array. This program computes the number of elements, lengths
and spacings for a certain frequency bandwidth determined by the
desired maximum and minimum frequencies that the LPDA is to
operate over.
PROGRAM NAME : LPDA
VARIABLE LIST:
FMIN : Minimum frequency (MHz)
FMAX : Maximum frequency (MHz)
TAU : Scale factor
SIGMA : Spacing factor
ALPHA : Vertex angle
N : Number of elements
L(I) : Length of elements
X : Length of array
PROCEDURE:
Choose F4 (BROADBAND ANTENNAS) from the main menu. Then choose
Fl (Log-periodic dipole array).
EXPERIMENT
1. Design a LPDA to operate from 54-216 MHz.
For details on the geometry and definition of the parameters
sigma, tau and alpha, see Antenna Theory and Design by Stutzman
and Thiele, John Wiley and Sons, 1981, page 287.
YAGI-UDA ARRAY
The Yagi-Uda array is a very directive and high gain array.
In this program, the three-element Yagi is studied. The
reflector and driver is of half-wavelength. The length of the
director can be varied by changing its reactance. The distance
between the reflector and driver and the director and driver is
set with the provision of changing the director spacing during
the program. This permits the front-back ratio to be determined
for various setting of director lengths and spacings.
PROGRAM NAME : YAGI
VARIABLE LIST:
SR : Spacing between driver and reflector
SD : Spacing between driver and director
XZ(3,3) : Director reactance
ZR(0) : Director resistance
ZDR : Driving point impedance of YAGI (real part)
ZDX : Driving point impedance of YAGI (imaginary part)
MAGEFTOB : Front/Back ratio
D : F/B Directivity
DBACK : B/F Directivity
PROCEDURE:
Choose F2 (WIRE ANTENNAS) from main menu. Then choose F3 (Yagi
Uda antenna).
EXPERIMENT
1. Find the optimum F/B ratio for a three-element Yagi with a
spacing of 0.1 lambda between the elements. What is the driving
point impedance and directivity at that value? (Tabulate the
F/B ratio for different director reactance).
2. For a fixed length of elements and a distance of 0.1 lambda
between the reflector and driver, find the distance between
the director and driver which gives the optimum F/B ratio. What
is the driving point impedance and directivity of the array? (Tabulate the
F/B ratio for different director spacing).
3. When does the reflector functions as a director?
4. What is the advantage of using a Yagi array?
UNIFORM LINEAR PHASED ARRAY
Linear array will plot out the array factor for an
equispaced, isotropic sources excited with equal magnitude of
current with progressive phase shift.
PROGRAM NAME: LINPHASE
VARIABLE LIST:
ALP : Progressive phase shift in degrees
D : Element spacing in lambda
N : Number of elements
THE0 : Main beam direction
PROCEDURE:
From the main menu choose F3 (ARRAYS). Then choose F2 (ARRAY
FACTOR) from the next menu. Finally choose Fl (Uniform linear
phased array).
EXPERIMENT
1. Plot the array factor of a 2-element array with .5 lambda
spacing and zero phase shift. Where is the main beam?
2. Now increase the phase shift by 180 degrees. (The phase
shift can be incremented or decremented by 10 degrees using the
up or down arrow cursor keys. However, you are recommended to
quit and rerun program if the change in phase shift required is
large). Where is the main beam? Is the directivity the same as
before?
3. Tabulate the HPBW and directivity for an array with 5, 10,
20, 50 and 100 elements.
4. Do the same as above, but this time steering the beam by 45,
90 and 180 degrees? Does the HPBW and directivity stay the
same? If not, why?
5. What is the advantage of increasing the number of elements?
What is the better trade-off, HPBW or directivity?
NOTE: The isotropic elements are placed horizontally in the
polar plot.
LINEAR ARRAY (BEAM STEERING)
Linear array will plot out the array factor for an
equispaced, isotropic sources excited with equal magnitude of
current with progressive phase shift. The user can specify the
main beam direction and it will compute the required phase
shifts required and also plot the array factor.
PROGRAM NAME: LINSCAN
VARIABLE LIST:
ALP : Progressive phase shift in degrees
D : Element spacing in lambda
N : Number of elements
THE0 : Main beam direction
PROCEDURE:
From the main menu choose F3 (ARRAYS). Then choose F2 (ARRAY
FACTOR) from the next menu. Finally choose F2 (Linear array
(beam steering)).
EXPERlMENT
1. plot the array factor of a 5-element array with .5 lambda
spacing and main beam directed at 0. What is the phase shift
required?
2. Now steer the beam to ten degree. What is the required
phase shift? ls the directivity the same as before?
3. Tabulate the HPBW and directivity for an array with 5, 10,
20, 50 and 100 elements.
4. Do the same as above, but this time steering the beam by 45,
90 and 180 degrees? Does the HPBW and directivity stay the
same? If not, why?
5. What is the advantage of increasing the number of of elements? What is
the better trade-off, HPBW or directivity?
NOTE: The isotropic elements are placed horizontally in the
polar plot.
PLANAR RECTANGULAR ARRAY
Given the direction of the main beam required (both theta and
phi), this program will compute the progressive phase shift for a
rectangular planar array. The user can also specify the phase
shifts, and it will calculate the main beam direction. It will also
plot the array factor in both the xz-plane and yz-plane.
PROGRAM NAME : RECTPLAN
VARIABLE LIST:
THE0 :Main beam direction in THETA
PHI0 :Main beam direction in PHI
M :Number of elements in x-direction
N :Number of elements in y-direction
DX :Element spacing in x-direction
DY :Element spacing in y-direction
ALPX :Progressive phase shift in x-direction
ALPY :Progressive phase shift in y-direction
PROCEDURE:
From the main menu, choose F3 (ARRAYS). Then choose F2 (ARRAY
FACTOR) from that menu. Finally choose F3 (Planar rectangular
array).
EXPERIMENT
1. Design a 10 x 8 (10 elements in x-direction and 8 elements
in y-direction) element uniform planar array so that the main
beam maximum is oriented along theta=10 and phi=90. For a spacing of
dx=dy= 1/8 between the elements, find the
a) progressive phase shift between the elements in the x and y
direction.
b) directivity of the array.
c) half-power beamwidths (in the perpendicular planes) of the
array.
2. Repeat 1) such that theta=80 and phi=90.
Why does the directivity and half-power beamwidth change?
PLANAR CIRCULAR ARRAY
Given the direction of the main beam required, this program
will compute the phase excitation for a uniform circular planar
array. It will also plot the array factor in both the xz-plane
and yz-plane.
PROGRAM NAME : CIRCULAR
VARIABLE LIST:
THE0 :Main beam direction in THETA
PHI0 :Main beam direction in PHI
N :Number of elements
A :Radius of array
ALPN :Phase excitation
PROCEDURE:
From the main menu, choose F3 (ARRAYS). Then choose F2 (ARRAY
FACTOR) from that menu. Finally choose F4 (Circular Planar
array).
EXPERIMENT
1. For a 10 element circular array with main beam in the theta=0
and phi=90, find the phase excitation required. The radius of the
array is 1.591 lambda. Plot the array factor in both the xz and
yz plane. Calculate the directivity.
2. Using the same number of elements and main beam direction,
increase the radius to 2,2.5, 5, 10 lambda. What is the
directivity?
THE WOODWARD-LAWSON SYNTHESIS METHOD
The Woodward-Lawson method allows one to input a desired
pattern. It will then plot the pattern and the current
distribution. WOODLS is used to synthesize the line source and
WOODAF is used in array synthesis.
PROGRAM NAME : WOODLS and WOODAF
VARIABLE LIST:
WOODLS WOODAF
L : Line source length NE : Number of elements
W(I : Sampling point D : Element spacing
A(I) : Desired pattern A(I) :Desired pattern
I(I) : Current magnitude I(I) :Current magnitude
PHI(I):Phase shift
PROCEDURE:
Choose F6 (ANTENNA SYNTHESIS) from the main menu. The choose F3
(Woodward-Lawson line source) or F4 (Woodward-Lawson linear
array).
EXPERIMENT
USING F3 OPTION
1. The desired pattern is unity from w=-0.5 to 0.5 and zero
elsewhere. It is to be synthesized with a ten-wavelength line
source using the Woodward-Lawson method.
a) Plot the pattern in linear rectangular form.
b) Plot the current distribution.
Repeat the synthesis using a) f(theta)=0.5 at w=-0.5 and w=0.5 and b)
f(theta)=0 at w=-0.5 and w=0.5.
Which choice is closer to the desired pattern? Can you explain
why?
USING F4 OPTION
2. The sector pattern above with f(theta)=0.5 at w=0.5 is to be synthesized
with a 10 element, half-wavelength spaced array. Determine the element
position, current excitation and phase. Plot the synthesized pattern.
Repeat the above using increasing number of elements (say 15,
20, 50, 100, etc.). What is a reasonable number of elements you
would use to achieve the desired pattern?
3. A collinear array of 18 half-wave dipole antennas is to be
used to synthesize a sector pattern with a main beam sector over
the region 70 <theta< 110, that is f(theta)=1 over this region and zero
elsewhere.
a) For 0.65 lambda spacings determine the input currents
required for Woodward-Lawson synthesis of the complete pattern.
Account for the element factor.
b) Plot the total array pattern.
4. Repeat experiment 3 for a cosecant desired pattern where
f(theta ) is 1 for 80 < theta < 90, cos 80/cos(theta) for 0 < theta <
80,
and zero elsewhere.
DOLPH-CHEBYCHEV SYNTHESIS METHOD
The Dolph-Chebychev method give a compromise between narrow
beamwidth and low side lobe levels. This program will generate
the excitation currents and plot the array factor for a broadside,
equispaced linear array.
PROGRAM NAME : CHEBY
VARIABLE LIST:
NE : Number of elements
D : Element spacing
RR : Side-lobe level (-dB)
HP : Half-power beamwidth
A(N) : Excitation currents
PROCEDURE:
Choose F6 (ANTENNA SYNTHESIS) from the main menu. Then choose
F2 (Dolph-Chebychev array).
EXPERlMENT
1. For a five-element, broadside, -20 dB sidelobe, half-
wavelength spaced Dolph-Chebychev array,
a) Obtain the pattern plot
b) Verify the sidelobe level and beamwidth from your pattern.
2. Design a Dolph-Chebychev broadside array of five, half
wavelength spaced elements for a -30 dB sidelobes.
a) Obtain the current distribution.
b) Compute the directivity.
3. Design a broadside Dolph-Chebychev array with six, 0.6
lambda spaced elements for -25 dB sidelobes.
a) Obtain the element currents.
b) Plot the pattern.
TAYLOR LINE SOURCE SYNTHESIS
The Taylor line source synthesis method allows for narrow
main beam with the first few sidelobes having nearly equal level
and decreasing far-out sidelobes.
PROGRAM NAME : TAYLOR
VARIABLE LIST :
NB : Number of equal side-lobes
RR : Side-lobe level (-dB)
L : Aperture length
A(J) : Sampling currents
W(J) : Sampling points
HPWI : Half-power beamwidth w.r.t wi
HP : Half-power beamwidth
PROCEDURE:
Choose F6 (ANTENNA SYNTHESIS) from the main menu. The choose Fl
(Taylor line source).
EXPERIMENT
1. Design an eight-wavelength Taylor line source (nbar=7) with
-30 dB sidelobes.
a) Obtain and tabulate the sample values and locations.
b) Plot the pattern in rectangular logarithmic form.
UNIFORM RECTANGULAR APERTURE
Given the width of the aperture in both the x and y
direction, this program will compute the half-power beamwidths
in the xz and yz-plane. The directivity is also calculated. The programs
the
plots the radiation patterns in both the principal planes.
PROGRAM NAME : RECTAPER
VARIABLE LIST:
LX : Width in x-direction in terms of lambda
LY : Width in y-direction in terms of lambda
HPX : Half-power beamwidth in xz-plane
HPY : Half-power beamwidth in yz-plane
D : Directivity
PROCEDURE:
From the main menu, choose F5 (APERTURE ANTENNAS). Then choose
Fl (Uniform rectangular aperture).
EXPERIMENT
1. Find the half-power beamwidths for a uniform rectangular
aperture which has Lx=20 lambda and Ly=10 lambda. Plot the
pattern. What is its directivity?
2. Do the same thing for an aperture with Lx=3 lambda and Ly=2
lambda.
REFERENCES
1. Antenna Theory and Design by Warren L. Stutzman and Gary A.
Thiele
- John Wiley & Sons, 1981
2. Antenna Theory by Constantine A. Balanis
- Harper & Row, 1982
3. Antenna Design using Personal Computers by Pozar
- Artech House
4. Microcomputer Tools for Communication Engineering by
Shing Ted Li et. al.
- Artech House, 1983
EVALUATION FORM
Contrary to popular beliefs, this evaluation form will be
fully scrutinized. So please fill it with care. This will not
only help us to understand your needs, but it will also allow us
to modify and further improve the courseware.
IF YOU=STUDENT THEN FILL SECTION A
ELSE GOTO SECTION B
SECTION A
1. Circle one : FRESHMAN SOPHOMORE JUNIOR SENIOR
MASTERS PRE-CANDIDACY POST-CANDIDACY
2. Circle the courses that you have taken :
Write the grade you obtained beside the courses you circled.
EE361 EE411 EE432 EE438 EE538
3. Circle the courses that you are currently registered :
EE361 EE411 EE432 EE438 EE538
4. Circle the courses you plan to register in future :
EE361 EE411 EE432 EE438 EE538
If you had not used this courseware, would you still had
plan to registered for these courses?
EE361 Y/N EE411 Y/N EE432 Y/N EE438 Y/N EE538 Y/N
5. Would you choose Antenna Engineering as a career? Y/N
SECTION B
1. Circle the programs that you used :
TXNLINE STUBMATC DIPOLE SELFIMP MUTUAL YAGI
DRIVPT LINPHASE LINSCAN RECTPLAN CIRCULAR LPDA
RECTAPER TAYLOR CHEBY WOODLS WOODAF
2. On the scale of : 1 - POOR
2 - FAIR
3 - GOOD
4 - VERY GOOD
5 - EXCELLENT
how would you rate each program? Write your rating beside
each of the programs below.
TXNLINE STUBMATC DIPOLE SELFIMP MUTUAL YAGI
DRIVPT LINPHASE LINSCAN RECTPLAN CIRCULAR LPDA
RECTAPER TAYLOR CHEBY WOODLS WOODAF
3. Circle your ratings below:
a. Increased understanding of
Antenna Engineering 1 2 3 4 5
b. Easiness of understanding
concepts 1 2 3 4 5
c. Visualization of the
concepts presented l 2 3 4 5
d. Expectation 1 2 3 4 5
e. Learnt something new 1 2 3 4 5
f. Overall performance 1 2 3 4 5
g. Documentation 1 2 3 4 5
h. Ease of use 1 2 3 4 5
i. Value 1 2 3 4 5
4. Would you recommend others to use it? Y/N
5. Please write your remarks and comments below
Thank you.
8/14/86
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