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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