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EEC 132B UNIVERSITY OF CALIFORNIA, DAVIS
Department of Electrical and Computer Engineering
EEC 132 B
LABORATORY
MANUAL
A. BUCK J. CAMPBELL
G.R. BRANNER
CONTENTS
Page 3 Laboratory Procedural Rules
Page 4 Laboratory Report Format
Page 5 Laboratory 1 Impedance Transformer
Page 13 Laboratory 2 Distributed Low Pass Filter
Page 17 Laboratory 3 Coupled Line Bandpass Filter
Appendix A Darkroom Procedure
Appendix B Instructions on Using TouchStone to
Download 8510 B/CS Parameter Data
Appendix C 8510B Instructions for Biasing and
Measuring Bipolar Transistor S-
Parameters
Appendix D 1dB Compression & 3rd Order Intercept
Appendix E MESA Revisited
3
LABORATORY PROCEDURAL RULES
1. Keep a bound lab notebook, loose pages are not acceptable (spiral binding is
acceptable). All data must be taken during lab time and entered into the notebook.
TA must review and sign data taken. A copy of the pertinent lab notebook pages
will be turned in as part of the lab report.
2. Lab manuals and supplemental handouts must be brought to lab every time.
3. Lab groups consist of no more than 2 people for labs done in EUII 3189.
EACH PERSON MUST TURN IN A SEPARATE LAB REPORT
4. Lab reports are due 1 week from the conclusion of taking data, due at the
beginning of the next lab time.
5. Enrolled lab times are not flexible.
6. At the beginning of lab there may be a 15 minute lecture/review of lab procedures
and relevant background.
7. At the conclusion of lab lecture there may be a 10 minute quiz on the laboratory
material. All laboratory material is testable at a later date.
8. All layouts must be complete at the beginning of lab, or you cannot start.
9. Layouts must be approved by the TA before beginning lab. Each student does
individual labs in EUII 3176.
4
LABORATORY REPORT FORMAT
EEC 132B
1.0 Introduction: 1.1 Describe the objective of the project
2.0 Design Technique: 2.1 Briefly summarize the design technique.
2.2 Provide pertinent circuit diagrams leading to the final design.
2.3 Make a table showing the desired dimensions, realized dimensions and
percent error.
2.4 Using a circuit simulator compute the response of the circuit using the
actual dimensions.
3.0 Experimental Results: 3.1 On the same graph plot the pertinent circuit responses for all circuits as
outlined in the experimental procedure. Include the back analysis.
3.2 Graph in-band and out-of-band responses on separate graphs. Clearly
mark design values such as fc, or ripple.
3.3 Provide tabulated measured and computed data.
4.0 Analysis: 4.1 Give a brief written comparison of your experimental and theoretical
results. Explain any discrepancies.
4.2 Answer all questions in the laboratory procedure.
5.0 Conclusions: 5.1 Briefly Summarize the project.
6.0 Appendices: 6.1 Netlist of schematic.
6.2 Last appendix should include hardware and mask.
5
Lab 1 IMPEDANCE TRANSFORMER Revision 1.1
1.0 Introduction
The purpose of this laboratory is to familiarize the student with the design and fabrication
techniques which will be used throughout the quarter. In this laboratory two circuits will
be fabricated and tested. The first circuit is a half-wavelength transmission line with a
characteristic impedance of 50 ohms. The second is a back-to-back stepped impedance
transformer.
In addition to assessing the fidelity of a fabricated 50 ohm microstrip transmission line,
the 50 ohm transmission line is used to determine the actual value of a 100 ohm resistive
termination procedure which is described in this manual. Two sets of measurements are
performed on the transformer realization. First the back-to-back transformer is measured
as a two-port network. Next, the transformer is cut in half and terminated with the
previously-measured resistive termination. This circuit is measured as one-port network.
The student will be required to:
1) Design and fabricate the circuits.
2) De-embed the transmission line characteristics from the 100 ohm termination
measurement.
3) Measure the required S-parameters of the circuits.
4) Write a laboratory report.
6
2.0 Prior Preparation
These items should be complete BEFORE coming to the laboratory.
1) Back-to-back transformer design.
2) 50 ohm half-wavelength transmission line design.
3) Layout for each design.
In addition you must have studied Appendix A "Darkroom Procedure" and "Darkroom
Use, Room 3182 Engineering II." Having these items complete before entering the
laboratory helps to insure that you do not spend time with the TA over Spring break.
3.0 Laboratory Procedure
In the laboratory you will photograph the circuit layouts and develop the film. The
negatives are used to make etch-resistant traces on treated copper clad boards. Etching
away all unprotected copper creates the circuit. You will mount connectors on the
circuits and measure the S-parameters using the HP 8510B/C vector network analyzer.
3.1 Circuit Layout
Layouts of your designs can be produced with the Libra computer program. Your layout
should be finished when you report to laboratory. Write you initials on the layout with a
felt tip marker, or draw text on the finished layout in Academy Layout so that they will
appear on the board for easy identification during laboratory.
Place alignment/sizing blocks so that they represent 5 cm in the final film mask when
measured between the OUTSIDE edges. In Libra, make the blocks 1970 mils from
outside edge to outside edge. When reduced on the 4x5 film, you will measure 5 cm
between the outside edges in the film mask.
7
3.2 Photography and Development
In this step the layouts are converted to negatives by photographing the layout and
developing the film.
3.2.1 Photography
1) Tape the layout on the wall at a convenient height for taking the picture.
2) Focus the camera.
3) Check the spacing of the alignment blocks with the sizing tool next to the camera.
If the tool does not fit exactly between the outside edges of the blocks, then move
the camera toward the wall to make them farther apart, or away from the wall to
bring them closer together.
4) Repeat steps 2 and 3 until the layout image is focused and the blocks are 5 cm
apart.
5) In the darkroom, with only the red light on, load a piece of film (emulsion side
facing the slide) into the film holder and slide the film cover into place. Take the
film holder to the camera.
6) Check the alignment and focus of the camera one final time and then close the
shutter.
7) Place the film holder in the camera with the film toward the front of the camera.
8) Cock the shutter. Pull out the film cover.
9) Click the shutter release to open the shutter and expose the film for 10 seconds.
10) Close the shutter and slide the film cover into the film holder on the side of the
holder toward the front of the camera.
8
3.2.2 Development
Follow the procedure in section II of the Darkroom Procedure (Appendix A).
Slide the film into the developer tank, immersing the film all at once. Time the
film development. Develop the film for 3 minutes. After 3 minutes of
development, remove the film from the developer and put the film in the fixer for
2 minutes. Wash film for one minute.
3.2.3 Fabrication of the Circuit Board
Follow the procedure given in the Darkroom Procedure (Appendix A). Use the
mounting blocks provided by the TA to mount the connectors to your circuits.
Connectors may be reused but the solder tabs are fragile and easily broken.
Screw the connectors to the blocks and blocks to the board first. When
everything is lined up and bolted down to your satisfaction, solder the connector
tabs to the board. Connectors can break if you solder them first, then bolt
everything down. (Do you have an extra connector should you break one at 8:00
p.m.?).
3.3 Measurement
First you will measure the 50 ohm line that will be used to determine the actual
value of a nominally 100 ohm termination. Then measure the back-to-back
transformer followed by one half of the back-to-back transformer terminated with
the 100 ohm termination. The HP 8510 will be calibrated in advance by the TA.
Use the Instrument State with the Start and Stop frequencies appropriate for your
center frequency. Do not change the start and stop frequencies. The calibrations
are only good over the frequency range used during calibration. Refer to the
instructions on using Touchstone to download the measured S-parameter data
from the HP 8510 to the PC. Use the file SPARTEST to download the S-
9
parameters from the HP 8510 to the PC. Make sure that you edit the start
frequency, stop frequency, and frequency step to match the network analyzer's
frequencies. A table of frequencies and frequency steps and the Instrument States
to which they correspond is in the instructions. Also, change the data file name to
something that makes sense to you. Copy the data file to floppy disk. There are 9
columns in the file. The first is frequency in GHz. The remaining columns are
the linear magnitude (not dB) and the phase of S11, S21, S12, and S22 in that order.
In other words, a row has Freq., |S11|, angle (S11), |S21|, angle (S21), etc.
3.3.1 50 Ohm Line Measurements
1) Measure the magnitude of S11 and magnitude and phase of S21 for the 50 ohm
transmission line. (Download all S-parameters from the HP 8510. Only S11 and
S21 will be of use in your lab report).
2) Replace the connector at one end of the transmission line with a short circuit
made from copper tape. Change the display to a Smith Chart and measure S11.
While measuring S11 change the value of the port extension until the display
shows a trace as closely resembling that of a short circuit as possible. Record the
value of the port extension for use in the next step. (You may want to see what a
calibration short from the calibration kit looks like for comparison).
3) Replace the short with a 100 ohm chip resistor. Measure the value of the resistor
with the same port extension from the previous step. (Take the S-parameters).
Note how the resistor is positioned with respect to the end of the transmission line.
When solding this resistor to the stepped impedance transformer, try to duplicate
the resistor position.
4) Change the port extensions back to the calibration values (recall the instrument
state). Measure the magnitude of S11 for the 50 ohm transmission line terminated
with the same 100 ohm chip resistor measured in 3.3.13.
5) Use calipers to make precise measurements of the length and width of the line.
10
3.3.2 Back-to-Back Measurements
Measure the magnitude of S11 plus the magnitude and phase of S21 for the back-
to-back transformer.
3.3.3 Stepped Impedance Transformer Measurements
1) Cut the back-to-back transformer in half and attach the same 100 ohm chip
resistor measured in 3.3.1.3.
2) Measure the magnitude and phase of S11.
3) Use the calipers to make precise measurements of the actual lengths, widths and
dielectric thickness of your circuit.
3.3.4 Summary of Laboratory Measurements
TABLE 1. Summary of Measurements
50 Ohm Line S21 Magnitude(dB) and Phase
S11 Magnitude(dB)
50 Ohm Line Terminated in 100 Ohm Resistors S11 Magnitude (dB) and Phase
Back-to-Back S21 Magnitude (dB) and Phase
S11 Magnitude (dB)
Transformer Terminated in 100 Ohm Resistors S11 Magnitude (dB) and Phase
11
4.0 Analysis
This section lists the concepts which, at minimum, you must address in your report.
4.1 50 Ohm Transmission Line
1) State reasons why the through loss and input reflections are not equal to zero
for the 50 ohm line.
2) From the through phase measurements, determine the electrical length of the line
at your center frequency. What is the percent error between the measured
physical length of the line and the measured electrical length of the line? What is
the source of this error?
4.2 50 Ohm Transmission Line Terminated with a 100 Ohm Resistor
1) Compute the measured impedance of the resistor.
2) Tabulate the complex impedance and the magnitude and phase of S11.
3) Determine an equivalent circuit for this resistor.
4.3 Back-to-Back
1) From your data can you predict the performance of the impedance transformer?
12
4.4 Impedance Transformer
1) Compute the theoretical transformer response using the actual measured values
for length and width of the lines. This is called a back analysis.
2) Use the impedance values of the 100 ohm resistor to compute the transformer
response.
3) On one graph, plot the magnitude of S11 (dB) of your impedance transformer for
the following cases:
(a) Designed simulated response
(b) Fabricated measured response
(c) Back analysis response
Clearly label each curve on the graph and indicate your center frequency, passband and
design specs. Plot the response over a range of frequencies that makes sense for your
center frequency.
4) Give a brief written comparison of your experimental and theoretical results,
explain any discrepancies.
5.0 Report
Write a lab report which conforms to the format specified in the handout "Laboratory
Report Format."
13
Lab 2 Distributed Low Pass Filter Revision 1.1
1.0 Introduction
The purpose of this lab is to design and fabricate a low pass filter using microstrip
elements. The final design will be fabricated as in the previous lab.
2.0 Prior Preparation
Design a low pass filter using the techniques from lecture. You may use either MESA or
Libra to design the filter. The TA will provide an example file which can be used for
familiarization with Libra. Make a layout similar to the one for the quarter wave
matching network fabricated in the previous lab. The filter must be designed and the
layout complete before the beginning of the lab. The TA will have to approve your
layout before you may continue with fabrication during your appointed laboratory time.
2.1 Tuning the Design
Use Libra to fine-tune your design by:
(a) Placing the identical design which was run with MESA on Libra and plotting the
response.
(b) Replace Cstp values with MSTEP and plot the response.
(c) Fine-tune the design using Libra to provide an exact match at your -3dB
frequency. CAUTION: Element length changes should be kept to less than 20%.
(d) Be sure to plot all three of these new curves on the same graph.
14
3.0 Laboratory Procedure
In the laboratory you will fabricate and assemble the low pass filter in a very similar
procedure to that used for the transformer which was made in Lab 1. Then you will make
measurements of the S-parameters of the filter and of the dimensions of the completed
filter.
3.1 Fabrication and Assembly
Photograph your circuit layout, develop the film and etch the circuit. Refer to you notes
and the handouts if you are unsure of any steps.
3.2 S-Parameter Measurement
Refer to the instructions on using Touchstone to download data from the 8510 to the PC.
Use the Network Analyzer to measure the S-parameters of the filter. Use the file
SPARTEST.CKT to download the S-parameters from the 8510 to the PC. Make sure that
you change the start frequency, stop frequency, and frequency step to match the network
analyzer. Also change the file name to something which makes sense to you. Copy the
data file to floppy disk and carry this disk with you always. Protect it with your life. It
now contains data you must have in order to write your lab report. There are 9 columns
in the file. The first is frequency in GHz. The remaining columns are the linear
magnitude (not dB) and the phase of S11, S21, S12, S22 in that order. Make any hard-
copy plots of this data which you feel should be included in your report. By now you are
expected to be able to determine what is important; if you need assistance, ask the TA.
3.3 Actual Measurements
Use calipers to measure the length and width of the completed filter elements.
15
4.0 Analysis
This section lists the concepts which, at a minimum, you must address in your report.
4.1 Back Analysis
Using the actual values of the filter elements use Libra to determine the simulated filter
response. The handout "Procedure for Touchstone and Libra on Workstations" contains
detailed information on starting Libra. The TA will provide instruction on using Libra
for this purpose.
4.2 Plots
Plot the insertion loss for the lumped element design, distributed design, measured
response, and back analysis all on a single graph. Repeat this graph over different
frequency ranges and/or amplitudes to demonstrate the in band response, out of band
rejection and periodicity of the filter. Clearly label each curve and indicate the cutoff
frequency and design specifications.
4.3 Final Design
Show the final layout and the final design specifications on the same page with the filter
layout. Use the table format below to present your final values. Computed values
(comp) are the values computed using the measured values. Give a brief comparison of
the experimental and theoretical results. Explain any discrepancies.
16
TABLE 1.
Distributed Value LUMPED Z0 WIDTH LENGTH
VALUE Theory Comp %Error Design Meas %Error Design Meas %Error
Fc (original design) = Fc (final design) = Fc (measured) =
5.0 Report
Write a lab report which conforms to the format specified in the handout "Laboratory
Report Format."
17
Lab 3 Coupled Line Bandpass Filter Revision 1.1
1.0 Introduction
The purpose of this lab is to design and fabricate a coupled line bandpass filter using
microstrip elements. The final design will be fabricated as in the previous labs.
2.0 Prior Preparation
Design a bandpass filter using the techniques from lecture. Students may use either
MESA or Libra to tune the final design as necessary. Fine tune the design as explained in
Lab 2, Low Pass Filter, if necessary. Make a layout using Libra. The filter should be
designed and the layout complete before the beginning of the lab.
3.0 Laboratory Procedure
In the laboratory you will fabricate and assemble the filter as in previous labs. Then you
will make measurements of the S-parameters of the filter and of the dimensions of the
completed filter.
3.1 Fabrication and Assembly
Photograph your circuit layout, develop the film and etch the circuit. Refer to your notes
and the handouts if you are unsure of any steps.
18
3.2 S-Parameter Measurement
Use the Network Analyzer to measure the S-parameters of the filter. Use the file
SPARTEST.CKT to download the S-parameters from the 8510 to the PC. Make sure that
you change the start frequency, stop frequency, and frequency step to match the network
analyzer. Also change the file name to something which makes sense to you.
3.3 Actual Filter Measurements
Use calipers to measure the length and width of the completed filter elements.
3.4 Optional Measurements
Shorten the coupled sections by an appropriate amount (see figure 3b of Cohn handout)
and repeat section 3.2. First test your proposed circuit trim procedure on Libra before
putting your physical circuit under the knife. Note: Length can be added with copper
tape if you go too far, but the simulator can be used to good advantage here.
4.0 Analysis
This section lists the concepts which, at a minimum, you must address in your report.
4.1 Back Analysis
Using the actual values of the filter elements use Libra to determine the simulated filter
response.
19
4.2 Plots
4.2.1 In Band Loss
On the same graph plot the insertion loss for the following cases:
(a) lumped-element design
(b) final distributed design (from part g of special problem)
(c) measured response
(d) back analysis
Use a full-scale value of 4 dB. Clearly label each curve on the graph and indicate your
center frequency and design specs.
4.2.2 2-6 GHz Plots
Repeat 4.2.1 over a frequency range of 2-6 GHz. Use a scale which shows the features of
importance.
4.2.3 Optional Plots
Repeat sections 4.2.1 and 4.2.2 for the modified filter of section 3.4.
4.3 Final Design
Show the final layout and the final design specifications on the same page. Use a table
similar to the ones used in previous labs to present your final values.
20
4.4 Evaluation of Results
Give a brief written comparison of your experimental and theoretical results and explain
any discrepancies.
5.0 Report
Write a lab report which conforms to the format specified in the handout "Laboratory
Report Format.
1
APPENDIX A
132 B/C DARKROOM PROCEDURE
2
EEC 132 B/C DARKROOM PROCEDURE PLEASE WEAR GLOVES WHEN YOU ARE WORKING WITH CHEMICALS.
PLEASE DO NOT OPEN CUPBOARDS UNDER REGULAR LIGHT.
Outline of Procedure:
Red light only:
Load film holder
Develop, fix film
Yellow light:
Coat board with photoresist, develop board.
Film:
Expose: 20 seconds
Develop: 2 1/2 to 2 3/4 minutes (pull out and check)
Fix: 2 minutes
Wash: 1 minute
= a procedure that must be done under a red light
= a procedure that must be done under a yellow light
3
Board:
Clean: with propanol and steel wool (very lightly)
Coat: uniformly with KPR resist
Bake: one hour
Expose: 3 to 3.5 minutes
Develop: 3 to 3.5 minutes
Rinse:
Dry uncoated side
Tape back
Etch: 10-20 minutes
NOTE: Big boards take longer to etch and are likely to develop irregularities such
as ragged edges, pinholes, etc. Keep boards small. Small boards with
little surplus to be trimmed give good results predicted by Libra. Big
boards that must be trimmed excessively, do not.
= a procedure that must be done under a red light
= a procedure that must be done under a yellow light
4
DARKROOM PROCEDURE
PRECAUTIONS
The procedure of photography, developing and fabrication of circuit boards involves the
use of hazardous chemicals, which have the capacity of causing temporary or
permanent damage to health. Therefore, it is MANDATORY that the following
precautions be observed at all times during the process:
(a) Use laboratory coats or aprons at all times
(b) Use gloves at all times when handling chemicals
(c) Use goggles for eye protection
PHOTOGRAPHY
1. Under the red light take a 4x5" Kodalith film sheet from the cupboard and load it
into the film holder.
The dull or darker emulsion side faces out toward the light source. Replace the
remaining film back in its box and put back in cupboard.
(a) Remove the slide from the film holder.
(b) Open the hinged light trap.
(c) Slide the film into the film holder, keeping both edges of the film behind the guide
rails. The film must be perfectly flat in the film holder.
(d) Close the hinged light trap.
(e) Replace the slide into the slot on the same side as the film.
(f) Load the film holder into camera, remove the slide and expose the film to the picture
of the circuit on the wall for 20-25 seconds at f8 (this is using the fluorescent lights
from ceiling. Or, if using approx. f11 with incandescent light source at 8 seconds.
= a procedure that must be done under a red light
= a procedure that must be done under a yellow light
5
(g) Replace the slide. Be sure you've put the slide in the frontmost slot where it will
keep light from the film, and then remove the film holder from the camera.
(h) Remove the film from the film holder. Submerge the film in A&B solution
(developer). Slip the film into the developer at once, emulsion side up so that the
entire film is immersed simultaneously.
(i) Agitate once every 30 seconds by lifting one end of the developing tank about
1/2" off the counter, and setting it back on the counter. Continue agitating until the
2.5 minute mark (5 agitations total during development).
(j) At 2 minutes, 45 seconds, pick up the film from the tank and let drain until the 3
minute mark.
(k) Submerge film into photo fixer solution for 2 minutes. Agitate the same way as
developer. (The fixer stops development and makes the film no longer light-
sensitive).
(l) Take the film out and wash under running water for 1 minute. Hang the film up to
dry. The dried film is the mask for your circuit board. Handle it carefully and keep it
clean. It should look something like this:
Tongs or forceps may be used to handle the film during development, but for best result,
use your fingers. Just be sure to wash your hands after getting them in chemicals!
= a procedure that must be done under a red light
= a procedure that must be done under a yellow light
6
FABRICATION OF CIRCUIT BOARD
(a) Cut a minimum size circuit board piece appropriate for your circuit dimensions. You
should know the dimensions before you start. Use the cursor in Libra to measure
your layout.
(b) Buff and rub (very lightly) one side of the circuit board piece with fine steel wool
(#000).
(c) Use propanol and Kimwipes to take dirt and dust off from the buffed side.
(d) The surface of the circuit must be dust-free and very clean. Handle the cleaned board
only by the edges.
(e) Wearing gloves for this part of the procedure is mandatory under yellow light in
the darkroom. Take the bottle of photoresist (KPR) and pour a uniform layer of KPR
on your circuit. Don't let your circuit touch anything. Pour a small amount at one
edge of the board. Rock the board side-to-side as you let the KPR work its way to the
opposite edge, uniformly coating the cleaned side of the board.
(f) Let the chemical drip off by holding your circuit as the figure below illustrates:
Note: To keep the board from falling while the KPR drains, carefully tape it to the side
of the fume hood. Apply a small piece of tape to the backside (non-KPR-coated) of the
board, but do NOT let the coated side come into contact with the side of the fume hood.
Lean the board against the fume hood, tape the top corner of the board.
= a procedure that must be done under a yellow light
7
(g) Do not relayer circuit, because relayering the circuit causes a multilayer of KPR
photo resist on circuit board that causes uneven etching and non-uniform circuit
dimensions. If the coated side falls on anything before it has been baked, use KPR
developer as a solvent to remove all of the KPR resist. Clean the board with propanol
and steel wool and start again.
(h) Bake your circuit in the oven for 60 minutes. Replace the oven door lid and leave
the lid open about 1" at the bottom.
(i) Take your circuit out of the oven. Let it cool down. Please be careful as the oven
is very hot!
(j) Lay the film mask on the KPR-coated side of the circuit board. Place the mask,
emulsion side down, on the contact printer glass, the board will be on top of the
negative. Expose 3 minutes under ultraviolet light. DO NOT LOOK INTO THE
ULTRAVIOLET LIGHT DIRECTLY! IT IS HARMFUL TO THE EYES!
(k) Submerge the circuit into KPR developer for a minimum of 3, maximum 3.5
minutes; agitate once. Replace the cover, keeping the KPR tank in the fume hood.
Continue agitating as was done with the film developer.
(l) Remove the board after 3 to 3.5 minutes developing time. Rinse under running water.
Dry the board thoroughly. Do not scratch the KPR side. Handle the board by the
edges only.
= a procedure that must be done under a yellow light
8
(m) Tape the bottom of the circuit board with paper underneath the tape (minimizing
clean up). Make sure that the tape has stuck to the bottom firmly. It must cover the
entire bottom of the board. You do not want the etchant to come into contact with the
bottom of the board.
(n) Mix determined amount of ammonium peroxidisulfate powder in hot water and keep
the solution (etchant) warm by placing the solution in a container on the burner in low
heat (11 o'clock). The etching process should be done inside the hood only.
Submerge the circuit into the etchant and gently agitate the circuit until the copper
etches away.
DO NOT TOUCH THE SURFACE OF THE CIRCUIT!
This should take 25-35 minutes. Do not let the etchant boil. Never set the hotplate
thermostat past 12 o'clock. After etching, rinse the circuit with water and remove the
masking tape
1
APPENDIX B
INSTRUCTIONS ON USING TOUCHSTONE
TO DOWNLOAD 8510 S PARAMETER DATA
2
d: Assuming the machine is starting in the Touchstone operating system from a
warm boot, or power on (you will see a C:\> prompt). See note at the end. Stuff
in boldface is what you type. You must see a D:\> prompt before continuing.
cd eesof3
touchstn
Hit any key to remove the "hideous" colors. If you don't, the next keystroke you
make will be ignored, and you'll be in "La-la" Land.
Shift F7 (Chdir) data132c
If you don't do this, your data will magically appear in directory D:\eesof3\tsdata\.
Try looking there if you don't see it in D:\eesof3\data132c\. You can show to
which directory your data will go by Shift F8 (Shdir).
Shift F3 (Read) spartest
This loads the S-parameter test program.
F5 (Edit)
Edit the file. You are in OVERWRITE mode by default, so no need to backspace.
If you want INSERT mode, toggle the mode by hitting the INSERT key. Edit the
line for your filename, and the line for the frequency sweep. We're using
filenames consisting of your first two initials, the start and stop frequencies, then
you have up to 4 characters to use (DOS restricts you to 8 characters before the
file extension) to name the file something meaningful to you. The impedance
transformer lab generates many data files, so be sure you know which ones
contain the data for each load condition, short, chip resistor, etc.
8510
Instrument State
8510 Start Freq
(GHz)
8510 Stop
Frequency
SPARTEST Start
Frequency
SPARTEST Stop
Frequency SPARTEST Freq.
Increment
3 1 3 1 3 0.01
4 2 4 2 4 0.01
5 3 5 3 5 0.01
6 2 6 2 6 0.02
7 1 6 1 6 0.025
8 2 12 2 12 0.05
3
F2 (Exit)
When you have edited the appropriate lines, if you don't alter the FILENAME,
your last measurement data will be lost when your next measurement sweep
overwrites the previous measurement file.
F8 (Sweep)
"Prepping ckt file" appears for a while, then a screen filled with S11 (dB), S11
(degrees), VSWR appears. Do not panic if you were looking at S21 a minute ago
on the 8510 and saw a low insertion loss of 0.2dB, only to find -32dB on the PC
screen. (1) All you data is on disk in the file you named, S11, S21, S12, S22 (in
that order, magnitude--not dB--and phase), the screen display has nothing to do
with your .s2p file. (2) What you see on the PC is S11 (dB), Return Loss, which
should be rather small if the impedance match is good. The screen data is
completely separate from your \disc data. Also, there is fluctuation in the
measurement, so even if you were looking at S11 of -32dB, only to see -32.1dB on
the PC, they are very close to one another in magnitude, the difference is due to
the time between the different measurements. When you go back to the 8510B, it
will be displaying S11 because Touchstone left it that way.
To copy your data files to floppy disc, assuming you are now in the
D:\eesof\directory:
When all your data for a lab has been taken, exit Touchstone and return to DOS with:
Shift F10 (Stop)
Obvious, no? No. But that's how you quit the program. Touchstone will ask you if you
are serious, type "Y" for yes, Carriage Return, and it will dump you back at the
D:\eesof>prompt.
cd data132c
copy <Your Filename Here> a:
Continue will all your files, or you could do a batch, using your unique initials:
copy ZZ*.s2p a:
Assuming your initials are ZZ.
Please restore the Touchstone setup for the next person:
4
cd ..
touchstn
Any key
Shift F7 data132c
Shift F3 SPARTEST
Now the next person is set up with SPARTEST open, ready to being editing with F5.
If you ever type TOUCHSTN and get an error message: "Abnormal program
termination," that cryptic error message means that the computer is set up with the
network operating system and must be rebooted (a warm boot, Control-Alt-Delete).
When a two-item menu appears, hit Carriage Return for the Touchstone operating system,
the default, not the network OS.
1
APPENDIX C
8510B INSTRUCTIONS FOR BIASING AND
MEASURING BIPOLAR TRANSISTOR
S-PARAMETERS
2
8510B Instructions for biasing and measuring bipolar transistor S-parameters
(AT41435, AT41485)
High-frequency transistors have a very narrow base region to minimize base transit time.
Hence, the base-emitter junction is particularly susceptible to electrostatic discharge
(ESD) and overvoltage. In order not to destroy your transistor, it is imperative to follow
the procedure below to protect your transistor against ESD damage and improper biasing.
Always wear a wrist strap when handling the transistor. Use tweezers, not your fingers.
Turn on VCE first, then apply base bias (via the IC) knob. Reversing this order, applying
base current first, will destroy your transistor. Conversely, when turning off the transistor,
removing VCE before turning off the base drive, IC, will damage the transistor. Even if
the transistor does not fry, its noise and frequency response characteristics will be
seriously degraded. Please follow these instructions in the exact order as written, and
your transistor will last the quarter. Be sure to read each step completely before carrying
out the instruction.
1. Check 8717B Transistor Bias Supply, be sure the center Bias on/off switch is not
illuminated.
2. Put on the wrist strap.
3. Open test fixture, pressing in both metal side buttons simultaneously, lifting
plastic lid handle.
4. With HP label down on the table, open transistor package carefully with the
tweezers, removing the top, showing the transistor, body and marking down.
5. Touch the tweezers to side of test fixture to discharge any residual charge.
6. Pick up transistor by one of the EMITTER leads, with base lead (angled end)
pointing to the left.
7. Place transistor in fixture, body down, leads on top, with base lead to left,
connecting to Port 1. Be sure transistor is centered and flush with the contact
surfaces. Push it as far to the left as it will go; the emitter leads should contact the
left side of the slot, minimizing the distance to Port 1. The AT41485 has shorter
leads, so aligning the emitter leads with the slot can be troublesome.
8. Close lid on fixture pushing down firmly; be sure it latches.
3
9. Check the 8717B Transistor Bias Supply: With the settings used here, the current
and voltage limits preclude the possibility of damage. However, getting the steps
in the wrong order can cause damage.
a. Both black knobs fully counterclockwise (do not change the red center IC
range knob)
b. Turn on center Bias On/Off pushbutton switch
c. Turn VCE knob clockwise until meter shows 8V
d. Turn black outer IC knob clockwise until meter shows 10mA. This is a
non-linear controlóbe, careful, the current increases more as you pass 12
o'clock.
10. Check S-parameters on 8510B screen with Instrument State 7 recalled (if not
previously set up in this state). Vary IC to see the effect on S21, S11, S22. Return
IC to 10mA before continuing.
11. Remove the wrist strap.
12. To the PC:
a. Shift F3 (Read) AT41435 (load the program for the transistor parameters,
if not loaded previously).
b. F5 (Edit) Edit the filename only, do not change the frequencies or step size.
c. F2 (Exit).
d. F8 (Sweep) This takes 1.25 minutes.
13. Put on the wrist strap.
14. Reverse settings on the 8717B Transistor Bias Supply
a. Turn IC knob counterclockwise until meter shows 0mA.
b. Turn VCE knob counterclockwise until meter shows 0V.
c. Turn off the center Bias pushbutton switch.
15. Open the fixture, pressing in both metal side buttons simultaneously, lifting
plastic lid handle.
16. Touch the tweezers to the side of the fixture.
17. Pick up transistor by one of the emitter leads.
18. Replace transistor into its package, body facing down.
19. Replace lid on package.
4
20. Remove wrist strap.
21. Save data to floppy disc.
Switch settings: State all switch positions for 132C transistor measurements. Calibration
procedure.
1
APPENDIX D
1dB COMPRESSION
AND
3RD ORDER INTERCEPT
2
-1dB Compression and Third-order Intermodulation Distortion Intercept Point
Measurements.
fT
Put your transistor into the expensive transistor test fixture on the 8510. Bias the
transistor. Recall Instrument State 2. This sweeps from 1GHz to 12GHz. Find the
frequency at which S21=0dB. You can use the Marker to search for the target, 0dB. This
frequency is fT. Record the magnitude of S21(dB) at 1, 2, 4 GHz. You will need the
4GHz value to verify your calculated IP3. (In case you did not use Touchstone in an
earlier lab to collect the S-parameters on the transistor you are now using for device
characterization, you can now record by hand the complete complex S-parameters at
2GHz for calculating NF.) The 8510 can give you values in straight magnitude and in dB,
check out the Format Menu button and the softkey choices. Turn off the transistor
biasing. Remove your transistor.
Power Level and Distortion Test Set Calibration
First you need to determine the actual input power to the Device Under Test (DUT), the
base of the transistor, and the actual power at the collector. This will allow you to record
the synthesizer output power and correct it later for DUT input power delivered to the
transistor base, and to record SA input power and calculate the actual DUT output power.
Your calculations will be in DUT input/output power, not the power indicated in the
equipment displays. There is a -10dB pad between the DUT output and the SA, so 10dB
more than what is indicated on the SA is actually being delivered by at the collector of
the transistor. (This is a calibration not unlike some of the error terms used in a network
analyzer calibration.)
Be sure the bias supply is off. Insert the calibration through (small straight piece of metal,
not the X-shaped piece) into the transistor test fixture and close it. Turn off the RF power
from the 4.1 GHz generator. Set the 4.0 GHz synthesizer to -10dBm output power and
turn on its RF power. There should be a peak on the spectrum analyzer (SA) display at
4.0 GHz. Be sure video averaging is off on the SA. Set the marker to the 4.0GHz peak.
Wait for the Marker amplitude readout to stabilize, this takes 2-3 sweeps. Record the
synthesizer power level and the marker power level. Increase the synthesizer power,
3
recording the magnitude of the SA marker. You needn't record this in too fine a step
increment, but you should go through the range of -10 to +20dBm (5dB steps works) to
ensure the difference between the synthesizer output and the SA input power is constant.
-1dB Compression Point
Insert your transistor into the test fixture. Bias the transistor as described in the
procedure for measuring S-parameters, with proper supply sequencing. Turn on the RF
power from the 4GHz synthesizer. Based on your measurement of |S21| at 4GHz and the
above calibration, does the measured output power make sense with respect to the DUT
input power? In 1dB increments starting with 5dBm, ending at 20dBm on the synthesizer
display, increase the synthesizer power and record the marker magnitude at 4GHz. For
every 1dB increase in Pin, you should see a 1 dB increase in Pout. Take enough data
points to show the gain compression: 1dB increase Pin yields less than 1dB increase in
Pout (go up to +20dBm on the synthesizer display). You will plot these data and find
where the straight line low-power curve diverges from the high power transfer
characteristic. When you reach +20dBm on the synthesizer, increase the SA frequency
sweep by setting the Start Frequency to 3.9GHz and the Stop Frequency to 12.1GHz to
see the second (HD2) and third (HD3) harmonics coming up out of the noise as you
increase power. These spurs give rise to the intermodulation products. Decrease the
synthesizer output power and record the synthesizer power output levels at which first,
HD3 and second, HD2 disappear into the noise.
Spectrum analyzers have two major modes of displaying frequency information. They
can sweep between a start and stop frequency, or over a span (or bandwidth) with a
prescribed center frequency. When you are done, return the SA center frequency to
4GHz and the span to 1GHz. Reset the synthesizer output power to -10dBm, and turn off
the RF output power.
4
Analysis
Calculate the DUT input power when the DUT output power is 1dB less than that
predicted by the linear extrapolation of Pin vs Pout at low power levels. Extrapolate a
line from the low-power data. Trying to do a regression line on the whole data set will
lead to erroneous results. This is the input power level at which -1dB gain compression
occurs, the -1dB compression point.
IP3
Turn on the RF output power on both generators. Increase the synthesizer outputs to
+10dBm. In addition to the generator frequency peaks at 4.0GHz and 4.1GHz, you
should see spurs arising from the noise at 4.2GHz, and at 3.9GHz. These are the third-
order intermodulation (IM) products. (Theoretically they should be identical in
magnitude, given identical input power from the two synthesizers, but mismatches in the
input paths will cause a difference.) You may want to use the Marker Peak Search
function (be sure the Peak Threshold is set to a value that will allow you to pick up the
peaks) to set the marker to track the larger spur. Because it is tough to lock onto the IM3
spur frequency when power is reduced, don't mess with the Marker or you will lose it.
Reduce the synthesizer powers together until the IM spur falls back into the noise (this
happens at about 0dBm on the front panel display).
Increase the power outputs of the synthesizers together in 1dB increments. Record the
synthesizer output power and the marker power at the IM3 spur being tracked. You
should soon reach a range in which a 1dB increase in input power yields a 3dB increase
in transistor output power 5 to 10dBm synthesizer output power. This is the small-
distortion region in which the equations for IM3 derived in class and homework are valid.
Once you pass the small-distortion region spurs will appear at 3.8GHz and at 4.3GHz.
These are fifth-order IM products. At that point there are higher order distortion products
which will mix and contribute to the distortion components at the IM3 frequencies.
These were not taken into account in our derivation.
Record the generator power and the DUT output power until you reach a point in which
the Pout no longer increases 3dB at each step. Return the synthesizers to -10dBm and
5
turn off the RF output power. Turn off the SA video averaging. Turn off the transistor
bias in the proper order and remove your transistor.
Analysis
Fit a straight line to the low-power linear region of the fundamental (4GHz) power
input/output data. Fit a straight line to the 1dB-in/3dB-out IM data. This is a much
narrower range of input power than the measurement of the fundamental power. Solve
the two linear equations for their intersection. The extrapolated input power where the
fundamental and third-order intermodulation product output powers are equal is the third-
order intermodulation intercept point, IP3 or TOI.
SA (hp8563E) settings: Peak threshold: -76dBm (or as necessary to search out the
relevant peaks), Center freq: 4GHz, Span: 1GHz, Ref Lvl: -7dBm, RBW
Manual=300kHz, Vid BW Manual=3kHz, VBW/Span ratio: 1.0, RBW/Span ratio, 0.011,
VID AVG: off (Sweep time came out at 2.8 sec).
TA Instructions
For this lab, it progresses quicker if students work in a moving average tag-team manner.
Student (1) takes data and operates the SA, student (2) helps punch buttons on the
synthesizer, then (2) takes data, and student (3) helps, etc. It goes much faster having
seen it once. The first student can easily take 45-60 minutes taking data, reading
instructions, trying to figure out what's going on. A student who's seen it through once
before takes about 20-25 minutes. I had the first student of the evening go through the
calibration procedure, and all shared the data, as it doesn't change, and takes time. But
everyone saw what was done.
Instructions: Background, reasoning first, then tell them how to punch buttons.
8510 Calibration: cal8510B, 7mm full 2-port, 1-GHz, connect Q fixture, insert short, dial
in port extension to get short on Smith Chart S11, about 0.082ns. Check through on S21,
6
within 0.1dB of 0dB, save Instrument State 7 (step sweep, not ramp for better phase data).
Do same, 1-12GHz, Instrument State #2.
General 8510 Calibration. P source 1=P source 2=-10dBm, Port ext. =0s, delete
appropriate Cal Set (NOT Cal Kit!), full 2-port cal with appropriate connectors. With
3.5mm full 2-port cal, put short on Port 1, dial in port extension of 0.032ns, should be a
dot at 0SYMBOL 87\f"Symbol". Save the Instrument State with some mnemonic for
frequency range. IS3: 1-3GHz, IS4: 2-4GHz, IS5: 3-5GHz, IS6: 2-6GHz (all ramp sweep
for faster data collection). Trick with 7mm, 2 loads, lowband and wideband, wideband
load for isolation. 3.5mm cal, speed things up by using male termination in through
barrel. 1. Reflection, end with load on one port. 2. Isolation. 3. Transmission changes
fewest number of loads, can do loads on one port while other port calibrates. There is
now one 7mm cal kit with both a tape (visible) for the 8510B and a disc (under the
bottom foam) for the 8510C. Unless the cal kit data is trashed, this should be intact and
there should be no reason to reload it.
1
APPENDIX
E
MESA REVISITED
2
MESA Revisited
To get this out of the way first! MESA runs on any regular ECE UNIX workstation.
You no longer need to telnet to Sweetpea and use VMS, FTPing files between VMS and
UNIX. Sweetpea doesn't even have EDT (what VI is to UNIX, EDT is to VMS). There
are no Sweetpea accounts. Don't ask. Use your normal ECE account.
The MESA handout has references to a system of data entry that is extinct today, but was
all the rage when Steve Wozniak was in diapers. To help translate those instructions into
modern terminology, I will explain the terminology and how to construct a text file with a
text editor that MESA will interpret the way you want it to do. These instructions are an
adjunct to, not a replacement for, the original MESA handout.
Call it the Rosetta Stone for MESA!
The MESA instructions refer to column numbers for the data fields. These were the
actual column numbers that appeared on 80-column key punch cards. Machine-readable
data took the form of rectangular holes punched into the card by a machine called a
keypunch. Your program consisted of a deck of punched cards, each card contained one
line of your program, or one line of data. FORTRAN wanted fixed-length, fixed-location
data fields. Today the data are free-format, but are delimited by commas terminating
each field. Think of the commas as signifying the end of a variable-length (or fixed-
length) number that MESA needs to process. If only the first and the second data fields
are to have a value, one comma must appear after the first number, one after the second
number, then a bunch of commas appear to terminate the intervening (blank) fields.
Fields can be made blank (or null) in place of a zero, just to make life more confusing. I
try to put a (redundant) zero in the appropriate place to remind me that there was
something I cared about in that space.
3
This will all be clearer after the fifth reading, staring at a few examples and doing some
MESA computer runs yourself.
OUTLINE of MESA Decks and Cards
MESA decks (sometimes you still hear people refer to a SPICE deck, when they mean a
text file containing SPICE statements: SPICE started on FORTRAN with 80-column
cards, too!) have their first line as a Title Card (from the vestigial deck). As far as I know,
this can contain anything you want.
Line number two specifies the frequency sweep. This is the range of frequencies over
which you want the analysis, not unlike the AC analysis card in SPICE. It also rather
insidiously tells MESA the number of circuit ("component") elements there are for your
analysis. This is a common pitfall, forgetting to update this total number of circuit
elements field. MESA does not count the number of circuit element cards you give it, it
only analyzes up to the number of elements specified in this line. Be careful, especially
when editing previously-done files by adding new components or deleting old ones.
Line number 3 specifies the generator and load impedances.
Lines 4 and beyond specify each component, or circuit element. Line number 4 is the
first element the generator would see. The last element is what the load would see. You
don't specifically call out a generator or a load resistor component element, these
impedances were specified in Line #2, the Generator and Load Impedance Card.
MESA decks (text files) in more detail
Create your MESA input file using your favorite text editor (emacs, vi, notepad, pico, or
even Word, but save it as pure ASCII test with linebreaks). Be sure to hit the carriage
return after the end of the last line (this messes up HSPICE, too, perhaps for the same
reason). Save it under any name you like. File extensions are not important.
4
Line #1: Title Card
Not much to say here, whatever you want, give it something meaningful to you, as it will
appear as the first line of your output file, with a 1 stuck in front of it. Consider it to be a
glorified comment. (I know of no comment cards in MESA).
EXAMPLE
4 to 6 GHz amplifier, Transistor #1 unilateral, S-parameters, Real and Imaginary
Line #2: Frequency Sweep Card
Key requirements:
(0) Has ten (10) commas total, whether there is anything between them or not. The
commas terminate the fields, and there are 10 fields. Page 3 of the MESA handout is
misleading: the "Col. 16-20 -Blank" isn't really there, and there are 3 fields embedded in
"Col. 41-54 -Blank" (they're part of the parameter sweep).
(1) First number is the total number of circuit, or component elements in your file. An
easy way to remember is that it should be 3 less than the total number of lines in your
MESA input file. Count the number of lines in your file, subtract 3, this should be the
number before the first comma in Line #2. Weird error messages only slightly more
useful than Microsoft's and bizarre results follow if you fail to heed the warning.
(2) Second number is for the type of analysis. This number appears between the 2nd and
3rd commas. Most of the time this will be "3" for VSWR, Insertion Loss, Return Loss,
Forward Phase Shift. In 132C we'll use "4" for S-parameters.
(3) Third number is number of intervals in the frequency sweep. An even number will
include the median frequency.
5
(4) Fourth number is the Starting Frequency, in Hertz. Yes, 1 GHz is le9.
(5) Fifth number is the Stop Frequency, in Hertz. (Perhaps I should say cps-cycles-per-
second in keeping with decks and 80-column cards.)
(6) Usually end it with 6 commas after the Stop Frequency. In 132C we'll put a "1"
between the 3rd-to-the-last and the penultimate comma for Magnitude and Phase in the
S-parameters (i.e. ...<stop frequency>,,,,1,,).
EXAMPLES
3,3,52,3.125E9,4.375E9,,,,,,
3 components, VSWR etc., 52 frequency intervals between 3.125 and 4.375 GHz
1,4,30,1e9,4e9,,,,1,,
1 component, S-parameters in polar coordinates, 30 frequency intervals between 1 and 4
GHz
1,4,30,1e9,4e9,,,,,,
1 component, S-parameters in Cartesian coordinates, 30 frequency intervals between 1
and 4 GHz
1,4,30,1000e6,4e9,,,,0,,
1 component, S-parameters in Cartesian coordinates, 30 frequency intervals between 1
and 4 GHz
Line #3: Generator and Load Impedance Card
Generator Real, Imaginary load impedance, Load Real, Imaginary impedance. Only 3
commas between 4 numbers. Adding a fourth comma to end it doesn't hurt, though.
6
EXAMPLES
50,0,50,0
50Ω generator, 50Ω load, purely real
50,0,20,25
50Ω generator, 20+j25Ω load
50,0,50,,
50Ω real generator and load, showing how commas terminate blank (a zero value is
implied) fields, see comments, below.
Lines #4 to end of MESA deck: Component Cards
Key requirements:
(0) Has eight (8) commas total, whether there is anything between them or not. The
commas terminate the fields, and there are 8 fields. The page with the table
"COMPONENT CARD SYNTAX" of the MESA handout is correct. Just remember that
a comma follows each of the "Col." headings, including the last one, "Col. 71-80."
[Possible exception: a lossy line seemed to work with only 7 commas, no trailing comma
after the attenuation factor, or Loss(dB/cm) in the last field. It appears that a non-black
last value and a carriage return have the effect of terminating input, as is seen in the
Generator/Load card-4 fields with 3 commas. Apparently, an entry in the last field
terminates, and a final comma is not necessary in that case. Putting a final comma in
doesn't seem to hurt, though. This behavior is not documented, it's just Arne's
observation. Feel free to do some experimenting yourself.]
(1) First component is what the generator sees. Last component is what the load sees.
7
EXAMPLES
1,50,3,1,,,,,
50Ω lossless transmission line, air dielectric, 3cm. long
2,50,5,1,,,,,
50Ω lossless, air dielectric 5cm. long shunt stub
2,50,5,1,0,0,0,,
Long form of above component card, with Load Index, ReZ, ImZ called out. 50Ω
lossless, air dielectric 5 cm. long shunt stub
1,50,3,2,,,,0.001
50Ω lossy (0.001dB/cm) microstrip line εr =2.0) 3cm. long
21,,1,,,,,,
Unilateral transistor #21
21,,0,,,,,,
Bilateral transistor #21
22,0,1,,,,,,
Transistor #22, common emitter configuration, unilateral
14,2e-12,,,,,,,
Shunt inductor, 2pH
8
Run Time
To run MESA, log in to an ECE machine normally, type "mesa" at the Unix prompt, and
MESA responds with, "ENTER INPUT FILENAME." Type the name of the file,
carriage return, MESA asks, "ENTER OUTPUT FILENAME" so you do that, too.
Usually you get back to the Unix prompt after MESA has done its thing very quickly.
Open the named output file with your favorite text editor to see the results.
MESA is happy to overwrite existing files, so be careful. It won't overwrite your input
file, but you'll get whacko error messages giving you no hint as to why the program
bombed (probably some FORTRAN I\O error). Give it the name of a nonexistent input
file and you will get other cryptic error messages. Be sure you're in the right directory.
If you end up with a blank output file, delete that file from your subdirectory and run
MESA again. Sometimes MESA creates empty files for reasons I don't understand, and
will only behave itself if you start with a nonexistent file of that name and let it create it
again from scratch. Sometimes an errant non-printing character may appear in your input
file, and cause MESA to go south.
If you're really lucky, and hit an impedance match dead on, MESA will be unable to tell
you about it. I remember getting odd error messages. Try changing the number of
frequency intervals (go from 30 to 32, or 50 to 51), so as to move off of the one that is
dividing by zero, change the start and stop frequencies slightly (1GHz to 0.99 GHz), or
change a length or component value slightly. I remember "conversion error" showing up
on screen. Apparently that results when you try to divide by zero.
Trying to print via the Unix lp command always seems to lose the last column, ARG(S21).
If anyone has the answer to this problem, I'd like to know! I download the file to my PC
and print it in Word or Excel.
9
This is the MESA Input File. (This example is from the EEC132A Laboratory Manual,
Appendix A.4 Impedance Matching. There are a couple of errors in the manual in the
calculated single-stub tuner lengths, according to my Smith chart. Here are the correct
lengths, and the VSWR at 300 MHz demonstrates it. 0.386λ and 0.153λ , not 0.376λ
and 0.152λ )
Single Stub Example #2, Page 58 in Lab Notes, chose 300 MHz, correct lengths
2,3,20,200e6,400e6,,,,,,
50,0,20,-20
2,50,38.6,1,,,,,
1,50,15.3,1,,,,,
This is the Output File MESA creates (I underlined the 300MHz line):
1 Single Stub Example #2 Page 58 in Lab Notes, chose 300MHz, correct lengths
GENERATOR 5.000E+01 .000E+00
2 SHNT STB 5.000E+01 3.860E+01 1.000E+00 .000E+00 .000E+00 .000E+00 .000E+00
1 TRANS LI 5.000E+01 1.530E+01 1.000E+00 .000E+00 .000E+00 .000E+00 .000E+00
LOAD 2.000E+01-2.000E+01
FREQ VSWR(1) IL(12) RL(1) VSWR(2) IL(21) RL(2) ARG(S21)
MHZ DB DB DB DB DEG
200.00000 2.9083 1.1827 6.2269 2.9083 1.1827 6.2269 -21.5003
210.00000 2.7957 1.1003 6.5012 2.7957 1.1003 6.5012 -24.6894
220.00000 2.6615 1.0013 6.8633 2.6615 1.0013 6.8633 -28.0179
230.00000 2.5065 .8862 7.3381 2.5065 .8862 7.3381 -31.5363
240.00000 2.3319 .7561 7.9644 2.3319 .7561 7.9644 -35.3051
250.00000 2.1390 .6131 8.8055 2.1390 .6131 8.8055 -39.3990
260.00000 1.9294 .4608 9.9714 1.9294 .4608 9.9714 -43.9129
270.00000 1.7056 .3059 11.6740 1.7056 .3059 11.6740 -48.9678
280.00000 1.4708 .1606 14.4000 1.4708 .1606 14.4000 -54.7193
290.00000 1.2296 .0463 19.7462 1.2296 .0463 19.7462 -61.3636
10
300.00000 1.0118 .0002 44.6029 1.0118 .0002 44.6029 -69.1364
310.00000 1.3233 .0849 17.1289 1.3233 .0849 17.1289 -78.2872
320.00000 1.8439 .4003 10.5521 1.8439 .4003 10.5521 -89.0036
330.00000 2.7802 1.0889 6.5409 2.7802 1.0889 6.5409 -101.2599
340.00000 4.6152 2.3248 3.8246 4.6152 2.3248 3.8246 -114.6419
350.00000 8.6230 4.2890 2.0237 8.6230 4.2890 2.0237 -128.3299
360.00000 18.8926 7.1903 .9204 18.8926 7.1903 .9204 -141.3886
370.00000 54.1034 11.4707 .3211 54.1034 11.4707 .3211 -153.1632
380.00000 305.3029 18.8551 .0569 305.3029 18.8551 .0569 -163.4323
390.00000 13772.8259 35.3703 .0013 13772.8259 35.3703 .0013 7.7102
400.00000 244.0468 17.8896 .0712 244.0468 17.8896 .0712 .0331
