See previous projects for information on accessing and using HFSS software.

Overview

NOTE: Use the Project Report Template

IN NO CASE may code or files be exchanged between students, and each student must answer the questions themselves and do their own plots, NO COPYING of any sort! Nevertheless, students are encouraged to collaborate in the lab session.

Part 1: 3D simulation of parallel-plate waveguide

• In this part, we simulate a paralel-plate waveguide structure using HFSS software
• Run HFSS from the linux window menu using Mosaic::Engineering::Electrical::HFSS
• If this is the first time you run the software, make a note of the location of the default directory that will be created for your projects
• Store all projects in this directory
• Download the following project file (you may need to hold down the shift key while you click on the link):
• file:  e3122s19p4parPlate.aedt 
  
• Move the file into the HFSS directory
  
• Load the project from within HFSS using MenuBar::File::Open (red circle below)
• Double-click the "parPlate1" design (magenta arrow below), and select DrawTab (green arrow below), 
  
• 
  

Fig. 001

• Click the CreateBox (blue arrow above) and the dimensions of the box should appear in the PropertiesPane (blue box above)

• Make sure the message and progress panes at the bottom are visible by MenuBar::View::MessageManager and MenuBar::View::Progres
• Run the simulation by selecting the SimulationTab (red arrow below), and clicking AnalyzeAll (magenta arrow below)
  

Fig. 002

• When the progress bar shows the simulation is completed, double-click the s-parameter-plot2 (green arrow above) to see the s-parameters of the parallel-plate waveguide (yellow box above)
  
• Resize the plot to properly fit in a figure for your report, and make sure the axes are legible and plot is on scale, and save the plot for your report

• Open the ResultsTab (red arrow below), and open the SolutionData (blue arrow below)
  

Fig. 003

• Make sure the Zo check box of the report is checked (green arrow above), and observe the impedance of the line Z0 (magenta arrow above)
  
• Record the Zo above, and compare it to the calculated theoretical characteristic impedance for the parallel-plate TEM line

• You can inspect the perfect conductor top and bottom faces of the parallel-plate waveguide by clicking the PerfE boundaries as illustrated in the left figure below
• You can inspect the excitation waveports of the parallel-plate waveguide by clicking the excitations as illustrated in the right figure below

      

Part 2: 3D simulation of rectangular waveguide

• First, construct a WR90 waveguide and measure its S-parameters and cutoff frequency
• Run Applications::ElecEngineering::AnsysHFSS
• Then in HFSS run MenuBar::Project::InsertHFSSdesign as illustrated below
  

Fig 004

• Note: use MenuBar::View::ProjectManager if the project manager disappears on the left
  
• MenuBar::HFSS::SolutionType::Modal and NetworkAnalysis
  
• MenuBar::Modeler::Units select mm
• Next draw the waveguide as a box: MenuBar::Draw::Box  And at the bottom of the screen enter  x=0 y=0 z=0 mm, (yellow arrows below) and  then type "enter "or "carriage return" then type dx=100 dy=22.9 dz=10.2 mm, and  then type "enter "or "carriage return"

Fig. 005

• Alterntively, click the DrawBox tool icon (yellow arrow below), draw any box, click the "createBox" item (red arrow below), and edit the properties (blue arrow below) to set the Position=(0,0,0) and dimensions dx=100 dy=22.9 dz=10.2 mm as given above.
• Press the "fitAll" toolbar item (orange arrow below) to view the object.
  

when done it should look like:

Fig. 006

• To refit the view, use   MenuBar::View::FitAll::AllViews
• Select the waveguide box using MenuBar::Edit::Select::Object 
  
• then right-click the waveguide and AssignMaterial air  (this sets the entire volume of the box to be air)
  
• MenuBar::Edit::SelectionMode::Faces  then right-click the long waveguide top face,
  
• then select the box and the top face will hilight, then right-click::nextBehind to get the bottom plate,
  
• then right-click assignBoundary Perfect-E 
• and repeat this for the long top face. 
• In the same fashion assign the two long sidewalls as Perfect-E boundaries.
  
• Right-click the front face, and AssignExcitation::WavePort,
  
• in the popup: set name=input1, numberofmodes=1,
  
• click on the "integration lines=none" and select newline
• then click on the integration line field and select newline, 
• and draw a line (yellow circle below) from the center bottom of the port to the center top of the new port as in the example below, 
• click next, do not renormalize, and finish. 
  
• Repeat this for the second port at the far end of the waveguide, naming it input2
  

Fig. 007

• Highlight the excitation ports in the ProjectManger pane (blue arrow below)
  
The ports and integration line should look like:

Fig. 008

• Next, set up the analysis
  
• MenuBar::HFSS::AnalysisSetup::AddSolutionSetup
  
• select the  General tab and set
• SolutionFrequency 12 GHz, leaving other defaults,
• click OK
• If the project manager is invisible (blue arrows below), use MenuBar::View::ProjectManager
• Then in the projectManager pane at the left of the window
• Right-click the Analysis::Setup1 item in projectManager under your project, and select AddFrequencySweep
• Setting
  
• SweepType: Discrete
  
• Start: 6.0 GHz
• End: 12.0 GHz
  
• 25 steps
  
• Your analysis and sweep should appear in the ProjectManager pane (blue arrow below), where the sweep properties should appear when the Sweep item is highlighted
  
• Save your work, MenuBar::File::Save

Fig 009

• Run the simulation
• Make sure the message and progress panes at the bottom are visible by MenuBar::View::MessageManager and MenuBar::View::Progress
• Run the simulation by selecting the SimulationTab (red arrow below), and clicking AnalyzeAll (magenta arrow below)

Fig. 010

• Click ShowProgress and showMessages at the bottom of the window
  
• Watch for any errors at the bottom message areas 
  
• 
  
• To see the results, run right-click Results (red circle below) select CreateModalSolutionDataReport::RectangularPlot (red arrows below)
• In the popup, select Sparameters::s21::dB (blue arrows below) and click newReport (blue circle below)
  

Fig. 011

• You should see your s21 plot as below

Fig 012

• To plot the results you may need to click a minimize icon to show plots/reports hidden behind the top plot/report
• Adjust your plot to go from -50 to 10 dB by double-clicking the y axis,  and double click the lines and make the width=3
  
• Make sure that the legend does not obscure any portion of your plotted curves (move it as above). 
  
• Based on the dimensions of the waveguide, what size waveguide is this (i.e., wr22,wr51,etc?   Hint http://en.wikipedia.org/wiki/Waveguide_(electromagnetism)
  
• What is the theoretical cutoff frequency of the lowest-order mode for the waveguide? 
  
• At what frequency do you observe that S21 is approximately 14 dB below its maximum value? 
  

Part 3: Microstrip

• Microstrip
  
• Compute the impedance of a microstrip line using ADS::ToolsLinecalc
• Use an FR-4 pc-board dielectric and a board thickness of 1mm and line width of 2 mm and length 5 cm
• NOTE: mils are 0.001 inch unit and are not millimeters (mm)
• You may assume 1-ounce copper clad board to determine thickness of metal
  
• Use linecalc tool to compute the impedance and electrical length of the line at 1GHz as illustrated below. 
  
• Note that the MSub component in the schematic specifies the thickness and dielectric constant of the substrate.

Make sure to change the "Er" dielectric constant to the appropriate value (Er is defined in the MSub component on schematic)

Make sure to change the "H" dielectric height/thickness to the appropriate value (H is defined in the MSub component on schematic)

Make sure to change the "W" width to the appropriate value (the width is defined in the MLIN component on schematic)

Make sure to change the "L" length to the appropriate value (the length is defined in the MLIN component on schematic)


• 

• 
  
• Press the "Analyze button, and you should see a result for the transmission line impedance of near 50 ohms (approx 52.2)
• In linecalc, change the width of the line slightly, until you find the proper width for a 50-ohm line
• Copy the linecalc window and save it for future reference For snapshots use the Linux menu Graphice::Ksnapshot
• End of optional exercise

Save your work before exiting

• Exit the program, File->Exit.









Report Data


• ============================    WARNING !!    ====================================
  
• **** WARNING **** YOU MUST USE THE PROJECT REPORT TEMPLATE Below:
• See the Project Report Template at bottom of this page
  
• A well-written report/paper is EXPECTED
  
• STRONGLY RECOMMEND that you read IEEE authorship series: How to Write for Technical Periodicals & Conferences
• Clearly describe everything, including:
• variables in block diagrams
• variables in formulas
• units of variables kHz, pF, nH, m, s,
  
• all traces on plots
• all curves on plots
• all results in any tables
  
• Minimum required data content for your report and demos
• Required theory/formulas numbered as below:
• Characteristic impedance of a parallel -plate waveguide in TEM mode
  
• Required figures:
• Any illegible plots receive zero credit (must be able to read all numbers, axes, labels, curves, grids, titles, legends)
• All plots must of professional quality as in IEEE papers
  
1.  LEGIBLE HFSS 3D plot of parallel-plate waveguide with appropriate caption, as in the red box of Fig 002 above
2. LEGIBLE HFSS plot of parallel-plate waveguide S21 magnitude and phase in degrees from 0 to 2 GHz, as in the yellow box of Fig 002 above
   
3.  LEGIBLE HFSS 3D plot of waveguide similar to right panel of Fig 009, showing at least one waveport with appropriate caption. 
4. LEGIBLE HFSS plot of waveguide S21 dB from 6 to 12.0 GHz, similar to upper right panel of Fig 012
   
5.  LEGIBLE snapshot of linecalc as in Fig. 013 above, for your final microstrip design
   
• Required tabular data content:
1. Table of parallel-plate waveguide impedance:   3 columns,: parameter, value, units
   
• Row 1: width
• Row 2: dielectric thickness
  
• Row 3: relative permittivity of dielectric
• Row 4: theoretical impedance of parallel-plate wavegide TEM mode
• Row 5: simulated impedance of parallel-plate wavegide TEM mode as in Fig 003 above
  
2. Table of microstrip impedance:   3 columns,: parameter, value, units
   
• Row 1: width
• Row 2: board thickness
  
• Row 3: relative permittivity of pc board
• Row 4: impedance of microstrip

• See report template below




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NOTE ReportTemplate: Use the Project Report Template 

  YOU MUST ADD CAPTIONS AND FIGURE NUMBERS TO ALL FIGURES!! 

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Copyright © 2010-2018 T. Weldon


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