1 Installing SuperNEC

SuperNEC is installed by running the setup.exe file from the SuperNEC CD. The installation program performs the following tasks :

· Copies all relevant files to the installation directory. This includes selecting the correct files for the Matlab version you are running and selecting the best engine for your computer architecture.

· Sets the following registry entries

\HKEY_LOCAL_MACHINE\SOFTWARE\PVM_ROOT = SNECROOTV2\pvm

\HKEY_LOCAL_MACHINE\SOFTWARE\PVM_ARCH = WIN32

\HKEY_LOCAL_MACHINE\SOFTWARE\PVM_TMP = c:\temp

· Sets the following environment variables :

SNECROOTV2 = installation directory (for example, c:\snec)

LM_LICENSE_FILE = the license file for SuperNEC (for example, c:\snec\license\license.dat)

TEMP = c:\temp

· Creates the temporary directory (if it does not already exist).

· Adds the SNECROOTV2\bin directory to the path

· Creates a file called startup.m in the SNECROOTV2\matlab directory.

This file is the first file that Matlab executes when you start SuperNEC. It sets up the Matlab path for SuperNEC and calls the structure editor (snecin). An example of the text held in this file is as follows :

path ('c:\apps\snec_24\matlab\input\editor',path)

path ('c:\apps\snec_24\matlab\input\primitive',path)

path ('c:\apps\snec_24\matlab\input\assembly',path)

path ('c:\apps\snec_24\matlab\input\assembly\structures',path)

path ('c:\apps\snec_24\matlab\input\convert',path)

path ('c:\apps\snec_24\matlab\input\assembly\protected',path)

path ('c:\apps\snec_24\matlab\output',path)

path ('c:\apps\snec_24\matlab\utils',path)

path ('c:\apps\snec_24\matlab\ga',path)

snecin

· Installs the dongle drivers (if requested).

If the installation program fails to perform any of the above tasks, then most of them may be completed manually. The only steps that must be performed by the installation package are the copying of the SuperNEC files to the disk and the installation of the dongle drivers.

2 Getting a SuperNEC license

SuperNEC will not run without a valid license. To get a license, run the SuperNEC license tool program (lictool.exe) program. Once you have filled in the required information, either allow the tool to automatically send us an e-mail, or save the information to a text file and attach to an e-mail to supernec@poynting.co.za, with the subject line “request for SuperNEC license”.

A text file will be emailed to you. The text file will look similar to the following:

# Place this file in your INSTALL_DIR\license directory

PACKAGE supernec poynting 1.000 C668CFAAE053 COMPONENTS="snec snres \

sncheck snsig snecrt sig sngui asep" ck=160

FEATURE supernec poynting 1.000 1-dec-2000 uncounted F45F5E68213C \

HOSTID=0000e8e79961 ck=186

The components line may differ depending on the features of your package.

To install your license file, make sure you have SuperNEC installed and have restarted your machine after the installation.

Open the SuperNEC license tool (lictool.exe) and drag and drop the e-mailed license file over the specifed area of the license tool.

If you wish to install the license file manually, you can do so by placing your license.dat file in the SNECROOTV2\license directory (where SNECROOTV2 is your SuperNEC installation directory eg. C:\snec).

Once you have successfully installed the software and the license file you are ready to run SuperNEC.

3 Setting up the Flex license manager

If you have requested a floating license for SuperNEC, then you have to run the Flex license manager on the server machine. If you do not have a floating license then you do not need to run the Flex license manager. A typical floating license is shown below. It differs from the standard license in that it has the additional SEVER and DAEMON lines.

# Place this file in your INSTALL_DIR\license directory

SERVER Maxwell INTERNET=146.141.16.189

DAEMON poynting

PACKAGE supernec poynting 1.000 2F13179D1E32 COMPONENTS="snec snecrt \

snres sncheck snsig sngui asep sig" ck=79

FEATURE supernec poynting 1.000 1-dec-2000 4 5C9154285BFF \

HOSTID="00a0c99068f0 00a0c9d54a9a 00a0c9b6376d 00d0b715cf13 \

00a0c94234a0 0000e80d8647 00a0c942ef18 00a0c9a00614 \

0080ad500a53 00d0b715cf59 000044056957 00d0b715cf11 \

00d0b749c296 00d0b7499cf2 00d0b749b9ab 00a0c942ef18 \

0000e82e130f" ck=113

FEATURE snecslave poynting 1.000 1-dec-2000 4 01B2EABD1156 ck=76

The server machine is identified by name and internet address on the SERVER line of the license file. The server machine for the above license is Maxwell (IP = 146.141.16.189). The Flex license manager must therefore be run on Maxwell.

To set up the Flex license manager you first need to open the control panel. This is achieved by selecting the Start | Settings | Control Panel menu item as shown in Figure 1.

Figure 1 : Opening the control panel.

The control panel, with the Flex license manager highlighted, is shown in Figure 2.

Figure 2 : The control panel.

Open the Flex license manager by double clicking on its icon. A dialog similar to that shown in Figure 3 will appear.

Figure 3 : The Flex license manager.

Click on the ‘Setup’ tab.

Figure 4 : The setup panel for Flex.

Enter the complete path and name of the lmgrd.exe executable in the first edit box. This file will be found in the license directory of SuperNEC.

Enter the name of your flex license file in the second edit box.

Enter the name of license log file in the third edit box.

Check the ‘Start Server at Power-Up’ and ‘Use NT Services’ check boxes if you wish to use these features. This is recommended because you will otherwise have to start the license manager manually every time the computer is shut down.

Once you have successfully entered all the required data, push the ‘Control’ tab. You will be asked whether you wish to save your settings, to which you should answer yes. The control panel is shown in Figure 5.

Figure 5 : The Flex license manager control panel.

To start the license manager, push the Start button. The text ‘Server Started’ should appear below the ‘Status’ button.

Note : The SYSTEM must have full rights to the directory that holds the license.dat file. To check that this is the case, check the permissions of the SuperNEC license directory. The permissions should at least have the line highlighted in Figure 6.

Figure 6 : The permissions of the SuperNEC license directory.

You can check that the license manager has started successfully by opening up the task manager and identifying lmgrd.exe and poynting.exe processes. Figure 7 shows the task manager with the poynting.exe process highlighted and 7 processes below it you can see the lmgrd.exe process. This indicates that the license manager has been successfully started.

Figure 7 : The task manager.

Note : If you are already using the Flex license manager for another application on your machine, then you can combine the two license files. This is achieved by appending the entire contents of the SuperNEC license file to the license file of the other package. You can then restart the Flex license manager with the modified license file.

4 A brief SuperNEC tutorial

This section gives you a brief introduction to using SuperNEC. It attempts to give you an indication of what is involved in setting up and running a simulation. For detailed instruction, you are referred to the SuperNEC HTML or Word document files.

4.1 Running SuperNEC

To start the SuperNEC program use the Start | Programs | SuperNEC | SuperNEC menu item as shown in Figure 8.

Figure 8 : Starting SuperNEC.

The Matlab window and the SuperNEC structure editor will appear for users that have Matlab, otherwise only the SuperNEC structure editor will be displayed (assuming you have installed a valid license). This is shown in Figure 9.

Figure 9 : The SuperNEC and Matlab windows.

4.2 Accessing the SuperNEC documentation

There are two SuperNEC directories that contain help files. The SNECROOTV2\doc directory holds the Word-2000 documentation for the program and the SNECROOTV2\html directory holds HTML versions of the same files. Thus, if you do not have access to Word-2000, you can still view the documentation using a web browser.

On most SuperNEC dialog boxes there is a small button with a question mark. When you push this button, Matlab will attempt to start your web browser. If successful, then browser will open the relevant document at the page that covers the dialog box in question.

If Matlab is unable to start your web browser, then you can start the web browser yourself and then push the SuperNEC help button. Matlab will then attempt to find the browser and display the relevant page.

If this does not work, then you may have to upgrade your web browser. For example, old versions of Internet Explorer (versions 4.0 and older) do not support the web page addressing scheme used by SuperNEC and hence will not be able to load the HTML file at the correct page. In fact Internet Explorer version 3.0 will not even open the HTML file, let alone at the correct page. Internet Explorer version 5.0 is the recommended browser.

Netscape version 4.5 recognises the addressing scheme but loads the help file every time a help button is pushed. This can be very time consuming as the HTML files can take quite some time to load. Later versions of Netscape may perform a little more intelligently. It is not know whether earlier versions of Netscape will work correctly.

If the on-line help fails, you can always open the HTML file manually and use the table of contents to navigate about the file.

The documents in the HTML and doc directories are as follows :

· sngaurm – The Genetic Algorithm (GA) Optimiser Reference Manual. This manual documents the use of the GA optimiser from the Graphical Interface and Matlab® command line.

· snguitut – This document.

· snguiirm – The input reference manual. This manual documents the structure editor and all aspects regarding the generation and simulation of SuperNEC models.

· snguiorm – The output reference manual. This documents the SuperNEC file parser and all the output graphical utilities available in SuperNEC.

· snmomurm – The command line reference to the SuperNEC engine. This manual documents the construction of a SuperNEC input file for the engine. This manual is only required if you want to manually construct your own SuperNEC input files (i.e., without using the structure editor).

· snparurm – The manual that documents the setting up of the parallel SuperNEC for Windows machines.

· snutdtrm – The technical documentation for the UTD aspects of the SuperNEC code.

· snmomtrm – The SuperNEC technical reference manual which documents the MoM theory used in the code.

4.3 Modelling an array of modified Yagi antennas using SuperNEC

The starting point for this tutorial is the Yagi antenna. SuperNEC has a number of built-in antennas that can be very easily constructed. These antenna assemblies are listed in the menu item Add | Assembly | antennas as shown in Figure 10. To add a Yagi antenna to the structure, select the menu item Add | Assembly | antennas | snyagi.

Figure 10 : Adding a Yagi to the structure.

A dialog box requesting the parameters of the Yagi will appear (Figure 11).

Figure 11 : Entering the Yagi parameters.

The main parameters of the Yagi are the element spacing, element lengths and the radii of the wires making up the Yagi. The above dialog shows the default settings for a Yagi, which is a Yagi with 5 elements each spaced 0.2 m apart. On pushing the OK button, a segmented Yagi will appear in the structure editor.

Figure 12 : The default SuperNEC Yagi.

Notice that the second element has a yellow marker on its centre segment. This marker is the SuperNEC symbol for a source.

SuperNEC provides both zooming and panning functionality. To zoom in on the structure do the following :

· Push the shift key on the keyboard.

· Position the mouse pointer within the grid displaying the structure, but not over any part of the structure.

· Push the left mouse button and move the mouse away from you. This will invoke the zoom-in facility.

· Moving the mouse towards you will give you the effect of zooming out.

To pan the view of the structure :

· Push the control key on the keyboard.

· Position the mouse as was done for zooming.

· Mouse the mouse to the left, right, up or down to pan the view.

On the bottom left hand side of the structure editor window is the text ‘Model Freq :’. The number to the right of this text specifies the frequency at which the structure is modelled. In this case, it is set to 300 MHz. You can change this figure to generate a model of the antenna at a different frequency. Try changing the number to 400 and then push the ‘Set’ button. Note that the number of segments used to model the antenna increases.

The ‘Group Level’ setting for the model is currently set to high. Reduce the level to 2 by clicking on the button with the ‘<’ label. Now use the mouse to select part of the structure (left click whilst the mouse pointer sits on top of part of the structure). Note that you are able to select individual the wires making up the structure. Reduce the group level to ‘low’ and again select part of the structure. You are now able to select the individual segments.

Select the segment with the source attached and push the ‘Edit’ button. A dialog box for editing the segment will appear as shown in Figure 13.

Figure 13 : The segment edit box.

Note that this segment is excited with an applied field voltage source with a value 1+0i. Now cancel the edit box.

You can also edit the segment by double clicking on the segment in the structure editor.

Now increase the group level setting, select the last wire element of the antenna and push the ‘Edit’ button (or double click on the last element). The edit box for the subassembly ‘snwire’ appears. You can now change the length (or some other parameter) of the wire by changing the values in the edit box.

If you increase the group level back to high and double click on the structure, the edit box for the Yagi antenna will appear. If you push the OK button, then the Yagi will be regenerated and any changes that you have made to the elements of the Yagi will be lost.

Let us now assume that we want to connect the centre of the last two elements of the Yagi with a 45 W transmission line. This is achieved as follows :

1. Set the group level to ‘low’ so that we are able to select individual segments.

2. Left click on the centre segment of the last element of the Yagi (this should highlight the segment in red).

3. Hold the shift key down and left click on the centre segment of the second last element of the Yagi (you should now have two segments highlighted in red as shown in Figure 14).

Figure 14 : Selecting two segments in the model.

4. Select the menu item Add | Primitive | Network | Transmission Line as shown in Figure 15.

Figure 15 : Adding a transmission line between the two highlighted segments.

5. The transmission line dialog box will appear. Fill it in as shown in Figure 16.

Figure 16 : Setting the properties of the transmission line.

6. Push the OK button and another dialog asking how the segments should be linked will be displayed.

Figure 17 : How should the segments be linked.

7. Push the ‘Pairs’ button and the transmission line will be added to the structure as shown in Figure 18.

Figure 18 : The new transmission line.

You can edit the parameters of the transmission line by double clicking on the centre portion of the transmission line symbol.

We will now put a lumped element load of 3 W onto the tips of reflector element. This is achieved as follows :

1. Select the two segments as shown below:

Figure 19 : Selecting the segments to load.

2. Call the menu item Add | Primitive | Load.

Figure 20 : Illustrating the menu item for adding a load.

3. Fill in the parameters of the load.

Figure 21 : Adding a 3 W load

4. Push the OK button.

Figure 22 : The Yagi with two 3 W loads applied.

Note that the SuperNEC symbol for a load is a black mark as shown in Figure 22.

You can check the loading of parameters of each of the segments by double clicking on the loaded segments. The segment edit box for the left hand segment should look similar to Figure 23.

Figure 23 : Illustrating the settings for one of the loaded segments.

We will now illustrate some of the other structure manipulation features of the editor. First we will translate the entire structure 1 m in the x-direction and 1 m in the z-direction. To do this :

· Push the ‘Select All’ button at the bottom of the structure editor window.

· Push the ‘Translate’ button and fill in the resulting dialog box as follows :

Figure 24 : Translating the structure by the vector [1, 0, 1].

· Push the OK button and the structure is translated.

Figure 25 : The translated structure.

We will now create a stacked array of these Yagi’s. The stack will be vertically oriented and the spacing between antennas will be 0.5 m. To do this :

· Select all.

· Push the translate button and fill in the resulting dialog box as follows :

Figure 26 : Creating 2 duplicates of the structure.

· Push the OK button and observe the result.

Figure 27 : A 3-stack of Yagi’s.

We will now assume that this modification we made to the structure was incorrect. To undo this modification push <control-Z> (the control key and then the Z key).

To redo the operation push <control-Y>. The structure should now be restored to that shown in Figure 27.

The structure will now be reflected along the x-axis (y-z plane). To do this :

· Select all.

· Push the reflect button and check the x-axis check box.

· Push the OK button.

Figure 28 : The structure reflected along the x-axis.

Note that the reflected portion of the structure is grey. This grey colour means that these elements of the structure form an image of the original structure and that symmetry will be used in the simulation. If you modify the structure (other than to add transmission lines and excitations), then the symmetry of the model will be lost.

This concludes the generation of the model.

4.3.1 Setting the simulation settings

Let us assume that we wish to model this structure from 250 MHz to 300 MHz and determine its radiation pattern in this frequency range. To set these simulation settings call the Edit | Simulation Settings menu item.

Figure 29 : Calling the simulation settings editor.

Figure 30 shows the simulation settings editor with the simulation frequencies set to start at 250 MHz, end at 300 MHz and go up in 10 MHz intervals ([250:10:300]).

Figure 30 : Setting the simulation frequency range.

To set the radiation patterns, click on the last line of the summary list box (Radiation Patterns: <click here to add>). The bottom part of the dialog box changes to the radiation pattern editor as shown in Figure 31

Figure 31 : The radiation pattern editor.

Select the 3D pattern in 4 degree increments from the predefined patterns list box and push the Add button. The simulation settings dialog changes to that shown in Figure 32.

Figure 32 : Adding a radiation pattern.

This concludes the simulation settings requirement of the simulation and the OK button can be pushed.

You now return to the structure editor. To simulate the structure, push the simulate button at the bottom right hand side of the editor. You will be requested to save your work, after which the simulation will proceed. The simulation takes place in a DOS box similar to Figure 33.

Figure 33 : Running the simulation in a DOS window.

To view the simulation results, use the Simulate | View Output menu item.

Figure 34 : Starting the output viewer.

The output viewer as shown in Figure 35 will appear.

Figure 35 : The output viewer.

Push the ‘All’ button below the ‘Filter Available Structures’ list box and also the ‘All’ button below the ‘Filter Available Frequencies’ list box. The ‘Summary of available results’ list box will change as shown in Figure 36.

Figure 36 : Showing the available currents and charges for display.

The top line of the list box is highlighted. This corresponds to selecting all the current distributions for plotting. To see these current distributions push the ‘Plot’ button. A window similar to Figure 37 will appear.

Figure 37 : The current distribution.

The slider at the bottom right-hand side of the screen can be moved to view the currents at the other simulation frequencies.

Return to the output viewer and push the ‘Radiation Pattern’ tab at the top of the viewer. The ‘Summary of available results’ list box will change as shown in Figure 38

Figure 38 : Showing available radiation patterns.

Tick the check box labelled ‘Structure’ at the bottom left hand side of the window. If the ‘Plot’ button is now pushed, then the radiation patterns overlaid on the structure will be plotted. This is illustrated in Figure 39.

Figure 39 : The radiation pattern and Yagi antenna.

The structure had to be magnified in order to see it properly. This was achieved using the View | Structure | Scale menu item.

The slider at the bottom right-hand side of the plotter can be moved to show the radiation pattern at different frequencies.

This concludes the modified Yagi array tutorial. The structure file, SuperNEC input and output files can be found in the tutorial directory. They are called iptut.str, iptut.nec and iptut.out respectively.

There are a number of other example files located in the tutorial directory. They are :

1. The files optut.* model a folded dipole Yagi antenna from 100 MHz to 300 MHz. Near fields, 2-D radiation patterns and 3-D patterns are computed for this antenna.

2. The files optutmom.* model a monopole on a finite size ground plate. The ground plate is modelled using MoM and 2-D radiation patterns are computed.

3. The files optututd.* model a monopole on the same size finite ground plate as the optutmom.* simulation. The radiation patterns requested are also identical.

You can compare the results obtained from the MoM and UTD monopole simulations as follows :

· Start the output SuperNEC utility by typing snecout at the Matlab command line.

· Load the optutmom.out file into the output utility.

· Push the ‘Load’ button and load the optututd.out file.

Figure 40 : The SuperNEC output interface with both MoM and UTD output files loaded.

· Push both ‘All’ buttons to select both models and all frequencies.

· Push the ‘Radiation Pattern’ tag and select the 250 MHz radiation patterns as shown below :

Figure 41 : Selecting the 250 MHz radiation patterns.

· Check the ‘Overlay’ check box and push the ‘Plot’ button. The radiation patterns will appear overlaid in the radiation pattern viewer as shown in Figure 42.

Figure 42 : Comparing the MoM and UTD patterns.

· Normalise the radiation patterns as shown below :

Figure 43 : Normalising the radiation patterns.

· Compare the normalised radiation patterns at the other frequencies in a similar manner.

· The input impedances computed using the two techniques can be compared by setting the output interface as follows :

Figure 44 : Setting up the output interface for a comparison of input impedances.

· Check the ‘Overlay’ button and push the ‘Plot’ button. The input impedances are overlaid on the Smith chart as shown in Figure 45.

Figure 45 : Comparing the input impedance as computed by the two methods.

4.4 Running SuperNEC from the Matlab command line

The SuperNEC structure editor, engine and output unit can all be run from the Matlab command line. To illustrate this process, three demonstration m-files have been written. They are to be found in the tutorial directory and are called demo1.m, demo2.m and demo3.m.

The file demo1.m computes the resonant length of a monopole mounted on an infinite ground plane. It does this by systematically varying the length of the monopole until the imaginary part of the impedance is close to zero. The algorithm is extremely crude, but serves to illustrate some basic concepts.

To run the demo1.m file :

· At the Matlab command line use the cd command to change to the tutorial directory. For example, cd c:\snec\tutorial.

· Run the demo1.m file by typing demo1 at the Matlab command line.

The demonstration draws the monopole in the structure editor window for each step in the simulation so you should be able to see the change in the length of the monopole as the simulation progresses. The results of the simulation are printed at the Matlab command line at the end of the simulation. You can view the m-file code by typing ‘edit demo1.m’ at the Matlab command line.

The second demonstration file illustrates the use of symmetry in the simulation of two back-to-back Yagi antennas. The distance between the antennas is varied between 0.1 m and 1.5 m in increments of 0.05 m. At each step in the simulation, the structure is simulated and the maximum gain from the radiation pattern is extracted. The code finds the separation that gives the maximum gain in any direction (it gives no regard to other attributes of the pattern). At the end of the simulation, the variation of maximum gain and separation is plotted and, in addition, the ‘best’ radiation pattern is plotted.

The last demonstration m-file illustrates some of the SuperNEC command line functionality. When you run this file, watch the Matlab command line for the steps that the m-file is performing. It asks you to push a key before each command is carried out.

5 Frequently asked questions

How can I get a copy of the SuperNEC software?

SuperNEC can be downloaded over the internet from www.supernec.com or if you are unable to download it we can send you a CD of the latest version of the software.

Q. How can I receive a license for the software?

A. In order for us to issue a license you must first send us your machine's "hostid." In order to get your “hostid” :

Run the "License Tool" programme that comes with SuperNEC (lictool.exe), and fill in the required fields.

Choose either the E-MAIL NOW option, which will automatically send us the required information or the SAVE AS TEXT AND E_MAIL LATER OPTION and attach the saved file to an e-mail to supernec@poynting.co.za. Once you have done this, we will generate a license file unique to your machine, which we will send to you as soon as possible.

Q. How do I install the license.dat file?

A. Either drag and drop the license.dat file over the specified area of the SuperNEC license tool program (lictool.exe) or copy the license.dat file that we have sent to you to "INSTALL_DIR\license\"

directory, where INSTALL_DIR is the SuperNEC installation directory eg. c:\snec\.

Q. I have installed the license file, but I still receive errors when I try to run the software.

Check that the license file (license.dat) that was sent to you has been copied to the snecroot\license directory and not to another directory. Also check that if you selected the “matlab runtime” option that you have a SuperNEC runtime license. Evaluation licenses usually include a runtime license, free academic SuperNEC Lite licenses do not.

Q. What requirements do I have to meet to get a license for the free SuperNEC?

A. If you are affiliated to an academic institution (i.e. you are a student or lecturer) you qualify for a free copy of SuperNEC lite.

Q. Does the free version of SuperNEC have all the functionality of the full version of SuperNEC?

The free version of SuperNEC has all the functionality of the full version, but is limited in the size of the problems that can be solved. (i.e. problems less than 300 segments and not more than 3 UTD objects can be used in a model).

Q. When I run the software the parameters dialog box in the GUI does not appear.

A. We are aware that there is a compatibility problem with some versions of Matlab and Windows XP. You can go to www.mathworks.com/support/solutions/data/30479.shtml to find the fix for this compatibility problem.

Q. Can I run SuperNEC without Matlab?

A. Yes, you can run SuperNEC without Matlab. This is known as the run-time version of SuperNEC. Please make sure that you select the Matlab runtime option during the installation process.

Q. What is the difference between the run-time and normal versions of SuperNEC?

A. The run-time version of SuperNEC does not require Matlab. This does however prevent the user from creating his or her own assemblies.

Q. What is SIG?

A. SIG stands for Structure Interpolation and Gridding. SIG is a stand-alone program that enables users to create complex models, such as aircrafts for NEC type programs.

Q. Can I load Autocad files(*.dwg) into SuperNEC?

A. SuperNEC does not currently support files with the *.dwg file extensions.

Q. If the IP address of my computer changes will this affect my SuperNEC license?

A. No, this will not affect your SuperNEC license.

Q. I have formatted the hard drive of my computer, why does my SuperNEC

software not work anymore?

A. The unique license file was generated for your computer using your Ethernet address or hard drive key. Once your hard drive is formatted, the key changes. You may need to obtain a new license file from us.