Where To Find This Example
AWR Version 14
AWR Version 13
MDIF Data Files
The AWR Design Environment (AWRDE) can read Microwave Data Interface Files (MDIF) . MDIF file format allows data to be sorted by unlimited number of independent variables.
Two test cases are shown.
1. mdif two indep variables schematic - a two dimensional MDIF that shows FET s-parameters and noise vs. frequency vs. gate voltage.
2. mdif three indep variables schematic - a three dimensional MDIF that shows FET s-parameters and noise vs. frequency vs. gate voltage vs. drain voltage.
Each one of these schematics sets the MDIF file parameters to a swept variable to display all of the contents of the MDIF files. You will see on each graph that it is displaying multiple traces, due to the swept variable settings.
In this project two methods of using an MDIF data file are shown. First we see how simple it is to view the data before the MDIF data is used in any complex simulations. Next we see how the MDIF data file is added to a schematic and used for such simulations.
The Data Files tab in the Project Options of the AWR Design Environment dialog box offers sorting options for imported/linked MDIF files. The options are Same as File, Alphabetical and Alphanumeric. Same as file, the default option, causes the sorting order to be the same as the (often arbitrary) ordering of values in the MDIF file.
Description of the schematics
1. The schematic “mdif two indep variables” uses a two dimensional MDIF file that shows FET s-parameters and noise vs. frequency vs. gate voltage.
2. The schematic “mdif three indep variables” uses a three dimensional MDIF file that shows FET s-parameters and noise vs. frequency vs. gate voltage vs. drain voltage.
Each of these schematics sets the MDIF file parameters to a swept variable to display all of the contents of the MDIF files. You will see on the "NF mdif three indep variables" and "NF mdif two indep variables" graphs that they are displaying multiple traces, due to the swept variable settings.
1. MDIF files are imported using the same steps as any other data file.
2. When you place an MDIF file in a schematic, the parameters in the MDIF file will be exposed at model parameters for the subcircuit. For the model parameters, you will only be able to set discrete values.
3. You can set these parameters to a variable. Since the parameters are setup as "enumerated" values, you need to treat the variable like integer values. So if I set a parameter to a variable "x" and set x=0, then it will pick the first data block, "x=1", the second data block and so on.
4. In this example, the parameters are set to variables and swept variable blocks are used. This is the method to use if you want to plot all of the data in an MDIF on one graph.
5. The MDIF files can be viewed by double clicking on them under the Data Files section in the Project tab on the left.
6. When using an MDIF in a design, you probably won't sweep each of the settings, but you could tune or optimize these parameters to achieve your design goals.
Things to Try
1. Open up the “mdif two indep variables” schematic and remove the variable from the Vg parameter of the mdif model (highlight and hit delete), disable the SWPVAR block in that schematic, and have the graph “NF mdif two indep variables” visible and open. Once the change is made, you will now only see one trace on the graph. Change the Vg parameter and watch the results change. Then set the Vg parameter to be tunable and use the tuner to change the value and watch the graph results change.
2. Double click on the measurement for the "S21 mdif two indep variables" graph, and along the right of the dialog, you will see a swept variable setting named "Vg". On that dialog, change from Plot all traces to Select with tuner and then open the tuner and watch the results on that graph.