Parametric Studies

When designing an RF system, running parametric studies is really helpful because it lets you try out different design variables and find the ones that give the best performance. This article will show how to create parametric studies in CENOS : RF using two different approaches:

Import CAD

With this approach, multiple CAD files representing the same geometry but with different dimensions can be imported at once. After loading the files, you only need to define the roles and physics for one of the cases.

When the simulation is run, a separate simulation case will be automatically created for each imported CAD model, allowing the results to be evaluated and compared efficiently.

 

 

CAD editor

By using the integrated CAD editor (FreeCAD), the geometry can be created from scratch and fully parameterized. This allows the values of design variables to be modified easily!

You can define parameters in the Cenos Parameters spreadsheet where you can use various units and/or mathematical equations for the values.

To use these parameters, click the Formula Editor button in the value field and then enter Cenos.Parameters.name.

Once you have finished working on your model and assigned all the parameters you are interested in, you can send the geometry to CENOS, where in the Physics section you will be able to start the parametric study.

Getting the geometry to CENOS

To send your finished geometry to CENOS, you have to:

1. Select all final objects in the tree view.
2. Click Send Geometry to CENOS.

As geometry is being sent to CENOS, the FreeCAD study will be automatically saved in the simulation folder, so you can close it.

How to use Parametric Study?

Once you have sent your geometry to CENOS and are in the Simulation Control, you will need to enable the parametric study and click on CONFIGURE.

The parameters you have previously defined will appear in a new window, you can add one or more parameters! You can also add as many cases as you need to simulate – just click Add and a new case will be created.

When you have finished making the necessary adjustments, you just need to close the parametric study window and continue with the usual workflow.

Limitations​

Geometry overlapping

By changing the parameter values, geometry can become non-physical, i.e. elements can overlap each other or sketches can be left out of a solid surface. It is necessary to avoid these situations so that the simulations work properly and the results are obtained without any inconvenience. Make sure that your geometry has the necessary constraints and that the parameter dimensions are physically possible.

How to access the results of the Parametric Study?

Once your simulation has finished computing, the results will be displayed automatically. You can access the charts for all cases within a single window, allowing you to directly compare the performance of designs with different dimensions.

Similarly, the radiation patterns for all cases can be viewed in 2D, in both polar and cartesian coordinate systems, for each calculated frequency. This setup provides a clear and convenient way to analyze and evaluate the performance of each configuration.

You have the option to switch between combined results and the individual results of each case:

• In the Results window, click on the Switch Results tab to display a list of all computed cases.

• In the upper-left corner, locate the Parametric Study box. Here, you can choose to open either the individual results for each case or the combined results

• Clicking on the Visualization box will take you directly to the combined results view, allowing for a convenient overview and comparison of all cases.