Skip to main content

Physics and simulation setup

Overview

Setting up the physical settings in CENOS is simple. On the left side you can see the preview window of your geometry.

Preview

On the right you can find the physical definitions of your model. You can switch between the definitions using the tabs. The material definitions are sorted by role, so you will see the volumes and surfaces with the same role under the same tab.

Tabs

Definitions

In Physics the definitions are quite straightforward.

Simulation Control

In Simulation Control you need to select the frequency of your model, choose whether you want to enable Sequential or Simultaneous excitation of the defined ports and enable the Parametric Study. You can set one frequency, or do a frequency sweep to test your model for a whole range of frequencies.

Frequency Selection

Parametric Study

Touchstone export

You have the option to renormalize the port impedance, where you can enter the value of the resistance and reactance. A Touchstone file will be automatically generated and you can select to display this data in Real/imaginary format or using dB and angle.

Touchstone export

You can find the Touchstone file in the folder called "extra_results" located in the general folder of your case (case_folder\extra_results). In this same folder you will find the Smith Chart that you can use as a tool for impedance visualization!

Parametric Study

With CENOS RF software it is possible to create a parameterized model and change the dimensions of your geometry in a simple way.

Without parametric values, each geometry modification requires the creation of a new model from scratch or going back to previous stages of the simulation to make the required changes, which can be very time consuming. If the model is parameterized, geometry modifications only require changing the required parameter in the Simulation Control.

How to use Parametric Study?

The Parametric Study feature is available through the Geometry Editor approach. The first step is to parametrize your geometry within FreeCAD.

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.

Enable Parametric Study

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.

Parametric Study list

Parametric Study list

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.

Overlapping

Overlapping

Volumes

For volume objects of your model you only need to define the material it is made of.

You can write the name of your material directly into search bar, choose from CENOS's built-in material library or define your own material!

Material

You can browse through the whole material library by clicking on Select... and see all the defined materials. If you have defined some new materials, you can see them all in the MY MATERIALS tab.

Material library

Surfaces

The surfaces of your model, which are typically conductive materials, are automatically assigned as perfect electric conductors, but you are able to redefine them as real materials as well, such as copper or aluminum.

Surface material definition

Ports

After you have defined your ports in the Geometry section, you can define the configuration of your ports in the PORTS tab.

Lumped ports

When using discrete ports you can define the input impedance and phase shift angle.

Discrete port

Coaxial port

The coaxial ports in CENOS are defined using one face of the dielectric. You can easily modify the input impedance and phase shift angle.

Coaxial port

Waveguide port

In the waveguide ports you can change the port number and select the Mode you will use.

Waveguide port

note

When using multiple ports don't forget to number each one with a different number sequentially, starting at number 1. If there are ports with the same port number this will cause problems!

Number port

Number port

Lumped elements

If you have defined some lumped elements in your model, you can define the resistance, capacitance and/or inductance for each element in the Lumped Elements tab. Here you can also switch the configuration of each element between Serial and Parallel.

Lumped Elements