Basic Three step of Any FEM software

I - Insert an HFSS design into a project
1) On the Project menu, click Insert HFSS Design

The new design is listed in the project tree. It is named HFSSDesignn by default, where n is the order in which the design was added to the project. The 3D Modeler window appears to the right of the Project Manager. You can now create the model geometry

II -Selecting the Solution Type

Before you draw the model, specify the design’s solution type.

1) On the HFSS menu, click Solution Type. The Solution Type dialog box appears.

2) Select Driven Modal in the solution types.

We select Driven Modal as our model is a rectangular waveguide and Driven modal is used for calculating the mode-based S-parameters of passive, high-frequency structures such as microstrips, waveguides, and transmission lines, which are “driven” by a source

III- Setting the Model’s Units of Measurement

You can then choose to display the model’s dimensions in the new units, or rescale the model’s dimensions to the new units.

To set the model’s units of measurement:

1.On the 3D Modeler menu, click Units. The Set Model Units dialog box appears
2. Select the new units for the model from the Select units pull-down list.

You can select the Rescale to new units option to rescale the dimensions to the new units. Clear the Rescale to new units option (the default) to convert the dimensions to the new units without changing their scale

3.Click OK to apply the new units to the model