Creating the Model
Create the model in CADFEKO. Define any ports and sources required for the model. Specify the operating frequency or frequency range for the model.
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Import the Parasolid geometry of the car from the file
car_geometry.x_b
Note: The model is included in the Feko installation.
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Rename the three imported parts as follows:
- The structure for the car: car_body.
- The structure for the antenna: antenna.
- The structure for the windscreen: windscreen.
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Union car_body and antenna.
Note: The windscreen curvature reference is not part of the union as it is not required to be electrically connected to the model.
- Add a wire port to the start of the line.
- Add a voltage source to the port. (1 V, 0°, 50 Ω).
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Create a dielectric medium (glass).
- Relative permittivity: 7
- Dielectric loss tangent: 0.03
- Label: glass
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Create a dielectric medium (PVB foil).
- Relative permittivity: 3
- Dielectric loss tangent: 0.05
- Label: pvb_foil
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Create a layered dielectric (2D).
- Label: windscreen_layers
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Layer 1:
- Thickness: 2.1e-3
- Dielectric material: glass
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Layer 2:
- Thickness: 0.76e-3
- Dielectric material: pvb_foil
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Layer 3:
- Thickness: 2.1e-3
- Dielectric material: glass
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Create a windscreen medium.
- Layer definition: windscreen_layers
- Offset L: 2.1e-3 + 0.76e-3
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Label: Windscreen1
Tip: Variable Offset L specifies the reference plane where the windscreen antenna (wires) are located. For this example, the antenna is placed between the two layers, glass and pvb_foil.
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Specify the windscreen curvature reference.
- Select the single face of the windscreen.
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Include the windscreen curvature reference as part of the windscreen
solution.
Note: The windscreen curvature reference is used as part of the windscreen solution to define the shape and position of the windscreen.Tip: Open the Modify Face dialog, click the Solution tab. From the Solution method drop-down list, select Windscreen.
A windscreen curvature reference is displayed semi-transparent in the colour of the windscreen definition. -
Specify the windscreen antenna (wires).
- Select the windscreen antenna wires.
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Include the windscreen antenna as part of the windscreen solution.
Note: Variable Offset A is the distance from the windscreen curvature reference to the windscreen antenna (wires). For this example, set Offset A equal to 0 to place the antenna on the reference plane.Tip: Open the Modify Edge dialog, click the Solution tab. From the Solution method drop-down list, select Windscreen.
Figure 1. 3D view showing the selected windscreen antenna. - Set the continuous frequency range from 90 MHz to 110 MHz.