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.

  1. Create a dielectric medium.
    • Label: RogersDuroid5870
    • Relative permittivity: 2.2
    • Dielectric loss tangent: 0.0012
  2. Add a planar multilayer substrate (infinite plane) with a conducting layer at the bottom.
    1. Select Plane / Ground.
      • Click Planar multilayer substrate.
      • Thickness (Layer 1): 2.5e-3
      • Medium (Layer 1): RogersDuroid5870
      • Ground plane (Layer 1): PEC
      • Z value at the top of layer 1: 0.
  3. Create the branch coupler.
    1. Import the Parasolid model from file.
      Tip: On the Home tab, select Import and select Geometry. Browse for the feedNetwork.x_b Parasolid file.
  4. Create four microstrip ports on the four terminals of the network. Number the ports sequentially in an anti-clockwise manner.



Figure 1. 3D view of the feed network showing the port numbering.

  1. Add a 120 Ω load on MicrostripPort4.
  2. Set the frequency.
    • Continuous interpolated range
    • Start frequency (Hz): 0.8*2.4e9
    • End frequency (Hz): 1.2*2.4e9
    • On the Export tab check the Specify number of samples for exported data check box and enter a value of 100.
      Note: The setting ensures that the exported Touchstone file contains 100 frequency samples.