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. Set the model unit to millimeters.
  2. Define the following variables:
    • a1 = 15.8 (width of Ku section.)
    • b1 = 7.9 (height of Ku section.)
    • l1 = 12 (length of Ku section.)
    • a2 = 22.9 (width of X section.)
    • b2 = 10.2 (height of X section.)
    • l2 = 12 (length of X section.)
    • fmin = 9.4872e9 (minimum calculation frequency.)
    • fmax = 15e9 (maximum calculation frequency.)
    Note: fmin is just above the cutoff frequency for the Ku band waveguide section.
  3. Create the Ku band section.
    1. Create a cuboid
      • Base corner (C): (-a1/2, -l1, -b1/2)
      • Width (W): a1
      • Depth (D): l1
      • Height (H): b1
      • Label: Ku_band_wguide
  4. Create the X band section.
    1. Create a cuboid.
      • Base corner (C): (-a2/2, 0, -b2/2)
      • Width (W): a2
      • Depth (D): l2
      • Height (H): b2
      • Label: X_band_wguide
  5. Union both cuboids.
  6. Set the both regions to free space.
    Tip: Free space changes the region from solid PEC to vacuum.
  7. Simplify the part with the simplify tool.
    Tip: The simplify tool removes the face at the junction between the two cuboids. Alternately, use face selection to delete this face.
  8. Rename the face at the end of the Ku band section to Port1 and at the X band section to Port2.
  9. Add waveguide ports to the faces with labels Port1 and Port2.
    Tip: For accurate phase results set the reference vector with the same orientation for both ports. This is not required for the magnitude.
  10. Check that the propagation direction of each port is set inwards.
  11. Set the frequency.
    • Continuous interpolated range.
    • Start frequency (Hz): fmin
    • End frequency (Hz): fmax
    Tip: Set symmetry to save computational resources.