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 Millimetres.
  2. Define the following variables.
    • epsr = 2.62 (The relative permittivity of the substrate.)
    • patch_rad = 17.5 (The radius of the patch.)
    • line_len = 79 (The length of the strip line.)
    • line_width = 4.373 (The width of the strip line.)
    • offset = 0 (The distance between the patch centre and the feed line.)
    • substrate_d = 3.18 (The height of the substrate.)
    • f_min = 2.8e9 (The minimum frequency.)
    • f_max = 3.2e9 (The maximum frequency.)
  3. Create a dielectric medium.
    • Relative permittivity: epsr
    • Dielectric loss tangent: 0
    • Label: substrate
  4. Create the circular patch.
    1. Create an ellipse.
      • Centre point: (0, 0, 0)
      • Radius (U): patch_rad
      • Radius (V): patch_rad
  5. Create the feed line.
    1. Create a rectangle.
      • Definition method: Base corner, width, depth.
      • Base corner: (-line_width/2, 0, -substrate_d/2).
      • Width (W): line_width
      • Depth (D): line_len
  6. Add a planar multilayer substrate (infinite plane) with a conducting layer at the bottom.
    1. Add a Plane / ground.
    • Select Planar multilayer substrate in the drop-down list.
    • Ground plane (Layer 1): PEC
    • Thickness (Layer 1): substrate_d
    • Medium (Layer 1): substrate
  7. Create a microstrip port
    • Click on the short edge (beginning) of the feed line.
      Tip: To select the edge, hide the Plane / ground or add a cutplane.
  8. Add a voltage source to the port. (1 V, 0°, 50 Ω).
  9. Set the frequency.
    • Continuous (interpolated) range
    • Start frequency (Hz): f_min
    • End frequency (Hz): f_max