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 the following variables.
    • freq = 1.654e9 (The operating frequency.)
    • lambda = c0/freq (The wavelength in free space.)
    • n = 10 (number of turns for the helix.)
    • helix_alpha = 13 (pitch angle of the helix.)
    • helix_radius = lambda*cos(helix_alpha*pi/180)/pi/2 (radius of the helix.)
    • plate_radius = 0.75*lambda (radius of the ground plate.)
    • wire_radius = 0.65e-3 (radius of the helix wire segments.)
  2. Create the circular base plate of the helix.
    1. Create an ellipse.
      • Centre point: (0, 0, 0)
      • Radius (U): plate_radius
      • Radius (V): plate_radius
  3. Create the helix
    • Definition method: Base centre, radius, pitch angle, turns
    • Origin: (0, 0, 0)
    • Radius: helix_radius
    • Pitch angle: helix_alpha
    • Number of turns: n
  4. Union the helix and ellipse.
  5. Add a wire port (segment) to the base of the line.
  6. Add a voltage source to the port. (1 V, 0°, 50 Ω).
  7. Set the frequency to freq