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. Define the following variables:
    • freq = 1e9 (The operating frequency.)
    • lambda = c0/freq (The wavelength in free space.)
    • L0 = 0.2375 (Length of the reflector element in wavelengths.)
    • L1 = 0.2265 (Length of the driven element in wavelengths.)
    • L2 = 0.2230 (Length of the first director in wavelengths.)
    • L3 = 0.2230 (Length of the second director in wavelengths.)
    • S0 = 0.3 (Distance between the reflector and driven element in wavelengths.)
    • S1 = 0.3 (Distance between the driven element and the first director in wavelengths.)
    • S2 = 0.3 (Distance between the two directors in wavelengths.)
    • r = 1e-4 (Wire radius.)
  2. Set the incident power for the 50 Ω transmission line to 1 W.
  3. Create the dipole (driven element) in the Yagi-Uda antenna.
    1. Create a line.
      • Start point: (0, 0, -L1*lambda)
      • End point: (0, 0, L1*lambda)
      • Label: activeElement
    2. Add a wire port (vertex) to the middle of the line.
    3. Add a voltage source to the port. (1 V, 0°, 50 Ω).
  4. Create the reflector in the Yagi-Uda antenna.
    1. Create a line.
      • Start point: (-S0*lambda, 0, -L0*lambda)
      • End point: (-S0*lambda, 0, L0*lambda)
      • Label: reflector
  5. Create the first director in the Yagi-Uda antenna.
    1. Create a line.
      • Start point: (S1*lambda, 0, -L2*lambda)
      • End point: (S1*lambda, 0, L2*lambda)
      • Label: director1
  6. Create the second director in the Yagi-Uda antenna.
    1. Create a line.
      • Start point: ((S1+ S2)*lambda, 0, -L3*lambda)
      • End point: ((S1+S2)*lambda, 0, L3*lambda)
      • Label: director2
  7. Set the frequency to freq.

A magnetic plane of symmetry exists about the Y=0 plane. Since the wires are in the Y=0 plane, adding the magnetic symmetry setting would not affect the simulation speed and is therefore ignored.

  1. Define the symmetry about the Z=0 plane as Electric symmetry.
    Tip: Exploit model symmetries (if it exists) in a large or complex model to reduce computational costs.