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.

Define the following variables.
 freq = 1e9 (The operating frequency.)
 fmin = 0.4e9 (The minimum frequency.)
 fmax = 1.5e9 (The maximum frequency.)
 lambda = c0/freq (The frequency for free space wavelength.)
 L0 = 0.2375 (Length of the reflector element in wavelengths.)
 L1 = 0.2265 (Length of the driver element in wavelengths.)
 L2 = 0.223 (Length of the first director element in wavelengths.)
 L3 = 0.223 (Width of the second director element in wavelengths.)
 S0 = 0.3 (Spacing between the reflector and driver element in wavelengths.)
 S1 = 0.3 (Spacing between the driver element and first director element.)
 S2 = 0.3 (Spacing between directors.)
 r = 0.1e3 (Wire radius in mm.)

Create the dipole (driven element) of the YagiUda antenna.

Create a line.
 Start point: (0, 0, L1*lambda)
 End point: (0, 0, L1*lambda)
 Add a wire port (vertex) to the middle of the line.
 Add a voltage source to the port. (1 V, 0°, 50 Ω).

Create a line.

Create the reflector of the YagiUda antenna.

Create a line.
 Start point: (S0*lambda, 0, L0*lambda)
 End point: (S0*lambda, 0, L0*lambda)

Create a line.

Create the first director of the YagiUda antenna.

Create a line.
 Start point: (S1*lambda, 0, L2*lambda)
 End point: (S1*lambda, 0, L2 *lambda)

Create a line.

Create the second director of the YagiUda antenna.

Create a line.
 Start point: ((S1+S2)*lambda, 0, L3*lambda)
 End point: ((S1 + S2)*lambda, 0, L3*lambda)

Create a line.

Set the incident power as follows:
 Select Incident power (transmission line model).
 Source power (Watt): 25
 Real part of Z0: 50
 Set the continuous frequency range from fmin to fmax.

Specify the symmetry about 2 principal planes.
 Y=0: Magnetic symmetry
 Z=0: Electric symmetry
Tip: Exploit model symmetries (if it exists) in a large or complex model to reduce computational costs.