Create the model in CADFEKO.
Define any ports and sources required for the model. Specify the operating frequency or
frequency range for the model.
Note: Assume the focal point of the lens is located at the global origin.

Define the following variables.
 freq = 30e9 (The operating frequency.)
 epsr = 6 (relative permittivity.)
 tand = 0.005 (dielectric loss tangent.)
 lambda_0 =
c0/freq (The wavelength in free space.)
 D = lambda_0*10 (lens diameter.)
 F = 1.5*D
(focal length.)

Define the following derived variables for the model construction.
 alpha = arcsin(D/(2*F)) (The included angle to the
edge of the lens.)
 arclength = alpha*
F (The arc length to the edge of the lens.)
 n = sqrt(epsr) (The refraction
index of the lens.)
 T = (2*F  sqrt(4*F^2  D^2))/(2*(n1)) (The
thickness of the length.)
 v0 = (F + T) / (n + 1) (The
ellipse offset distance.)
 u0 = sqrt(n^2  1)
*
v0 (The diameter of the lens.)
 w0 = n*v0 (The major axis
length of the ellipse.)

Define a dielectric medium, glass.
 Relative permittivity:
epsr
 Dielectric Loss tangent:
tand
 Label: Glass
Construct the lens by subtracting a sphere from an elliptical
spheroid.

Create a sphere.
 Definition method: Centre,
radius
 Centre: (0, 0, 0)
 Radius: F

Create the elliptical spheroid.

Create a sphere.
 Definition method: Centre,
radius U, radius V, radius N
 Centre: (0, 0,
v0)
 Radius (Ru): u0
 Radius (Rv): u0
 Radius (Rn): w0

Subtract the sphere from the elliptical spheroid.

Rename Subtract1 to
Lens.
A closed region is by default set to perfect electric conductor (PEC).

Set the region of Lens to Glass.

Set the solver method for the dielectric lens antenna to use RLGO.
Tip: Open the Face properties
dialog and click the Solution tab. From the Solve
with special solution method list, select Ray launching 
geometrical optics (RLGO).
Tip: Use the View by solution tool to verify
the applied solution methods.

Set the frequency to freq.
The dielectric lens is illuminated by a far field pattern source. The
Efield pattern is described by the following equation.
(1)
${E}_{x}={\mathrm{cos}}^{4}(\theta )\text{where}0\le \theta \le \frac{\pi}{2}\text{isthepolaranglefromtheZaxis}\text{.}$

Define the far field data definition.
 Load field data from a Feko Solver (*.ffe) file
 File name:
Ideal_CosineQ4_Xpol.ffe
 Number of theta points:
91
 Number of phi points:
181
 Label: FarFieldData1

Create a far field point source utilising the far field definition,
FarFieldData1.
 Magnitude scale factor:
1
 Phase offset (degrees):
0
 Field data:
FarFieldData1.
Note: The far field source is positioned at the origin which coincide with the
focal point of the lens.