# 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 centimetres.
2. Define the following variables:
• freq = 1.645e9 (The operating frequency.)
• lambda = c0/freq * 100 (The wavelength in free space.)
• wa = 12.96 (The width of the waveguide.)
• wb = 6.48 (The height of the waveguide.)
• ha = 55 (The width of the horn.)
• hb = 42.8 (The height of the horn.)
• wl = 30.2 (The length of the waveguide section.)
• fl = wl - lambda/4 (The position of the feed wire in the waveguide.)
• hl = 46 (The length of the horn section.)
• pinlen = lambda / 4.56 (The length of the pin.)
3. Create the waveguide section.
1. Create a cuboid.
• Definition method: Base corner, width, depth, height
• Base corner (C): (-wa/2, -wb/2, -wl)
• Width (W): wa
• Depth (D): wb
• Height (H): wl
4. Delete the face coincident with the UV plane.
5. Create the horn section.
1. Create a flare.
• Definition method: Base centre, width, depth, height, top width, top depth
• Bottom width (Wb): wa
• Bottom depth (Db): wb
• Height (H): hl
• Top width (Wt): ha
• Top depth (Dt): hb
6. Delete the face at the origin and the face opposite to that.
7. Create the feed pin.
1. Create a line.
• Start point: (0, -wb/2, -fl)
• End point: (0, -wb/2 + pinlen, -fl)
8. Add a wire port (segment) to the base of the line.
9. Add a voltage source to the port. (1 V, 0°, 50 Ω).
10. Union all parts.
11. Set the frequency to freq.