How to feed a reflector antenna

This article is a practical guide on how to feed a reflector antenna with a horn as a feed.

As an example, we will look at a Cassegrain reflector antenna with a multi-flare horn as feed, solved using the method of moments (MoM). All faces are set to PEC.

The model of a Cassegrain reflector with multi-flare horn feed.

Since the model is solved using SEP and the horn is a waveguide structure, a waveguide port will be used to excite the model.

A good approximation of the physical model is to place the waveguide port in the plane where the waveguide transitions into the coaxial adaptor. The waveguide port must cover the full cross-section of the face. Boundary edges forming the port shape must be set to PEC.

To excite the horn:

• Select the bottom face of the horn where the waveguide would transition into the coaxial adaptor.

Select the bottom PEC face of the horn. The rest of the model is hidden.

• Add a waveguide port to the selected face.

A waveguide port is added to the bottom PEC face of the horn.

• Add a waveguide source to the waveguide port.

A waveguide source is added to the waveguide port to excite the model.

See Ports and sources in Feko for more information on ports, sources as well as practical examples on how to feed typical structures in Feko.