creating circular polarization in rectangular horn antenna with single feed

[yefj]

Hello ,for circular polarization we need to create two modes with 90 degree phase.
in patch antenna we feed the diagonal to create two modes .
what could be done in rectangular horn antenna to create a circular polarization with a single feed.
i could not find in google anything.
is the some specific method or article i could use?
i could not find anything..

it either use dual feed or use a metamaterial polarizer..
no use of single feed in rectangular horn only.

 

[PlanarMetamaterials]

Creating CP with a single feed can be done, but it's usually done by:

a) Exciting both polarizations with the single source
b) Creating some sort of phase delay in one polarization with respect to the other

For example, a slot or truncated corner in a single-feed patch antenna.

To do this with a horn would be a bit of effort, an equivalent feed might be by inserting the pin at 45-degrees into a square waveguide, and then chamfering two corners of the waveguide to create the phase difference (I haven't seen this done, it's just a guess). I can't say it's been done before.

More simply, you could also use a 3-dB 90-degree coupler to take one input and divide it into two with a phase shift.

 

[mgoulder]

Creating CP with a single feed can be done, but it's usually done by:

a) Exciting both polarizations with the single source
b) Creating some sort of phase delay in one polarization with respect to the other

For example, a slot or truncated corner in a single-feed patch antenna.

To do this with a horn would be a bit of effort, an equivalent feed might be by inserting the pin at 45-degrees into a square waveguide, and then chamfering two corners of the waveguide to create the phase difference (I haven't seen this done, it's just a guess). I can't say it's been done before.

More simply, you could also use a 3-dB 90-degree coupler to take one input and divide it into two with a phase shift.

Rectangular waveguide does not support circular polarization modes.

A septum is typically used to create circular polarization in a circular waveguide. The other option is a polarizer in front of your horn.