creating circular polarization in rectangular horn antenna with single feed

Thread Starter

yef smith

Joined Aug 2, 2020
717
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.
 

MrSalts

Joined Apr 2, 2020
2,767
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.
Your research indicates to me, in decreasing order of probability, that want you want to do either...
- can't be done,
- is more difficult than anyone cares to do
- is not needed
- never been thought of (therefore, never attempted)
 

Thread Starter

yef smith

Joined Aug 2, 2020
717
Hello nsaspook,So basickly its a question of how to excite two TM modes in a waveguide with a single feed.
We need propagating modes so TM10 and TM01 could not be used because they do not propogate.
could you please say what modes i need to excite and how could i excite them with a single probe feed?
Thanks.
1647465667576.png
 

nsaspook

Joined Aug 27, 2009
13,086
If you could excite two orthogonal TE10 modes with equal amplitude, and 90◦ out of phase it might work (45◦ slot from the wave-guide top to the horn-feed) but it looks to be very frequency dependent and tricky to build. Never did anything like that so it's a WAG.
 

Ya’akov

Joined Jan 27, 2019
9,078
in the case of a rectangular horn, a septum polarizer can be used. It is placed in the waveguide but requires two probes. I don’t think methods with a single probe could be practical. It seems to me they’d be extremely frequency sensitive.

I am guessing this is not a practical idea, just a thought experiment?
 
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