slant polarization for horn antenna

hi.
im working on a linear horn array with slant polarization, from 6-18GHz .
could any body help me in a proper horn element with slant polarization.
or a technique to rotate 45 degree the polarization.
thanks.

Try a quarter-wave plate inserted in the feed waveguide diagonal. Use a thin Teflon plate or a similar dielectric.
I doubt it could work over the extremely wide bandwidth, though. Why you simply do not tilt the horns by 45 degrees?

hi.
i think using a wave plate leads to more power loss.
and i want to use it in linear array. tilting the horns make mutual coupling and isolation become difficult.
could i design a dual polarized horn and use it for slant polarization?

I tried quarter-wave plate and saw no loss. BY tilting the horns you can get the goal but you must test the full radiation pattern to check coupling.
Using dual-polarized horns is possible but again you must know the full radiation pattern (not only E and H) to check coupling.
Dual-polarized horn needs to control amplitude and phase to specify the tilt, and all affects the radiation pattern.

I would prefer to experiment, take two horns and see what happens and what works best.

i think using wave plate restricts the bandwidth. designing such wave plates is difficult.
could u help me in design a broad band quarter wave plate? like an HFSS file or a text?
thanks

Sorry, I cannot. I prefer experiments. Your wideband case is quite challenging I think.

thanks for your help .