quadrifilar helix antenna feeding?

Hi, everyone. I have a question about the quadrifilar helix antenna feeding design. Actually, it requires 4 different output with 0, 90, 180, 270 degree phase difference. Most of the literatures requires a 180 balun with 2-90 degree quadrature hybrid.

I am wondering whether there are any commercial chip or coupler for this type of applications, or any other good design topology which requires simpler feeding structure?

Thanks in advances.

There are a numbeer of modes possible and useful for different siutuations. Look up reference material by Kilgus and see if you can run down a book by Corzine and Mosko on the subject. Both should be helpful. (....and no I do not have an e-book version)

@winglj

Have you searched this Forum on your topic? Here are earlier materials, maybe you find answers or hints in them:

https://www.edaboard.com/viewtopic.php?t=93529

https://www.edaboard.com/viewtopic.php?t=80136

https://www.edaboard.com/viewtopic.php?t=234980

and an AUTHORITY on quadlifilar helix antennas is Walt Maxwell, see mainly Chapter 22 in his book here: http://www.w2du.com/Reflections2.html
and see Appendix13 here: http://www.w2du.com/appendix.html

unkarc

Very Informative Post