hybrid coupler

Hi
Check Pozar's "Microwave Engineering"
or Google.

tyassin thx for reply.
i have something problem, how to calculate airbox for 90 degree Hybrid branch-Line Coupler ?

Hi

Do you simulate in HFSS?
If so, then make a box with a distance of λ/4 to the nearest point of the coupler.

If you have access to a planar simulator, I would advise you to use that. As it is properly easier to draw the coupler and faster at simulating.

Regards