Waveguide to coax transition

Hi to all,
I am working in a waveguide to coas transition in ku band. I can improve the transition matching. I have tried with screws and so on.
someone can help me?

use search. this qwestion was disqussed before .

There are numerous and very different transitions available. If you have access to a microwave lab take a look at some of the WR-62 transitions. s11 on the order of 20dB is practical with some care.

You might find just the style that fits your application.