Waveguide to coax transition

Hi to all,
I have to design a circular waveguide to coaxial transition in ku band (10.95GHz-14,5GHz). I am simulating with CST.
Please, can anyone help me?

Thank you so much in advance.
Regards.

Start by defining your requirements and exploring the technical literature.

You might also find it helpful to examine the more common rectangular to coax transitions.