High power FM freq coupler

> Dear Experts,
> can anybody give some reference on FM freq coupler design
with very large power capacity?
> for example, coupling coef is about 40dB,and power handling is more
than 10Kw？
> I guess it should use some ferrite transformer tech. what is
the typical form of heatsink
> for such high freq?Thanks if any response.
>
> best regards,
> Liu Yun
>