Contacting Rotary Joint Design

Hi. I need to design a contacting rotary joint from DC to 18 GHz but i don't know how. I tought of a slip ring but when I think about it, a ring would act like a rat race coupler depending on the frequency.So i might get nothing from the recieve port. It will have sma connection and 2 channels. You can see BN 153118 from Spinner. I checked some patents but i found mostly liquid contact ones using mercury.

Contacting joints in that bandwidth exist. Kevlin was one manufacturer. I am not sure if they exist today but you might try searching on them to get a start. Slip rings are certainly not the way to go. Your joint will probably take some form like a coax with sliding contacts on the center and shields. Add some chokes for confusion.

can the joint be a contacting conductor, like liquid mercury?