A high-frequency assembly includes a cable with at least one dielectric waveguide fiber with a first end and an opposed second end. The high-frequency assembly includes a high-frequency circuit and an interface unit. The at least one dielectric waveguide fiber is at the first end operatively coupled with the high-frequency circuit via the interface unit. The interface unit is designed to inject a high-frequency signal into the dielectric waveguide fiber and/or to receive a high-frequency signal from the at least one dielectric waveguide fiber at the first end. The high-frequency signal has a first signal component of a first polarization direction and a second signal component of a second polarization direction, wherein the high-frequency assembly is designed to inject the first signal component and the second signal component in a defined manner and/or to split a received high-frequency signal into the first signal component and the second signal component.