The present invention relates to a rotary joint for joining two waveguides for guiding electromagnetic waves, comprising a first portion adapted to receive a first waveguide, a second portion adapted to receive a second waveguide, and a third portion adapted for polarization rotation and arranged between the first portion and the second portion. The rotary joint is configured such that two portions selected from the group comprising the first portion, the second portion and the third portion are rotatable between at least two different angular positions around a central axis. Further, the rotary joint being configured to switch between a jointed state, in which the portions contact each other for electrical connection, and a non-jointed state. The present invention also relates to a method of operating such a rotary joint and a computer program and a computer readable non-transitory medium for implementing such a method.