A junction for connecting two waveguides having substantially a 90-degree angular offset between longitudinal symmetry axes of their cross-sections. The junction has a first interface and a second interface for connecting the waveguides, and at least a first transformer section and a second transformer section, both having cross-sections of substantially rectangular shape, and both having the 90-degree angular offset between longitudinal symmetry axes of their cross-sections. The first and second transformer sections are connected such that a T-shape connection is formed and the first transformer section has a first protruded ridge on its broad wall and the second transformer section has a second protruded ridge on its broad wall. The broad wall with the second ridge is connected to the top narrow wall of the first transformer section and the ridges are located such that they overlap.