Transition arrangement comprising a contactless transition or connection between an SIW and a waveguide or an antenna

A transition arrangement for providing at least one transition between a substrate integrated waveguide (SIW) and a waveguide and/or antenna structure or interface, wherein the transition arrangement comprises:

• a first conducting plate or block;
• a second conducting plate or block comprising a plate or split-block assembly comprising at least one waveguide and/or antenna port;
• wherein the SIW is arranged on the first conducting plate or block;
• wherein a number of ridges and/or impedance matching or transforming structures is/are connected to the second conducting plate or block, such that for the transition between the SIW and the waveguide and/or antenna structure or interface, at least one ridge and/or impedance matching or transforming structure is associated with, or extended with, an open circuit λg/4 stub for inverting impedance and providing a short-circuit for electromagnetically coupling an electromagnetic field between the SIW and the ridge or impedance matching or transforming structure in an assembled state of the first and second conducting plates or blocks;
• wherein the impedance matching or transforming structure and the open circuit λg/4 stub are configured such that, when the first and second conducting plates or blocks are assembled, a surface of the open circuit λg/4 stub located opposite to an surface of the stub that is connected to the second plate, will be disposed spaced from a portion of a first ground plane of a the SIW, without any galvanic contact between the SIW and the ridge and/or impedance matching or transforming structure and between the SIW and the open circuit λg/4 stub, such that a contactless, substantially planar, transition is formed between the SIW and the waveguide and/or the antenna structure.