Waveguides and transmission lines in gaps between parallel conducting surfaces

A microwave device or part of such device, such as a waveguide, transmission line, waveguide circuit or transmission line circuit, comprising two opposing surfaces of conducting material arranged to form a narrow gap there between, wherein at least one of the surfaces is provided with at least one conducting element, said conducting element being a groove with conducting walls;

• and wherein at least one of the opposing surfaces is provided with means that stops wave propagation in other directions inside the gap than along said groove(s), at least at a frequency of operation, and wherein the two surfaces are connected together for rigidity by a mechanical structure defining an end of the gap at some distance outside a region with guided waves.

A microwave device or part of such device, such as a waveguide, transmission line, waveguide circuit or transmission line circuit, comprising two opposing surfaces of conducting material arranged to form a narrow gap there between, wherein at least one of the surfaces is provided with at least one conducting element, said at least one conducting element being a conducting strip;

• and wherein at least one of the opposing surfaces is provided with means that stops wave propagation in other directions inside the gap than along said conducting strip(s), at least at a frequency of operation, and wherein at least one of the two opposing surfaces comprises small apertures working as antennas or providing a hole for connecting interior gap waveguide circuits to circuits outside the two opposing surfaces.

A microwave device or part of such device, such as a waveguide, transmission line, waveguide circuit or transmission line circuit, comprising two opposing surfaces of conducting material arranged to form a narrow gap there between, and a thin substrate layer being arranged between said two opposing surfaces, and being provided with at least one conducting element, said at least one conducting element being a conducting strip;

• and wherein at least one of the two opposing surfaces is provided with means that stops wave propagation in other directions inside the gap than along said conducting element, at least at a frequency of operation, said thin substrate being arranged on top of said means that stops wave propagation, and the conducting strip being arranged on the opposite side of the thin substrate layer.

A microwave device or part of such device, such as a waveguide, transmission line, waveguide circuit or transmission line circuit, comprising two opposing surfaces of conducting material arranged to form a narrow gap there between, wherein at least one of the surfaces is provided with at least one conducting element, said at least one conducting element being at least one of:

• a conducting ridge, a groove with conducting walls, and a conducting strip;
• and wherein a plurality of metalized via holes are arranged through a layer on top of at least one of said opposing surfaces, the metalized via holes being in metal connection with said surface, whereby said metalized via holes stop wave propagation in other directions inside the gap than along said conducting element(s), at least at the frequency of operation.