Tunable microwave arrangements

A method for providing a microwave arrangement including a waveguide arrangement and tuning elements for tuning electromagnetic an electromagnetic signal input to the waveguide arrangement, and wherein the waveguide arrangement comprises (i) a layered structure comprising at least two conducting layers and at least one dielectric layer which are arranged in an alternating manner, and (ii) at least one surface mounted waveguide, wherein a second of said conducting layers forming a wall of the surface mounted waveguide which wall incorporates said tuning elements which are arranged to enable control of surface currents generated in said waveguide wall, hence loading the waveguide with a tunable, controllable impedance,

• the method comprising the steps of:
• providing the layered structure comprising the at least two conducting layers and the at least one dielectric layer on a substrate and placing a first of said conducting layers closest to the substrate;
• arranging the second conducting layer so that it forms a wall of the surface mounted waveguide and placing it most distant from the substrate and locating and shaping slots therein to cut or affect surface currents generated in said wall by the input electromagnetic signal, whereby said varactors are provided or connected in said slots;
• pre-patterning the first conducting layer and make it include a cross-shaped recess or an opening in which two stripes are located at a position corresponding to the position on the second, distant, conducting layer receiving the surface mounted waveguide, and so that the cross-shaped recess or opening has dimensions slightly smaller than the dimensions of the portion of the second conducting layer forming the waveguide wall;
• aligning and arranging two stripes at a slight distance from one another, which stripes have respective enlarged outer end portions facing the outer borders of the first conducting layer and adapted to receive a biasing control or tuning voltage, that the second conducting layer consists of a main conductive portion, and stripes arranged in openings or recesses and T-shaped stripes arranged in T-shaped recesses, and being arranged to act as microwave input/output coupling means, wherein the openings or recesses with the stripes are arranged orthogonally to the T-shaped recesses at locations substantially corresponding to the locations of the enlarged outer end portions of the stripes of the first conducting layer, the varactors being formed at overlapping areas between said stripes of the first conducting layer and the second conducting layer at the interfaces of said current cutting slots, interconnecting said first and second conducting layers by vias or similar, and wherein
• the dielectric layer comprises a complex metal oxide at least in areas corresponding to pre-patterned areas forming or comprising the varactors in the second most distant conducting layer.