The invention relates to an arrangement for fastening an inner conductor of a resonator structure and to a method for fastening an inner conductor of a resonator structure to a fastening surface structure. The arrangement comprises a fastening surface structure, which in turn comprises an edge of an opening and the opening defined by the edge, the opening being formed through the fastening surface structure. In addition, the arrangement comprises an inner conductor of a resonator structure arranged at the opening formed through the fastening surface structure, the inner conductor comprising an inner space at least on the portion of the conductor that faces the fastening surface structure, which inner space is defined by the wall of the inner conductor which extends into the opening formed through the fastening surface structure. According to the invention, the fastening arrangement comprises an expander, springy in the radial direction, which is brought and thereby fastened in place into the inner space of the inner conductor placed in the opening in the fastening surface structure, the expander being used for pressing the wall of the inner conductor surrounding the inner space of the inner conductor against the edge of the opening formed through the fastening surface structure, at least on the portion of the opening area where the wall surrounding the inner space of the inner conductor coincides with the edge of the opening formed through the fastening surface structure.
A method and apparatus for making an inner conductor from a conductive body integrally forms a flange on one end of the conductive body. The flange is formed integral to the conductive body by flaring the end of the conductive body. The size and shape of the flange is selected to achieve a desired capacitance surface area for use in a resonator. A resonator housing that has a plurality of cavities can be provided with a plurality of conductive bodies that are inserted into holes located in a bottom wall of the resonator body and that protrude into the plurality of cavities. The resonator housing and conductive bodies are placed onto a flanging fixture to produce a flange on each conductive body of a desired size and shape to achieve a desired capacitance surface area. The plurality of conductive bodies can be simultaneously flanged and fastened to the base of the resonator housing.
