Abstract: The present invention relates to a coaxial cavity resonator having walls delimiting cavity, and one resonator body having a conductive rod with a first end being in short circuit relation to a first wall of the cavity walls. the first end a cross-sectional area. The resonator further includes a first conductive supportive plate with a first side connected to the first end of each rod. The first side has a larger area than the cross-sectional area of the first end of the rod and a second side, opposite the first side, fo the supportive plate is electrically connected to the first wall. A retainer is provided in the first cavity wall to guide the supportive plate, and an attachment is provided to secure the first supportive plate to the retainer. The invention also relates to a filter and a use of a resonator component in a filter.

Abstract: The construction is a coaxial cavity resonator (20, 30, 40, 50) comprising at least one conductive body (11, 31), which body is open at one end and shortened from a quarter-wave resonator. The conductive body includes a main rod (16), which is in one end attached to the cavity wall (15), and a main disc (17) attached to the free end of the main rod (16). The cavity (12) further comprises one or more conductive plates (21, 41, 51) located between the main disc (17) and the side walls (13), at the first side (17a) of, and out of galvanic contact with, the main disc (17). The shortening is carried out by creating air-insulated extra capacitance between the resonator cavity walls via the conductive plates and a mechanical structure at the open end of the conductive body.

Abstract: The invention relates to an air-insulated coaxial resonator, which is particularly suitable for a structural part in duplex filters. The resonator has an inner conductor (301) extended at one end, so that it forms extra capacitance with the cover (303) of the resonator and the upper part (302y) of the outer conductor. Because of the extra capacitance, a resonator of a certain frequency is shorter than a corresponding quarter-wave resonator. Because of this it is also mechanically stronger and is more stable in its properties. The extension of the inner conductor and the shortening of the construction also have a dissipation-reducing effect. The extension (304, 305, 306a, 306b) can also be used for tuning the resonator and for coupling to the adjacent circuit elements. In a construction according to the invention, a third harmonic of the basic frequency component does not occur, which is a remarkable advantage in the manufacture of filters.

Abstract: The present invention relates to a coaxial cavity resonator comprising walls delimiting a cavity, and one resonator body comprising a conductive rod having a first end being in short circuit relation to a first wall of the cavity walls, the first end having a cross-sectional area. The resonator further comprises a first conductive supportive plate having a first side being connected to the first end of each rod, the first side having a larger area than the cross-sectional area of the first end of the rod and a second side, opposite the first side, of the supportive plate being electrically connected to the first wall. A retainer is provided in the first cavity wall to guide the supportive plate, and an attachment is provided to secure the first supportive plate to the retainer. The invention also relates to a filter and a use of a resonator component in a filter.