Patent ID: 7982560

Claim:
A cavity resonator comprising: a printed circuit-board; an upper electrically conductive cap having a three-dimensional structure; and a lower electrically conductive cap having a three-dimensional structure; wherein the structures of the upper cap and the lower cap are identical and the upper and lower caps are mounted on opposite sides of the printed circuit-board; wherein the printed circuit-board includes a layer structure comprising a conductive layer and a dielectric layer; wherein the layer structure of the printed circuit-board includes a re-entrant stub and a first area laterally adjacent to a first portion of a first side of the re-entrant stub and the first area having no conductive layer; wherein the re-entrant stub has at least one notch; and wherein the printed circuit board comprises a first cut-out area that is laterally adjacent to a second portion of the first side of the re-entrant stub.