Patent ID: 7482897

Claim:
A band stop filter, which comprises: a transmission line with a center conductor and an outer conductor and a plurality of coaxial resonators; the outer conductor forming a unitary conductive housing having an inner space which is divided by conductive partition walls into resonator cavities; each of said resonator cavities containing at least one of the plurality of coaxial resonators, wherein each of the coaxial resonators separately has an electromagnetic coupling to the transmission line; said coupling arranged by a coupling element to form an attenuation peak in a response curve of the filter, the natural frequencies of the coaxial resonators differing from each other to shape the response curve of the filter; wherein the transmission conductor is located inside said housing, running through openings in said partition walls across all the resonator cavities; and wherein the housing is the outer conductor of the transmission line, and a portion of the transmission conductor in a resonator cavity is said coupling element.