Patent ID: 7489215

Claim:
A coaxial radio frequency filter, comprising: an outer conductor housing with a housing bottom and a housing wall, a neighboring plurality of resonators formed in the outer conductor housing, the resonators respectively comprising an inner conductor, to the housing bottom, which is provided in an associated cavity in the outer conductor housing, the cavities of at least some of neighboring plurality of resonators are connected to one another via at least one coupling opening in the outer conductor housing, and two neighboring resonators being electrically coupled to one another only by means of the coupling openings, and the coupling openings representing apertures, which are respectively bounded laterally by two projections lying opposite in the housing, the electrical coupling between neighboring resonators depending on the size of the apertures, wherein at least one indentation reducing the coupling in the housing bottom is formed between at least some of the inner conductor tubes of neighboring resonators coupled to one another.