Patent ID: 7969260
Filing Date: 2011-06-28
Classification: H01P

Abstract:
1. A variable radio frequency band filter comprising: a housing with a plurality of cavities; a plurality of resonators, wherein one resonator is arranged in each of the cavities; and a tuning arrangement comprising a plurality of tuning structures with one of the tuning structures being arranged in each of the cavities and wherein the tuning structures of the different cavities are mechanically connected such that the tuning structures may be shifted simultaneously in order to simultaneously vary resonance frequencies of the cavities, and wherein each tuning structure includes at least one first metallic surface facing the resonator and at least one second metallic surface facing a wall of the cavity and physically separated from the wall, the first and second metallic surfaces being conductively connected, the second metallic surface being arranged such that a small and essentially uniform gap is formed between the second metallic surface and the wall in order to achieve a virtual grounding of the metallic surfaces.