Linear phase microwave filter - using pairs of circular resonant cavities electrically coupled and supplied by rectangular waveguide

摘要

The microwave filter comprises a number of pairs of circular resonant cavities with holes for allowing the two cavities of each pair to be electrically coupled together and to allow the individual pairs of cavities to be coupled together. The circular resonant cavities are supplied by a rectangular waveguide operating in the rectangular TE10 mode and coupled to the cylindrical wall of the input cavity such that the cavities operate in the circular TE01 mode. The filter may employ three pairs of resonant cavities (6, 6', 7, 7', 8, 8') with the pairs of cavities arranged in a straight line, or with the centre pair (7, 7') being offset relative to the other two pairs (6, 6', 8, 8').