CIRCULAR WAVEGUIDE RESONATOR TYPE BAND PASS FILTER

摘要

PROBLEM TO BE SOLVED: To decrease both amplitude deviation and group delay time deviation within a pass band by setting the same axial direction between the 1st and 2nd coupling adjustment screws or the 3rd and 4th coupling adjustment screws and also adjusting the size of a 1st capacitive coupling window formed on a 1st bulkhead or a 3rd capacitive coupling window formed on a 2nd bulkhead. SOLUTION: A circular waveguide resonator type band pass filter(BPF) includes four circular waveguide resonators 10a to 10d which are vertically placed in a U-shaped form by putting the resonators 10a and 10b on the resonators 10c and 10d. Then the resonators 10a/10c are capacitively coupled to the resonators 10b/10d through the capacitive coupling windows 33a, 33b/33c and 33d which are formed on a bulkhead 32. Furthermore, the resonators 10b and 10c are capacitively coupled together via a 1st capacitive element consisting of a capacitive coupling plate. The coupling adjustment screws are placed at each prescribed position and in each prescribed direction of resonators 10a to 10d respectively.