| 摘要 |
PURPOSE:To obtain a miniaturized, inexpensive coaxial branching filter by arranging three band-pass filters which have different resonance frequencies and terminals in the same housing. CONSTITUTION:Resonance rods 12, 15, and 18 which are each short-circuited at one end and open at the other end form semicoaxial resonators together with cylindrical cavity parts 11, 14, and 17, and one three-stage coaxial band-pass filter consists of the semicoaxial resonator consisting of a common coupling conductor 2, the cylindrical cavity part 11, and the resonance rod 12, the semicoaxial resonator consisting of a cut 13 for coupling, the cylindrical cavity part 14, and the resonance rod 15, the semicoaxial resonator consisting of a cut 16 for coupling, the cylindrical cavity part 17, and the resonance rod 18, and a coupling conductor 19. Similarly, three three-stage coaxial band-pass filters are arranged in the housing 1, a center conductor as a common terminal 10 is connected to the common coupling conductor 2; and the common coupling conductor 2 is short-circuited at one end and open at the other end as well as the resonance rods and the coupling conductor 19 is connected to the center conductor of a terminal 20. Consequently, the need for a circuit such as a circulator is eliminated, and the small-sized branching filter which has low loss and no reflection delay is obtained.
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