Cavity filter

Abstract

This invention discloses a cavity filter, including a cavity, a complex number of resonant rods, and a coupler. The cavity has a bottom wall. The resonant rods include a first resonant rod, a second resonant rod, and a third resonant rod, which are sequentially adjacent and spaced apart on the bottom wall. The first resonant rod is configured to couple with the third resonant rod. The coupler is a suppression ring disposed on the bottom wall, spaced apart from the resonant rods, and located between the first and third resonant rods. The suppression ring includes a ring portion and has a groove with its opening facing away from the bottom wall. This cavity filter can operate stably in both high and low temperature environments. It uses a simple suppression ring as the coupler instead of a conventional flybar structure to enhance out-of-band suppression and reduce debugging difficulty and sensitivity.

Claims

1. A cavity filter, comprising a cavity, a complex resonant rod, and a coupling element, the cavity having a bottom wall, the resonant rod comprising a first resonant rod, a second resonant rod, and a third resonant rod sequentially adjacent to and spaced apart from each other on the bottom wall, the first resonant rod being configured to couple with the third resonant rod, wherein: The coupling element is a suppression ring disposed on the bottom wall. The suppression ring is spaced apart from the resonant rod and is located between the first resonant rod and the third resonant rod. The suppression ring includes a ring portion and has a groove with an opening facing away from the bottom wall.

2. The cavity filter as described in claim 1, wherein: The distance between the suppression ring and the resonant rod is not less than 0.5 mm.

3. The cavity filter as described in claim 1, wherein: The suppression ring is integrally formed with the cavity.

4. The cavity filter as described in claim 3, wherein: The ring extends vertically from the bottom wall, and the ring and the bottom wall cooperate to form the groove.

5. The cavity filter as described in claim 3, wherein: The outer wall of the ring is an arc surface, or the outer wall of the ring comprises a plurality of planes.

6. The cavity filter as claimed in claim 1, wherein: The suppression ring is fixedly connected to the bottom wall by fasteners.

7. The cavity filter as described in claim 6, wherein: The suppression ring also includes a bottom, which mates with the ring portion to form the groove. The bottom has a through hole through which the fastener passes and is fixed to the bottom wall.

8. The cavity filter as described in claim 7, wherein: The bottom wall is provided with a boss, the bottom abuts against the boss, and the fastener passes through the through hole and is fixed to the boss.

9. The cavity filter as claimed in claim 7, wherein: The suppression ring also includes a flange disposed on the side of the ring portion away from the bottom, the flange extending radially outward from the ring portion.

10. The cavity filter as described in any one of claims 1 to 9, wherein: The resonant rod also includes a fourth resonant rod disposed on the bottom wall. The fourth resonant rod is adjacent to and spaced apart from the first resonant rod and the third resonant rod. The first resonant rod is configured to couple with the fourth resonant rod. The suppression ring includes a first suppression ring and a second suppression ring. The first suppression ring is located between the first resonant rod and the third resonant rod, and the second suppression ring is located between the first resonant rod and the fourth resonant rod.

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