Cavity filter

Abstract

The invention relates to a cavity filter, which comprises a cavity with one end open, a cover plate installed at the open end of the cavity, a first resonant cavity and a second resonant cavity arranged in the cavity, a partition wall positioned between the first resonant cavity and the second resonant cavity, a cross coupling structure, and a debugging coupling screw installed on the cover plate.A first coupling resonant column is arranged in the first resonant cavity. A second coupling resonant column is arranged in the second resonant cavity. The cross coupling structure comprises a firstcoupling piece formed on the first coupling resonant column and a second coupling piece formed on the second coupling resonant column. The partition wall is provided with a groove. The first couplingpiece and the second coupling piece are oppositely arranged and located on the two sides of the groove respectively, and the tail end of the first coupling piece and the tail end of the second coupling piece are close to the groove. The debugging coupling screw penetrates through the cover plate and extends into the groove. According to the invention, the strength of the transmission zero can be conveniently debugged without dismounting the cover plate, and the adjustable range is large.

Description

【Technical field】 [0001] The invention relates to the field of filters, in particular to a cavity filter. 【Background technique】 [0002] As a key component of the mobile communication system, the cavity filter is widely used in various mobile communication systems. In the development process of today's mobile communication equipment tending to be small, light, thin and high-performance, customers need to pay attention to the passive cavity The out-of-band rejection requirements of the filter are becoming more and more stringent, and the insertion loss requirements are getting smaller and smaller. Therefore, in the passive cavity filter we design, it is usually necessary to add several capacitive cross-coupling rods to generate transmission zeros to meet customer needs. . [0003] Limited to the current machining process, the dimensional accuracy of the filter cannot be effectively improved. At the same time, it is also affected by various aspects such as the assembly diffe...

AI Technical Summary

Problems solved by technology

[0003] Limited to the current machining process, the dimensional accuracy of the filter cannot be effectively improved. At the same time, it is also affected by various aspects such as the assembly difference of the production line production staff and the processing error of the resonance column. During the debugging process of the assembled finished product, the traditional filter The non-adjustable error of the capacitive cross-coupling rod, the transmission zero point generated by the capacitive cross-coupling rod is strong or weak, and some even cannot meet the production index requirements; at the same time, the adjustable range is relatively small, only about 8 megabytes, which is a trend in today's mobile communication equipment During the development of small, light, thin and high performance, the size of the filter is getting smaller and smaller. The adjustable range of the previous adjustable capacitor cross-coupling rod can no longer meet the requirements of the miniaturized filter.

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