Ceramic filter with double-blind-groove capacitive coupling structure

Abstract

The invention discloses a ceramic filter with a double-blind-groove capacitive coupling structure. The ceramic filter comprises a filter body, tuning holes, a coupling groove, and the capacitive coupling structure composed of an upper blind groove and a lower blind groove, wherein the outer surface of the filter body is provided with a conductive metal coating; the tuning holes are formed in the upper surface of the body; the tuning holes are blind holes; the coupling groove is a rectangular through groove; and the capacitive coupling structure is composed of the upper blind groove and the lower blind groove which are the same in length, width and height, and is located between the two tuning holes. According to the invention, the capacitive coupling structure composed of the upper blind groove and the lower blind groove are arranged between the two tuning holes, and a coupling amount can be changed by adjusting the length and the height of the blind grooves, so capacitive coupling ofthe ceramic filter is realized; the height of one single blind groove is smaller than half of the height of the filter, so blind slot height limitation does not exist; the lengths of the blind groovesare flexible and adjustable, so the debugging difficulty of capacitive coupling of the ceramic filter is effectively reduced, and the debugging precision of capacitive coupling is improved; and the ceramic filter has the characteristics of simple structure, convenience in design, easiness in production and preparation and the like.

Description

technical field [0001] The invention belongs to the technical field of communication, and more specifically relates to a ceramic filter with a double-blind slot capacitive coupling structure. Background technique [0002] With the development of the fifth-generation mobile communication technology, the frequency used for communication is gradually increasing, and the number of filters required increases, which puts forward higher requirements for the size and performance of the filter. Ceramic filters have broad application prospects in the radio frequency field of base stations due to their excellent properties such as low insertion loss and small size. In order to improve the out-of-band rejection, the ceramic filter usually needs to introduce a capacitive coupling structure to form a cross-coupling, and generate a transmission zero near the working frequency band. [0003] In the prior art, the capacitive coupling between the resonators is usually realized by forming dee...

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Problems solved by technology

[0004] Aiming at the defects of the prior art, the object of the present invention is to provide a ceramic filter with a double-blind slot capacitive coupling structure, which aims to solve the difficulty in debugging the capacitive coupling of the existing ceramic filter, the adjustment accuracy is poor, and it is not easy to produce preparation problem

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