Compact type self-resonant diaphragm filter

Abstract

The invention discloses a compact type self-resonant diaphragm filter, which comprises an input structure and an output structure, a resonant cavity and a self-resonant diaphragm; the self-resonant diaphragm is provided with at least a coupling hole which is communicated with the resonant cavity, the coupling hole is internally provided with at least a metal boss which is connected with other metal parts only at the bottom of the coupling hole. The upper surface of the resonant cavity and the upper surface of the coupling hole are positioned at a same flat surface, while the lower surfaces thereof are not at the same flat surface. The invention has the advantages of simple structure, small volume, good out-band rejection, wide application range, wide range of work frequency under a certain width of the filter, meanwhile, the invention can also reduce processing difficulty of the filter, is widely applied to an electronic system with varying microwave wave bands, and is especially applied to military and civil fields such as radar, missile guidance, communication and the like.

Description

technical field [0001] The invention relates to a compact filter, in particular to a compact self-resonant diaphragm filter. It can be widely used in electronic systems in various microwave bands, especially in military and civilian fields such as radar, missile guidance, and communication. Background technique [0002] Modern microwave communications, especially satellite communications and mobile communications, require very high filter selectivity. Traditional filters generally obtain better selectivity by increasing the order of the filter, such as Buettwrorth and Chebyshev filters. The weight and volume of the filter obtained in this way are very large, which cannot meet the needs of modern communication. Although the elliptic function filter has good selectivity, it is difficult to realize. Therefore, how to obtain better selectivity without increasing the order of the filter, and at the same time, it is very meaningful to realize it easily. In this way of thinking...

AI Technical Summary

Problems solved by technology

Compared with the direct coupling cavity filter, the length is shortened to one-half. However, due to the strong coupling between the self-resonant diaphragm and the connecting waveguide, it is difficult to realize a narrow-band filter with a relative bandwidth below 10%.

At the same time, in the case of a certain filter width, this filter also has the problem that the center frequency of the passband is difficult to reduce

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