Cavity medium filter and out-band rejection method

Abstract

The invention discloses a cavity medium filter, comprising a cavity. The cavity is provided with a plurality of resonant cavities, each of which is provided with a resonator, wherein some part of the resonant cavities form cross coupling, at least one pair of the resonant cavities are provided with coupling windows, and one of the resonant cavities is taken as a zero cavity and generates reflection with the other resonant cavity to generate transmission zero at one side of a frequency band; and two resonant cavities for cross coupling are provided with cross coupling devices for generating the transmission zero at the other side of the frequency band. Combining with a out-band rejection method of the cavity medium filter, zero cavities and the cross coupling devices are arranged, so that the zero cavities can define that the transmission zero is set at the left side of the frequency band or the right side of the frequency band by adjusting a corresponding tuning pan thereof, and the cross coupling devices can set the transmission zero at the left side of the frequency band or the right side of the frequency band by different arranging modes of the arc parts. By setting the transmission zero at the left side or the right side for the frequency band, the invention can heighten the out-band rejection capability of the whole filter.

Description

【Technical field】 [0001] The invention relates to the field of mobile communication equipment, in particular to a cavity dielectric filter and an out-of-band suppression method thereof. 【technical background】 [0002] In modern mobile communication technology, microwave radio frequency devices have become an indispensable and important part. As a basic radio frequency device, the filter has a series of indicators such as insertion loss, out-of-band rejection, passive intermodulation and power capacity, which have an important impact on the performance of the whole machine. Due to its own loss, the traditional metal coaxial cavity filter cannot obtain a high quality factor (Q value) when the cavity size is limited, resulting in certain restrictions on indicators such as out-of-band rejection and insertion loss. , and the metal surface silver plating treatment and other links will also have a certain impact on the passive intermodulation index. [0003] Most of the existing ...

AI Technical Summary

Problems solved by technology

Due to its own loss, the traditional metal coaxial cavity filter cannot obtain a high quality factor (Q value) when the cavity size is limited, resulting in certain restrictions on indicators such as out-of-band rejection and insertion loss. , and the metal surface silver plating treatment and other links will also have a certain impact on the passive intermodulation index

[0003] Most of the existing cavity dielectric filters suppress the out-of-band signal through the natural fading of the coaxial dielectric resonator itself, and this kind of higher out-of-band suppression can be achieved by increasing the number of coaxial dielectric resonators. It leads to an increase in volume and cost, and is not conducive to the performance optimization of the device

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