Tunable filter

Abstract

The invention provides a tunable filter comprising a cavity, a cover plate which is assembled on the cavity and a plurality of tuning screw rods; at least two resonators are arranged in the cavity; every tuning screw rod respectively penetrates through each resonator; inductor devices capable of adjusting the coupling quantity between the tuning screw rods and the cover plate and the resonators are arranged; and the inductor devices are wound on the tuning screw rods. An electromagnetic field in an inductor is changed by changing the current which flows through the inductor or the direction of the current, so that a multi-band filtering function can be realized without manual debugging, performance indexes of the filter are guaranteed under different frequency while the filter is tunable, the frequency of the filter is tunable, the product cost is greatly reduced while the same functions are realized, the size is reduced, the material cost is reduced, simultaneously the workload of debugging and assembly is reduced, the miniaturization of the product is realized, and social resources are greatly saved.

Description

technical field [0001] The invention relates to the field of wireless communication, in particular to an improvement of an adjustable filter. Background technique [0002] In the past few decades, with the rapid development of wireless mobile communication technology, filters have played an increasingly important role. Existing filters can generally filter out useless interference signals in communication systems to ensure The signal works fine and gets through with minimal loss. See figure 1 As shown, the existing filter 1' is designed through the principle of distributed parameters, and its performance index is realized through the mechanical structure. It is composed of a resonant cavity 11', a resonator 12', a cover plate 13' and a tuning screw 14'. 1' is equivalent to several resonators in series, and each resonator is composed of a series capacitor and an inductance, wherein the inductance corresponds to the diameter of the resonator 12', and the upper surface of the...

AI Technical Summary

Problems solved by technology

See figure 1 As shown, the existing filter 1' is designed through the principle of distributed parameters, and its performance index is realized through the mechanical structure. It is composed of a resonant cavity 11', a resonator 12', a cover plate 13' and a tuning screw 14'. 1' is equivalent to several resonators in series, and each resonator is composed of a series capacitor and an inductance, wherein the inductance corresponds to the diameter of the resonator 12', and the upper surface of the resonator 12' is equivalent to the inner surface of the cover plate 13' For the two plates of the flat capacitor, the filter 1' is adjusted by changing the spacing between the capacitors through the tuning screw 14', and each fixed tuning screw 14' needs to be individually adjusted. Tuning, using manual frequency tuning is heavy workload and high cost, and may also affect the performance of filter 1′

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