Adjustable mechanical filter

Abstract

The invention discloses an adjustable mechanical filter, which comprises a DC motor, a transmission device and a resonance device, wherein the DC motor is arranged above the transmission device, the resonance device is arranged below the transmission device, and the transmission device and the resonance device are isolated by means of a cover plate; the transmission device comprises a transmissionshaft and a bracket, the transmission shaft is fixedly connected with the DC motor, the transmission shaft and the bracket are movably connected by means of a lead screw structure, vertically downward tuning rods are evenly fixed on the bracket, and the lower ends of the tuning rods extend into resonant cavities; the resonance device comprises a filter cavity body, the cover plate, the resonant cavities and the tuning rods; the filter cavity body is of an enclosed cuboid structure, and four resonant cavities are distributed in the filter cavity body in front-rear symmetry, and the adjacent resonant cavities are connected by means of a coupling groove. The adjustable mechanical filter utilizes differential frequency compensation inside the resonant cavities, and achieves the consistency oftuning rod displacement and resonant frequency variation, thereby realizing the stability of amplitude-frequency features of the filter.

Description

technical field [0001] The invention relates to a mechanical filter, in particular to an adjustable mechanical filter. Background technique [0002] A mechanical filter refers to a filter composed of a mechanical vibrator, a mechanical coupling element, and an electromechanical transducer. It has the performance characteristics of high selectivity, high reliability and high stability, and has the advantages of small size, light weight, low cost and suitable for automatic production, so it has been widely used in the field of electronic equipment. Tunable mechanical filters are mechanical filters with adjustable operating frequency. [0003] Usually, an adjustable mechanical filter adopts a transmission mechanism to synchronously control the resonant frequency of multiple resonant cavities in structure, so as to realize the function of changing the working frequency. However, the traditional tunable mechanical filter has the following disadvantages: (1) When the filter need...

AI Technical Summary

Problems solved by technology

However, the traditional tunable mechanical filter has the following disadvantages: (1) When the filter needs a wide frequency adjustment range, it is difficult to achieve a stable amplitude-frequency response, and the frequency of the resonator varies with the tuning position. The consistency is poor

(2) The filter has large frequency drift and low stability in a wide temperature range, which affects practical applications

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