tunable filter

Abstract

The invention relates to a tunable filter, and particularly to a tunable filter which is provided with a frequency tuning mechanism that realizes adjustable central frequency in a mechanical manner, and furthermore a dielectric plate in a waveguide can be moved parallelly with high precision for realizing a required frequency shift. The frequency tuning mechanism (4) of the tunable filter (1) comprises the components of a supporting plate (10) which is configured parallel with the dielectric plate and supports the dielectric plate from outside of the waveguide; a guiding part (20) which prevents rotation of the supporting plate around a single axis and guides the supporting plate for making the supporting plate freely move in a uni-axis direction; a driving part (30) which makes the supporting plate move along the uni-axis direction; and a frame (40) which supports the guiding part and the driving part at fixed positions relative to the waveguide. The driving part comprises the components of a spiral shaft (31) which is supported in the uni-axis direction and is connected with a threaded part at the side of the supporting plate in threaded connection and is driven in a rotatable manner; and a spring (33) which applies a force that makes the supporting plate get away from the frame on the supporting plate.

Description

technical field [0001] The present invention relates to a tunable filter with a frequency tuning mechanism. Background technique [0002] As a bandpass filter using communication frequencies ranging from the microwave frequency band to the millimeter wave frequency band, generally, a waveguide filter is used. Waveguide filters are widely used in communication equipment such as base stations due to their excellent characteristics of low loss and high power durability that can handle high power. [0003] When using a band-pass filter with a fixed pass band, the band-pass filter must be replaced every time the channel of the communication system is changed, which causes an increase in the cost of the communication system. In addition, since the bandwidth depends on the communication system, in order to reduce the cost of the communication system, etc., there is a need for a tunable filter capable of adjusting the center frequency while maintaining the required bandwidth. [0...

AI Technical Summary

Problems solved by technology

However, with this type of mechanism, the rest position of the dielectric plate fluctuates slightly up and down due to the backlash of the screw part, and there is a problem that high-precision frequency shift cannot be performed due to the slight fluctuation of the position.

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