Tunable filter for expanding the tuning range

Abstract

Disclosed is a tunable filter for expanding the tuning range. In one embodiment, a filter comprises: a housing with a plurality of cavities defined by walls; resonators received by the cavities; at least one sliding member mounted on an upper portion of the resonator; a main cover coupled to an upper portion of the housing; ; and at least one tuning element coupled to a lower portion of the sliding member, the tuning element being made of a metallic material, wherein the filter is tuned by a sliding operation, and the resonator comprises a first cylindrical conductive part and a second conductive part coupled to an upper portion of the first cylindrical conductive part, the cross section of the second conductive part being in a circular form with a portion thereof being cut-off so as to allow a vertically overlapping area between the tuning element and the second conductive part to diversify along the sliding of the tuning element. With the disclosed filter, a wider tuning range than in the conventional disk-type resonator can advantageously be ensured through a modified configuration of the resonator.

Description

technical field [0001] The present invention relates to a filter, and more particularly to a tunable filter capable of changing filter characteristics such as the center frequency and bandwidth of the filter according to a slide method. Background technique [0002] A filter is a device that passes only signals in a specific frequency band among input frequency signals, and can be realized in various forms. The bandpass frequency of a radio frequency (RF) filter is determined by the inductance and capacitance components of the filter, and at this time, the work of adjusting the bandpass frequency of the filter is called tuning. [0003] In a communication system such as a mobile communication system, an arbitrary frequency band is allocated to a service provider, and the allocated frequency band is divided into a plurality of channels and used. In the existing case, a communication service provider separately manufactures and uses a filter suitable for each frequency band. ...

AI Technical Summary

Problems solved by technology

[0018] In this way, although the tunable filter using the sliding method has the advantage that it can be tuned only by moving the sliding member left and right without the need for the user to rotate the bolt, there is a problem that the tuning range (range) is small.

Therefore, there is a problem that it is difficult to use a tunable filter according to the sliding method when the resonance frequency and bandwidth are to be tuned more largely

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