adjustable filter

Abstract

A tunable filter includes a first waveguide body (10), a second waveguide body (20), a metal plate (30), a tuning piece (40), and a driving piece (50). A first cavity (11) is disposed in the first waveguide body (10), and a second cavity (21) is disposed in the second waveguide body (20). The metal plate (30) is sandwiched between the first waveguide body (10) and the second waveguide body (20), multiple windows (32) are disposed on the metal plate (30), the multiple windows (32) are distributed along a propagation direction of an electromagnetic wave of the tunable filter, and the first cavity (11) and the second cavity (21) are in communication and are symmetrically distributed on both sides of the metal plate (30). The tuning piece (40) includes a dielectric pull-rod (42) and multiple metal sheets (44) connected to the dielectric pull-rod (42), the dielectric pull-rod (42) protrudes out of the first waveguide body (10) and is connected to the driving piece (50), the multiple metal sheets (44) are disposed inside the first cavity (11), and the multiple metal sheets (44) are disposed corresponding to the multiple windows (32). The driving piece (50) drives the tuning piece (40) to move relative to the metal plate (30), to adjust a frequency of the tunable filter. The tunable filter has good process reliability.

Description

technical field [0001] The present invention relates to the technical field of filters, in particular, to an adjustable filter. Background technique [0002] With the development of wireless communication, the demand for microwave filters is gradually increasing. In order to meet different application environments, different filter structures have emerged. Tunable cavity filters are widely used in communication systems because of their low passband insertion loss, high stopband rejection, easy tuning, and high power tolerance. [0003] The E-plane filter can cancel the frequency modulation and tuning coupling screws through the precision control of the diaphragm, so as to realize the free debugging of the filter, which is beneficial to realize the adjustable structure of the microwave high-frequency filter. The structure of an E-plane filter in the prior art is as follows: a metal plate and a dielectric sheet are arranged in a rectangular waveguide, and the dielectric shee...

AI Technical Summary

Problems solved by technology

However, the dielectric sheet in the structure of this E-plane filter is an integral sheet structure, and the dielectric sheet spans the resonant cavity in the rectangular waveguide of the filter, and the dielectric constant of the dielectric sheet is very low. Such a dielectric sheet has a very small thickness, is difficult to process, and has poor process reliability

Moreover, due to the weak hardness of the dielectric sheet, it is assembled in the E-plane filter, and the anti-vibration ability is also poor. The vibration of the E-plane filter is easy to cause the change of the position of the dielectric sheet, thereby affecting the performance of the E-plane filter. Makes the frequency and performance of the E-plane filter unstable

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