Ultra wide band balance filter based on slotted line structure

Abstract

The invention discloses an ultra wide band balance filter based on a slotted line structure. The ultra wide band balance filter comprises a first filter and a second filter, wherein the first filter and the second filter are the same in structure, symmetrical to each other and connected on a symmetry plane. The first filter comprises a microstrip line structure and the slotted line structure. The slotted line structure comprises 2N+1 slotted line resonators of linear structures, the length of the 2N+1 slotted line resonators is half of the corresponding wave length of the center frequency of the balance filter, and the 2N+1 slotted line resonators are evenly ranked at equal distances on a first straight line and a second straight line, wherein N is a natural number larger than one. The first straight line comprises the N slotted line resonators, the second straight line comprises the N+1 slotted line resonators, centers of the N slotted line resonators on the first straight line are arranged on spaced central axes between the N+1 slotted line resonators on the second straight line respectively, the 2N+1 slotted line resonators are coupled with one another, and the 2N+1 slotted line resonators and the microstrip line structure form N+2 order filters. The balance filter has the advantages of ultra wide bands, high common-mode rejection, the simple structure and the like.

Description

technical field [0001] The invention relates to the field of electronic information, in particular to an ultra-wideband balanced filter based on a slotted line structure. Background technique [0002] In modern wireless communication systems, balanced devices have received more and more attention, because balanced devices can effectively suppress environmental noise and system internal noise. As an essential device in wireless communication systems, balanced filters have been extensively studied in recent years. The balanced filter has a filtering effect under the excitation of the differential mode signal, and can effectively suppress the noise generated in the environment and inside the system, so it is widely used in modern wireless communication circuits. Common-mode signals will reduce its signal-to-noise ratio, so in balanced circuit design, it is necessary to enhance the rejection level of common-mode signals as much as possible. [0003] Existing balanced filter de...

AI Technical Summary

Problems solved by technology

[0003] Existing balanced filter designs are mainly aimed at narrowband systems, because it is difficult to suppress common-mode signals in a wide frequency band, and balanced filters often have very complex structures

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