A Compact Vertically Coupled Bandpass Waveguide Filter

Abstract

The invention discloses a compact vertically coupled bandpass waveguide filter, comprising: an input port, a vertical coupling part and an output port; the vertical coupling part includes: at the set position of the standard waveguide, vertical A number of coupling sheets are set, and the two ends of the coupling sheets along the width direction of the standard waveguide are respectively provided with notches of a set length; the coupling sheets divide the waveguide into a plurality of resonators in the height direction, and the resonators are connected by coupling The notch on the chip performs vertical coupling; the impedance matching between the waveguide and the resonator is completed through a gradually changing wedge structure between the coupling chip and the input port and the output port respectively. The invention reduces the number of parasitic modes that may be coupled through the coupling plate, greatly reduces the parasitic passband existing near the passband, and improves the out-of-band suppression characteristic at high frequency of the waveguide filter.

Description

technical field [0001] The invention relates to the technical field of filters, in particular to a compact vertical coupling bandpass waveguide filter. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] Traditional waveguide filters tend to be large in size, especially when they are used, they often have a relatively high order (≥3 order). Compared with active devices and planar filters, they are often larger in size, which is not conducive to the miniaturization of the system. At the same time, due to the existence and coupling of many spurious modes, the coupled waveguide filter often has poor high-frequency out-of-band characteristics. [0004] Band-pass filters can suppress signals in other frequency bands while selecting the desired signal, and improve the signal-to-noise ratio of the signal, and are widely used in communication systems...

AI Technical Summary

Problems solved by technology

Air waveguide filters have the advantages of high power capacity, high selectivity, etc., and can cut off low-frequency signals. They are widely used, but they are often large in size. At the same time, due to the existence of many parasitic modes, their out-of-band suppression characteristics at high frequencies are poor.

Although the substrate-integrated waveguide can realize the planarization and miniaturization of the waveguide filter, it needs periodic via holes, which increases the difficulty of processing and sacrifices part of the power capacity.

[0005] Most of the existing waveguide filters use E-plane or H-plane coupling, and the overall structure is large, which is not conducive to the miniaturization of the system. At the same time, due to the existence of parasitic modes, parasitic passbands and out-of-band suppression characteristics are easy to appear at high frequencies. poor

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