Double passband differential filter having laminated substrate integration waveguide structure

Abstract

The invention discloses a double passband differential filter having a laminated substrate integration waveguide structure. The filter includes a medium substrate, an upper surface metal layer, a middle metal layer and a lower surface metal layer. A metallization through hole array penetrating through the medium substrate is arranged in the medium substrate. Six substrate integration waveguide cavities are defined by the metallization through hole array, the upper surfaced metal layer, the middle metal layer and the lower surface metal layer. The center frequency of the two differential passbands is obtained through adjusting upper layer cavity dimension parameters. At the same time, the middle metal layer is etched with an H-type coupling slot line. Through adjusting the size and the position of the slot line, a demanded coupling index is obtained, so that better frequency response is achieved. According to the invention, a second difference module passband is obtained by utilizing a substrate integration waveguide high order mode, the size of the filter is reduced effectively. Besides, through adjusting the position or the size of the metal etching slot line in the lower surface, common mode rejection and inter-band isolation are improved.

Description

technical field [0001] The invention relates to the technical field of differential filters, in particular to a double-pass band differential filter with laminated substrate integrated waveguide structure. Background technique [0002] The filter is one of the important basic unit circuits of the circuit system. It is widely used in microwave communication, radar navigation, electronic countermeasures, satellite communication, ballistic guidance, test instruments and other systems. It is an indispensable and important device in microwave and millimeter wave systems. The quality of its performance often directly affects the performance index of the entire communication system. In practical engineering applications, the time required from the specification of filter technical indicators to the finished product will be shorter and shorter. It will be an inevitable trend in engineering design and market competition to quickly and accurately design high-performance microwave filt...

AI Technical Summary

Problems solved by technology

[0004] However, at present, the substrate-integrated waveguide technology has not been maturely applied to the design of differential filters. Differential filters still have problems such as large size, difficult processing, low integration, and low common-mode rejection and band-to-band isolation.

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