Loaded composite left and right handed quarter-mode substrate-integrated waveguide bandpass filter

Abstract

The invention provides a quarter mode substrate-integrated waveguide band-pass filter loaded with composite left and right hands. The quarter mode substrate-integrated waveguide band-pass filter comprises two segments of microstrip feeders and four quarter mode substrate-integrated waveguide units, wherein the quarter mode substrate-integrated waveguide units are distributed on four quadrants employing the centre of a top metal plane of the band-pass filter as an original point; each waveguide unit comprises a top metal layer, an intermediate dielectric substrate and a bottom metal ground; a row of metal through holes are formed in each intermediate dielectric substrate along the directions of the horizontal axis and the vertical axis; each top metal layer is connected with the corresponding bottom metal ground; and the adjacent quarter mode substrate-integrated waveguide units are coupled through open gaps. By a quarter mode substrate-integrated waveguide technology, the characteristic that the volume of the quarter mode substrate-integrated waveguide band-pass filter is greatly reduced is utilized; the composite left and right hands are introduced to further lower frequency points and to enhance the selectivity; and a miniature broadband band-pass filter with relatively good selectivity and relatively good stop band rejection capability is obtained by combining the characteristics that a quarter mode substrate-integrated waveguide is large in coupling coefficient and low in quality factor.

Description

technical field [0001] The invention belongs to the field of microwave and millimeter filters, in particular to a substrate-integrated waveguide band-pass filter. Background technique [0002] With the development and maturity of modern wireless communication systems, filters as an important part of them have also attracted extensive attention and research. There are various types and functions of filters, but due to the constraints of electromagnetic structures and manufacturing processes, compared with general filters, broadband filters have rarely been reported in recent years, but in modern wireless communication systems, such as various Various radar systems, high-resolution imaging devices, etc. have high requirements for broadband filters. [0003] The filter with traditional metal waveguide structure has the advantages of high power capacity and small insertion loss, but its processing cost is high, the volume is large, and it is not suitable for integration with mo...

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Problems solved by technology

[0003] The traditional metal waveguide structure filter has the advantages of high power capacity and small insertion loss, but its processing cost is high, the volume is large, and it is not suitable for integration with modern planar circuits

The proposed substrate integrated waveguide filter not only inherits the advantages of low loss, high quality factor, and large power capacity of the waveguide, but also introduces the advantages of small size and easy integration with other planar circuits. However, due to its coupling coefficient and Due to the limitation of quality factor, the traditional substrate integrated waveguide still has certain difficulties in making broadband filters, and it is still necessary to face the problem of large size in order to obtain the characteristics of lower frequency bands

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