Crossed coupling substrate integrated waveguide filter with steep side band characteristic

Abstract

The invention discloses a crossed coupling substrate integrated waveguide filter with a steep side band characteristic. Transmission zeros can be formed within a stop band range near to a pass band through introducing additional crossed coupling between non-adjacent cavities, and are very effective to improve the side band transition characteristic and the out-of-band rejection characteristic of the filter, so as to enable the filter to have excellent selectivity, and overcome the defects that the upper side band and the lower side band are asymmetrical, the transition characteristic of the upper side band is moderate and the selectivity is worse in the traditional dominant mode direct coupling SIW rectangular resonant cavity filter. According to the invention, the crossed coupling substrate integrated waveguide filter is simple and feasible, has larger working bandwidth, meanwhile is realized by using a single-layered PCB, and has the advantages that the modeling is simple, in the high band, the insertion loss is little, the transition characteristic of the upper side band and the lower side band is steep, the attenuation characteristic of the stop band is increased, the processing cost is low, the integration is easy and the like.

Description

technical field [0001] The invention relates to an X-band filter, in particular to a cross-coupled substrate-integrated waveguide filter with steep sideband characteristics. The filter uses a substrate-integrated waveguide structure and introduces additional Cross-coupling to form a transmission zero point in the stop band close to the pass band, making the transition characteristics of the upper and lower side bands steeper, especially suitable for applications with higher frequency bands, low loss, high integration, and higher requirements for selectivity. Background technique [0002] The filter is one of the important components in the circuit system and is widely used in communication, radar and other systems. A high-performance filter can reduce the noise figure of the system, reduce the out-of-band interference of the system, improve the sensitivity of the receiving system, etc., thereby greatly improving the performance of the radio frequency system. [0003] In ord...

AI Technical Summary

Problems solved by technology

By introducing additional cross-coupling (Cross-Coupled) between non-adjacent cavities, transmission zeros can be formed in the stop band range close to the pass band, and these transmission zeros can improve the filter's sideband transition characteristics and out-of-band rejection The characteristics are very effective, so that the filter has good selectivity, thereby improving the shortcomings of the traditional main mode direct coupling SIW rectangular resonator filter with asymmetrical upper and lower sidebands, moderate upper sideband transition characteristics, and poor selectivity

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