Compact micro-band resonant unit low-pass filter with low insertion loss and wide stopband

Abstract

The invention relates to a compact micro-band resonant unit low-pass filter with low insertion loss and a wide stopband, which comprises a dielectric plate (1), a micro-band feed port (2), a micro-band feed line (3), low-resistance open-circuit stub lines (4), a crossed micro-band line (5) and gradually-changed trapezoidal resonant units (6), wherein the micro-band feed port (2), the micro-band feed line (3), the low-resistance open-circuit stub lines (4), the crossed micro-band line (5) and the gradually-changed trapezoidal resonant units (6) are positioned on the dielectric plate (1); the micro-band resonant units are respectively in left-and-right symmetrical structures and up-and-down symmetrical structures; the upper gradually-changed trapezoidal resonant unit (6) and the lower gradually-changed trapezoidal resonant unit (6) are connected by the crossed micro-band line (5) in the middle, wherein the left part of the crossed micro-band line (5) is connected with the micro-band feedline (3) through the low-resistance open-circuit stub lines (4), and the outer end of the micro-band feed line (3) is the micro-band feed port (2); and the characteristics of the upper gradually-changed trapezoidal resonant unit (6) and the lower gradually-changed trapezoidal resonant unit (6) are tuned by the left low-resistance open-circuit stub line (4) and the right low-resistance open-circuit stub line (4), and finally, the connection with the outside is realized through the micro-band feed port (2). The filter has good characteristics of low pass and stopband attenuation, and the designed CMRC metallic patch has small area and has the advantages of small volume, easy integration, and the like.

Description

technical field [0001] The invention relates to a low-pass filter, which can be applied to an intermediate frequency filter of a frequency mixing system. The filter can effectively filter out harmonics and stray signals of local oscillators and radio frequency signals. Background technique [0002] With the development of electronic technology, multi-frequency work is becoming more and more common in radar, microwave, communication and other application systems, and the requirements for separation frequencies are also increased accordingly, requiring the use of a large number of high-performance filters. Therefore, filters are widely used in microwave and millimeter wave circuits. In the application of low frequency band, the lumped parameter filter has good performance, but as the frequency increases above the microwave frequency band, the Q value of the lumped parameter element (capacitor, inductor) drops sharply, causing the insertion loss of the filter to be too high. L...

AI Technical Summary

Problems solved by technology

[0004] Technical problem: In order to overcome the shortcomings of the existing CMRC low-pass filter with high insertion loss and relatively narrow bandwidth of the stop band, the present invention provides a low-insertion loss wide stop-band compact microstrip resonant unit low-pass filter

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