Common-mode noise suppression circuit adopting complementary structure

Abstract

The invention discloses a common-mode noise suppression circuit adopting a complementary structure. The common-mode noise suppression circuit comprises a dielectric substrate, a differential coupling circuit, a reference grounding layer and a filter circuit, wherein the differential coupling circuit is attached to the upper surface of the dielectric substrate; the reference grounding layer and the filter circuit are attached to the lower surface of the dielectric substrate; the reference grounding layer and the filter circuit are formed by attaching a metal layer to the lower surface of the dielectric substrate and then adopting an etching process on the metal layer; the filter circuit comprises two resonator groups and two Z-shaped short-circuit branch line groups; each resonator group is composed of two complementary quarter-wavelength resonators; and each Z-shaped short-circuit branch line group is composed of two Z-shaped short-circuit branch lines. The common-mode noise suppression circuit has the advantages of being simple in structure, small in size, low in cost, wide in suppression bandwidth, deep in suppression depth and capable of guaranteeing signal integrity of differential signal transmission while achieving common-mode noise suppression.

Description

technical field [0001] The invention relates to a common-mode noise suppression circuit, in particular to a common-mode noise suppression circuit with a complementary structure. Background technique [0002] With the rapid development of digital circuit technology, the signal reliability and integrity of high-speed data transmission has become a hot issue in modern high-speed circuit design. Differential technology has been widely used due to its excellent noise immunity, low crosstalk and low electromagnetic radiation. Today, many high-speed serial link standards implemented by differential technology (such as Sata3.0, PCI4.0, USB3.1, HDMI2.0, etc.) have achieved differential signal transmission exceeding 5Gbps. However, in actual circuit applications, the asymmetry of the differential line will inevitably be caused by the time domain offset and amplitude imbalance generated by the signal source, the process error and wiring discontinuity in the layout design, resulting in...

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Problems solved by technology

The above-mentioned first common-mode noise suppression circuit can only be used in the MHz frequency band, and its size is large, which cannot meet the design requirements of compact high-speed circuits; the above-mentioned second common-mode noise suppression circuit can be used in the GHz frequency band, and its structure is simple. The size is small, which can meet the design requirements of compact high-speed circuits, and has a wide suppression bandwidth, but the production cost of LTCC is high and the process is complicated; the third common-mode noise suppression circuit has a simple structure and low cost, and can meet compact High-speed circuit design requirements, but its suppression bandwidth is narrow, the suppression depth is shallow, and its lateral size is generally too large, which may affect the layout and wiring of the corresponding area on the PCB board

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