CN112787627A

CN112787627A - Discrete jump layer differential signal filter

Info

Publication number: CN112787627A
Application number: CN202011608705.3A
Authority: CN
Inventors: 蔡双娜; 丁敏; 宋志国
Original assignee: Shenzhen Pinchuangxing Technology Co ltd
Current assignee: Shenzhen Pinchuangxing Technology Co ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-05-11

Abstract

The invention discloses a discrete jump layer differential signal filter which comprises a plurality of orderly-arranged resonance units, wherein each resonance unit comprises a crossed dipole formed by metal wires, and the metal wires are arranged into a discrete jump layer structure. When the structural size of the resonance unit is far smaller than the wavelength of electromagnetic waves, the resonance unit can generate negative dielectric constant and show band elimination characteristics in a certain frequency range near the resonance frequency when being excited by an axial electric field, and the resonance unit can be used for inhibiting common mode noise of a differential signal line and ensuring that differential mode components are not influenced.

Description

Discrete jump layer differential signal filter

Technical Field

The present invention relates to filters, and more particularly, to a discrete step differential signal filter.

Background

With the increase of the speed, the complexity of the functions and the increase of the clock frequency of the electronic equipment, the design of the electronic equipment is not as simple as that of the beginning, especially when a large-scale and ultra-large-scale integrated circuit is more and more applied to electronic products, with the increase of the working frequency, when a signal line is transmitted in a package and a printed circuit board, factors such as structural discontinuity, coupling effect and dielectric loss in the circuit board can generate interference on the signal and influence the signal integrity of a circuit system, and in order to improve the influence of stray interference noise on a high-speed signal at high frequency, a differential signal pair can be adopted to replace a traditional single signal line to transmit the signal.

However, in an actual circuit design, the differential signal lines are affected by process errors, circuit wiring, and coupling stray signals, and an asymmetric phenomenon inevitably occurs, and a common mode current signal is generated. This common mode current signal is also referred to as common mode noise. There is a need in the art for improvements in the manner in which common mode noise, when passing through interconnect lines in system packaging structures, can cause significant electromagnetic radiation and interference with itself and surrounding circuitry, which in turn affects the signal integrity and power integrity of the circuitry.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method for preparing a novel food

In order to achieve the purpose, the invention adopts the following specific scheme:

a discrete jump layer differential signal filter comprises a plurality of orderly-arranged resonance units, wherein each resonance unit comprises a crossed dipole formed by metal wires, and the metal wires are arranged into a discrete jump layer structure.

Preferably, the discrete jump layer structure is arranged into an upper layer and a lower layer and is connected through metal holes, so that the metal wires are distributed in a staggered manner up and down between the adjacent metal through holes.

Preferably, the metal lines include metal lines in a horizontal direction and a vertical direction.

Preferably, the projection of the wire is a cross structure.

Preferably, the resonant units are connected with each other in a tight coupling mode.

Preferably, the number of the resonance units is three.

By adopting the technical scheme of the invention, the invention has the following beneficial effects: when the structural size of the resonance unit is far smaller than the wavelength of electromagnetic waves, the resonance unit can generate negative dielectric constant and show band elimination characteristics in a certain frequency range near the resonance frequency when being excited by an axial electric field, and the resonance unit can be used for inhibiting common mode noise of a differential signal line and ensuring that differential mode components are not influenced.

Drawings

FIG. 1 is a top view of a resonating unit of the present invention;

FIG. 2 is a perspective view of a resonating unit of the present invention;

FIG. 3 is a schematic diagram of a filter structure according to the present invention;

fig. 4 is a simulation diagram of the filter of the present invention.

Detailed Description

The invention is further described below with reference to the following figures and specific examples.

Referring to fig. 1 to 2, the present invention provides a discrete jump layer differential signal filter, including a plurality of orderly arranged resonant units, each resonant unit including a crossed dipole formed by

metal wires

1 and 2, wherein the

metal wires

1 and 2 are arranged in a discrete jump layer structure. The discrete jump layer structure is arranged into an upper layer and a lower layer by utilizing a multilayer structure of the PCB and is connected through the metal holes 3, so that the

metal wires

1 and 2 are distributed between the adjacent metal through holes in a staggered manner, the electric size of the unit can be further reduced, the working frequency of the resonance structure is reduced, the length of an induction current path of the unit is increased, the equivalent inductance of the unit is increased, and the minimization of the unit to the maximum degree is realized.

The

metal wires

1 and 2 comprise

metal wires

1 and 2 in the horizontal direction and the vertical direction, and the projection diagrams of the

metal wires

1 and 2 are in a cross structure, so that the circuit propagation path is prolonged. The

metal wires

1 and 2 are arranged on the upper layer surface and the lower layer surface of the PCB substrate and are connected through the metal holes 3, so that the metal wires are integrated. The

metal wires

1 and 2 are distributed between the adjacent metal through holes in a staggered mode, and the purpose is that when the resonant unit is at resonant frequency, the path through which current flows is longer than that of the traditional resonant unit, so that the equivalent inductance of the resonant unit is larger, and good resonant stability can be guaranteed in different polarization modes.

As shown in fig. 3, the resonant unit is etched on a plane between the differential signal lines 4 to form a resonant filter, and when the return current of the differential signal lines 4 passes through the filter, the current distribution path is changed by the disturbance. At this time, the current around the filter is equivalent to an inductance, and the electric field in the resonant unit is equivalent to a capacitance by coupling, so as to form a parallel LC resonant circuit, and generate a stop band characteristic in a certain frequency range to suppress the propagation of noise. The differential signal line 4 is excited by a common mode, the amplitude and the direction of current transmitted on the signal line 4 are the same, and electric field energy is superposed to excite the filter axially. The return current path of the common mode signal is disturbed by the filter and produces a stop band characteristic to suppress the propagation of noise. Therefore, the structure can suppress common mode noise while ensuring that differential mode components are not affected.

The invention adopts a three-order circuit structure, the number of the resonance units is three, the resonance units are connected in a tight coupling mode, and the noise suppression depth can reach 30dB due to the influence of the stop band characteristic of the filter.

As shown in fig. 4, may be used to isolate the propagation of electromagnetic noise in the transmission line and suppress harmonic signals in the package structure. The noise suppression degree can be increased by about 10dB every time the first-order filter is added, and the stop band frequency range can be widened by about 10%, so that the stop band frequency bandwidth range and the noise suppression degree can be increased.

The invention has been described in detail in connection with only a limited number of embodiments and can be applied to high speed signal transmission, such as products like mobile phones, CPEs, MIFI network cards, etc. It is to be understood that the invention is not limited to the disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A discrete jump layer differential signal filter is characterized by comprising a plurality of orderly-arranged resonant units, wherein each resonant unit comprises a crossed dipole formed by metal wires, and the metal wires are arranged into a discrete jump layer structure.

2. The discrete-hop differential signal filter of claim 1, wherein the discrete-hop structure is arranged in two layers, one above the other, and connected by metal vias, such that metal lines are distributed staggered up and down between adjacent metal vias.

3. The discrete-hop differential signal filter of claim 2, wherein the metal lines comprise metal lines in a horizontal direction and a vertical direction.

4. The discrete-hop differential signal filter of claim 3, wherein the projected pattern of metal lines is a cross-shaped structure.

5. The discrete-hop differential signal filter of claim 1, wherein the resonant cells are connected by close coupling.

6. The discrete-hop differential signal filter of claim 5, wherein the number of resonant cells is three.