高速PCB板传输线信号完整性分析

发布时间：2018-04-19 15:18

本文选题：高速PCB板 + 传输线　；参考：《华中科技大学》2015年硕士论文

【摘要】：印制电路板(PCB)作为传输高速信号的载体,在通信、计算机、航空等领域扮演着非常重要的角色。随着信息技术的进步,PCB板自身面临着严峻的挑战。一方面,随着PCB板体积的减小和集成度的增加,布线变得密集;另一方面,PCB板上传输的信号上升沿变短、信号速率加大。以上两个方面将导致反射、串扰、辐射等信号完整性问题。信号完整性问题会使数字电路误触发、输出信号波形畸变和系统不稳定等,在很大程度上影响产品的性能。因此,在设计之初需要对传输线进行信号完整性分析,尽可能将出现的问题放在设计阶段解决,从而缩短生成周期并完善PCB板性能,最终提高产品经济效益。首先,本文对高速PCB板上的两种典型布线(即单端线和差分线)进行了信号完整性分析。由于散射参数可以用来评估信号完整性的反射、串扰等问题,故围绕散射参数,从理论上分析两弯曲耦合微带线和差分线间的散射参数。具体来说:对弯曲耦合微带线,采用分段分析方法,将其分为平行部分和弯曲部分。对于平行部分,使用奇偶模分析法;对于弯曲部分,使用?电路建模。对于差分线间的串扰,应用多导体传输线理论中的链路参数矩阵来描述输入和输出端电压和电流的关系,然后将链路参数矩阵转化成混合模散射参数矩阵。最后,结合具体PCB板,应用理论推导和电磁软件仿真,对比结果验证了理论分析的有效性。接着,本文结合16层PCB板,进行一系列信号完整性仿真分析。首先对16层PCB板进行完整性检查,得到串扰超过规定阈值的问题网络。对这些网络进行串扰仿真和电磁干扰(EMI)测量,并将测量结果与国际标准值比较。对于幅值超过标准值的传输线进行优化设计,保证其满足辐射要求。此外,对PCB板上典型传输线进行了散射参数仿真和差分眼图分析。总之,本文依托散射参数,从理论上分析传输线的信号完整性问题。并结合实际PCB板,进行传输线的信号完整性系列仿真。本文提出的PCB板信号完整性仿真分析方法可以为其它PCB板仿真提供借鉴。
[Abstract]:As a carrier of high speed signal, printed circuit board (PCB) plays a very important role in communication, computer, aviation and so on.With the development of information technology, PCB board itself is facing severe challenges.On the one hand, with the decrease of the volume and the increase of integration, the wiring becomes dense; on the other hand, the rising edge of the signal transmitted on the PCB board becomes shorter and the signal rate increases.The above two aspects will lead to signal integrity problems such as reflection, crosstalk and radiation.The signal integrity will cause the digital circuit to trigger by mistake, the output signal waveform distortion and the system instability and so on, which will affect the performance of the product to a great extent.Therefore, it is necessary to analyze the signal integrity of the transmission line at the beginning of design, and to solve the problems as far as possible in the design stage, so as to shorten the generation period and improve the performance of PCB board, and finally improve the economic benefit of the product.Firstly, the signal integrity of two typical cabling lines (single terminal and differential line) on high speed PCB board is analyzed.Because scattering parameters can be used to evaluate the reflection and crosstalk of signal integrity, the scattering parameters between two curved coupled microstrip lines and differential lines are theoretically analyzed around the scattering parameters.To be more specific, the bending coupling microstrip line is divided into parallel part and bending part by subsection analysis method.For parallel parts, use parity mode analysis; for bending parts, use?Circuit modeling.For the crosstalk between differential lines, the link parameter matrix in the theory of multi-conductor transmission lines is used to describe the relationship between input and output voltage and current, and then the link parameter matrix is transformed into a mixed mode scattering parameter matrix.Finally, the effectiveness of the theoretical analysis is verified by theoretical derivation and electromagnetic software simulation combined with the concrete PCB board.Then, a series of signal integrity simulation analysis based on 16-layer PCB board is carried out.Firstly, the integrity of 16-layer PCB board is checked, and the problem network whose crosstalk exceeds the specified threshold is obtained.The crosstalk simulation and EMI measurements of these networks are carried out, and the results are compared with the international standard values.The transmission line whose amplitude exceeds the standard value is optimized to meet the radiation requirement.In addition, the scattering parameters of typical transmission lines on PCB plate are simulated and the differential ophthalmograms are analyzed.In a word, based on scattering parameters, the signal integrity of transmission line is analyzed theoretically.And combined with the actual PCB board, the transmission line signal integrity series simulation.The simulation method of PCB board signal integrity presented in this paper can be used for reference for other PCB board simulation.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN41

【引证文献】