节点文献
高背板中互连的研究
【作者】 唐世悦；
【导师】 王砚方；
【作者基本信息】 中国科学技术大学 ， 物理电子学， 2006， 博士
【摘要】 本论文受国家自然科学基金资助，项目名称《数字传输信道物理模型的研究》(项目批准号：10505020)。 背板是电信和数据通信中，在技术方面相对落后的部分，但又是(从开发的角度和设备角度看)相对地昂贵的部分，它已经成为提高传输速率的“瓶颈”。提高传输率是电子工业面临的一大挑战，高速背板的设计已经成为高速电路设计和仿真技术的会聚点之一。 电磁场理论的应用已经在微波领域相当成熟。随着高速互连时钟频率的不断提高，互连中电磁场的有限传播速度和波动现象：趋肤效应、介质损耗、辐射损耗开始显现，此时在低频时适用的电路理论已经显现不足。因此越来越多人研究用电磁场分析方法来解决电路设计问题，高速数字电路设计成为电磁场理论的一个新的应用领域。 由于信号和传播模式不同，不可能将成熟的微波设计方法直接搬到互连设计中来。因此，必须根据电路的实际情况，建立合理的物理模型，再将普遍适用的电磁场分析加以简化，并用电磁场全波分析软件进行数值计算，提取参数，实现一套完整的仿真方案。本论文正是在这种思路下分析了高速背板中互连的串扰、差分对、辐射等问题。 在论文第一章里介绍了研究高速背板中互连的现状及意义，对互连线上信号实际带宽的评估做了详细的讨论和计算。最后分析了在高速互连中应用电磁场理论的可行性以及需要的理论支持。 第二章对影响高速互连的各种物理机制作了详细分析；第三章是在这基础上进一步的讨论，根据各种物理机制对互连的影响做工作区域划分，用这样的方式讨论，能更清晰的理解各种影响数据率的物理机制之间的区别和联系。 第四章主要讨论的是多导体中的串扰问题。主要通过建立的多导体模型，用电磁场计算的方法得到串扰的电容、电感矩阵，对串扰的各种噪声、导体间距以及防护线对串扰的影响作了详细分析。 第五章详细分析了差分对特征阻抗及抗串扰能力。最后对差分微带线和差分带状线作了比较，根据它们不同的电磁场分布，推导出两种结构下差分信号的两个分量之间的速度存在差别，以致于差分微带线结构会引入额外的噪声。 第六章是本文的另一主要创新点之一。共模辐射逐渐成为影响现代高频电路的主要原因，而高速背板的特殊结构，共模辐射的危害更是严重。目前对辐射的预测，往往不是用数值预测，也不是用具体表达式，因为辐射情况复杂，它们的适用范围有限。通常采用的方法是依靠测量经验来对系统进行判断，也就是经验方法。但是背板互连有着它的特殊性，这一章通过对单端互连和差分对互连模型的分析，推导出不同互连结构下共模辐射的具体的数学表达式，对于共模辐射的特性有了更清晰的描述。
【Abstract】 In telecommunication and data communication, backplane is not only the less developed part of the technology, but also the more expensive part considering the cost of equipment development. It has become one bottleneck which blocks the further increase of the data rate. It is a great challenge that the electronics industry faces to improve data rate, and the development of high-speed circuit and the simulation technique have converged to a same point: the design of backplane.The application of electromagnetic field theory is sophisticated in the field of microwave. With the continuous increasing of the interconnection clock frequency, the skin-effect, dielectric loss and radiation loss become obviously in the interconnection. They caused by the limited rate and the fluctuating phenomena of electromagnetic field. The circuit theory that applied in the low frequency interconnection has become weakness. Today, more and more people begin to study how to solve the interconnection design’s problems using the electromagnetic field analysis theory. High-speed digital interconnection has become a new application field of electromagnetic field theory.For the difference of signal property and transmission patterns, the mature design method of microwave can not be used in the field of interconnection directly. The correct method is: giving the practical situation, establishing a logical physical model, simplifying electromagnetic field theory, using the full-wave simulator to extract the parameters, to achieve an integrated simulation scheme. Guided by this principle, the crosstalk, differential pair and radiation of interconnection have been discussed in this paper.In the first chapter, the present status and research significance of high-speed backplane are investigated and how to calculate the bandwidth of a digital signal is introduced. At last, this chapter expounds the theoretical foundation of employing the electric magnetic field theory in the high-speed interconnection.Paper details the physical essence and characteristics of high-speed interconnection in chapter 2 and 3. Furthermore, the bandwidth of signal is divided into distinct performance regions, and these chapters have made a detailed analysis to the characteristics of interconnection inside of each performance region.Chapter 4 is more focused on the crosstalk of multi conductors. Multi conductor capacitance matrix and inductance matrix can be obtained based on electromagnetic calculation, and the crosstalk noise, spacing between adjacent signal lines, guard line are discussed detailedly.The Chapter 5 is about the differential pair. First the characteristic impedance and the ability to resist crosstalk of differential pair are analyzed. At last, electric-field distribution compared to the dielectric distribution is discussed.In the last chapter of this paper, chapter 6, the common-radiation is introduced. Based on the single-end interconnection and differential pair models, the specific mathematic representations of common-radiation are deduced. The results can describe the characteristics of common-radiation clearly and have the certain guiding sense regarding the high-speed backplane appraisal.