集成电路宏模型综述

本文对集成电路宏模型的发展作了综述。集成电路宏模型是分析和设计大型网络的一种有效方法。文中叙述了它的概念、基本假设和建模方法。着重讨论了数字、模拟和数-模混合集成电路宏模型,并指出了尚待解决的问题。     

由模拟向数字地面电视的过滤

本介绍了德国DVB－T覆盖目标的定位,“绿草地规划”、由模拟向数字地面发射的转换,分析讨论了几种可能的转换方案;以一个DVB－T网络规划模型为例,给出了适合不同接收方式的规划参数的选择,对比了它们的费用,对DVB－T的经济性进行了分析。     

多媒体TVS—LAN的选型研究

针对信息高速公路的迅猛发展以及电视台对于多媒体技术和高速网络技术的迫切需求，本文研究了多媒体网络的基本概念和功能，分析了目前的网络发展水平，提出了采用ＡＴＭ技术以及快速以太网技术混合构成ＴＶＳ－ＬＡＮ的基础是一种性能／价格比较好的网络建设方案，能够适应电视台目前和今后多媒体要求。文章另外讨论了几种网络操作系统的优劣。     

HDSL ADSL FTTC HFC有线接入钢技术（下）

介绍了高比特率数字用户环路的系统结构，原理及应用；不对称数字用户环路的技术特点及应用；光纤到路边的网络结构，应用及网络的升级，光纤－同轴混合网的网络结构以及上述接入网技术经济比，并讨论了ＨＦＣ技术与当今通信系统数字化的关系。     

GSM与WCDMA混合组网策略研究

对GSM和WCDMA网络进行混合组网是移动通信网络的必经阶段,混合组网时所执行的组网策略的优劣直接决定着移动通信网络的服务质量和后续发展。文章对两种网络制式的核心网网元结构融合进行了研究,之后对混合网络的组网策略进行了详细分析和讨论。     

HDSL ADSL FTTC HFC 有线接入网技术（上）

介绍了高比特率数字用户环路的系统结构，原理及应用；不对称数字用户环路的技术特点及应用；光纤到路边的网络结构，应用及网络的升级；光纤－同轴混合网的网络结构以及上述接入网技术经济比，并讨论了ＨＦＣ技术与当今通信系统数字化的关系。     

模拟/数字混合信号电路技术发展动态

叙述了国内外模拟和数字混合信号电路发展现状,重点讨论了国内外高性能模拟、射频电路、DSP、A/D转换器和SOC等器件研发和应用的一些情况,指出了这些器件在数模混合信号电路技术发展进程中的作用.     

传输网络测试分析仪CDS883

产品概述 CDS883是康特德威公司一台高性能的数字／模拟电视传输网络测试分析仪。它除了兼容传统的模拟电视测量外，还特别针对数字电视QAM调制中的通道功率、调制误差率和误码率测量设计了专门的电路。适用于数字、模拟混合网络测量及双向网络建设和改造。     

一种新的互连网络拥挤控制

本文详细讨论了互连网络拥挤控制；指出了一般网络内拥挤控制方法不能成功地应用于互连网络的原因，首次提出了一种新的互连网络的拥挤控制方法，它视互连网络为一黑匣，完全利用互连设备－网间连接器的功能进行拥挤控制，计算和模拟分析验证了该方法的突出特性，并与Ｒ．Ｊａｉｎ（１９８６）提出的拥挤控制法进行了比较。     

NPLS原理及其技术优势

本讨论了MPLS的设计思路和工作原理，详细分析了利用MPLS技术构建核心网络对比于其他技术－－IP报路由器技术和ATM核心网络技术－－所具有的优势。     

压电-电磁复合式俘能器设计及能量收集测试

设计了一种压电-电磁复合式俘能器,利用机电耦合状态方程推导了输出功率表达式。应用试验测试对比分析了压电式、电磁式、复合式俘能器的输出特性,结果表明,复合式俘能器的3dB带宽比压电式、电磁式俘能器分别增大了67%、25%,最大功率提高了38%、118%。设计了压电-电磁复合式俘能器能量收集电路,分别利用LTC3588、LTC3108芯片收集压电俘能单元、电磁俘能单元输出的电能,并用超级电容存储。分别应用3种俘能器进行超级电容充电测试,结果表明,复合式俘能器的充电时间比压电式、电磁式俘能器分别减少了29%和52%。     

Compact, Wideband Bandstop Filters With Sharp Rejection Characteristic

A compact unit of parallel coupled transmission line is presented for design of a compact, sharp-rejection, wideband bandstop filter (BSF). The rejection depth and bandwidth can be easily controlled by the coupled-line parameters. A lossless transmission line model is used for filter analysis. Design equations and graphs are presented in order to facilitate the design procedure. Theoretical prediction is verified in microstrip line by fabricating a prototype single section coupled-line BSF.     

Solution methods for transient and dynamic stability

The transient stability study is used to examine the dynamic behavior of a power system following a disturbance. Transient stability programs have grown in the size of the power system under study, in the duration of the study, and in the magnitude of the disturbance. Each prime mover is represented by as few as two or as many as forty ordinary differential equations. These equations are coupled to a set of algebraic equations (two per node) which describe the network. Available programs frequently use explicit fixed step integration methods and the sequential solution of the differential and algebraic equations. Recent advances in solution methods have been directed toward implicit integration techniques and the simultaneous solution of the whole set of differential-algebraic equations. The transient stability problem, the unit models currently in use, and recent advances in solution methods are briefly reviewed. A dynamic stability program is described which incorporates comprehensive dynamic models of prime movers; the results of several experiments using this program are presented.     

Modeling of Eye-Diagram Distortion and Data-Dependent Jitter in Meander Delay Lines on High-Speed Printed Circuit Boards (PCBs) Based on a Time-Domain Even-Mode and Odd-Mode Analysis

Crosstalk induced in a meander delay line produces a significant amount of waveform distortion and data-dependent jitter at the output port. This paper introduces an interpretation of the eye-diagram distortion and the jitter generation mechanism based on a time-domain even- and odd-mode analysis of a coupled transmission line structure. From the proposed analysis, this paper proposes jitter-estimation equations for both the short and long unit line delay cases. The eye-diagram distortion and timing jitter are predicted and estimated, respectively. In order to verify the jitter-estimation equations, a series of microstrip-type printed circuit board test vehicles with the meander delay line are fabricated and tested. The measured jitter shows good agreement with the proposed jitter-estimation equations.      

Coupled Power Equations for Backward Waves

Two waves traveling in opposite directions that are coupled by a random coupling function are considered. These two waves can be described in a standard way by coupled wave equations. It is possible to derive coupled equations for the power carried by these two waves. The form of the coupled power equations differs depending on the assumptions that are made for the initial conditions. The validity of the coupled power equations has been confirmed by a computer-simulated experiment.     

Time-Domain Perturbational Analysis of Nonuniformly Coupled Transmission Lines

A method of analyzing the time-domain behavior of a pair of nonuniformly coupled, dispersionless transmission lines is presented. The coupling coefficient of the system is assumed to be slowly varying with position. The set of coupled equations is transformed into a form for which the method of characteristics applies. Instead of numerically integrating the coupled equations, we decouple the equations by writing the solution in the form of a perturbational series. The resulting zeroth-order term corresponds to the inverse transform of the WKB approximation in the frequency domain, which contains only the wavefront and amplitude information. The higher order terms can be directly interpreted as reflections along the lines. Causality is satisfied to all orders. This method has the advantage of easier implementation, and is more versatile than frequency-domain methods as well as the brute-force numerical integration of the coupled partial differential equations.     

Oblique scattering from lossy strip structures with one-dimensionalperiodicity

The intentional addition of loss to a periodic structure can be used as a technique to alter its scattering characteristics. The problem of an oblique plane wave incident on an array with one-dimensional periodicity is examined. The unit cell of the array is composed of a number of thin resistive strips. The obliqueness of the incident plane wave combined with the lossy nature of the structure causes the transverse electric (TE) to zˆ and the transverse magnetic (TM) to zˆ fields to couple. To analyze the described problem, two coupled electric field integral equations that have as unknowns the equivalent surface currents on the strips in the unit cell are derived. The integral equations are discretized and solved approximately using the method of moments with subdomain basis and testing functions. The periodic Green's function is efficiently calculated using the Poisson summation formula. The interaction of the structure with the surrounding environment is described in terms of a generalized scattering matrix. Results are presented showing the TE/TM coupling behavior as strip resistance is increased for representative structures     

任意镜像阻抗平行耦合线滤波器的设计

任意镜像阻抗平行耦合线滤波器与传统的平行耦合线滤波器相比,通过选择合理的镜像阻抗,可以得到合适的耦合线的宽度与缝隙,因而使滤波器更容易加工。首先从理论上推导了任意镜像阻抗平行耦合线滤波器的设计公式。根据此理论,设计了80Ω的任意镜像阻抗平行耦合线滤波器。通过EM仿真验证了设计公式的正确性与准确性。     

Frequency Entrainment of Coupled Hodgkin-Huxley-Type Oscillators for Modeling Gastro-Intestinal Electrical Activity

The concept of linked oscillators applied to the modeling of electrical rhythms in the mammalian digestive tract is extended to cover the use of Hodgkin-Huxley-type dynamics. as the basic oscillating unit. The singe action potential of the normal Hodgkin-Huxley equations is converted into auto-rhythmic behavior either by the addition of a shunt conductance term or by increasing the power of the non-linear potassium conductance term to 6. Interconnection of units of this type using either resistive, capacitive, orinductive terms causes entrainment at a frequency not greater than the highest uncoupled frequency in the array. Multiple solutions have not been found in contrast to coupled Van der Pol oscillators.     

Analytical and numerical solution to the two-potentialZakharov-Shabat inverse scattering problem

An analytical and a numerical method are presented in order to solve the inverse scattering problem associated with the two-potential Zakharov-Shabat coupled mode equations. The numerical solution, which uses leapfrogging in space and time, represents a direct numerical solution to the coupled Gel'fand-Levitan-Marchenko (GLM) integral equations as an extension of the authors' previous work on GLM equations of simpler form. The analytical method, which is applied for one-pole reflection coefficients, consists in constructing appropriate differential operators which transform the coupled GLM equations to ordinary linear differential equations. An application of these methods for nonuniform transmission line synthesis is presented