High-speed Electronic Systems Research Articles

Eye-Pattern Design for High-Speed Differential Links Using Extended Passive Equalization

The performance of current high-speed consumer electronic systems is often compromised by degradation caused by distortion in eye patterns. This paper proposes a systematic method that uses the voltage transfer function for arbitrary source and load terminations to improve the eye patterns of high-speed differential links with passive components that minimize distortion. This approach is cost-effective since it only utilizes commercially available surface-mount components. The methodology has been validated by measurements in this paper.

25.1: Invited Paper: Discharge Phenomena and Optical Characteristics of Color Plasma Displays Analyzed by High‐Speed Electronic Camera Systems

AbstractAfter the brief explanation about history of color plasma displays including ac and dc type, the fundamental electrode configurations will be described concerning the basic optical and electrical characteristics. In order to clarify the operation mechanisms of color plasma displays with the surface‐ discharge electrode configuration the direct observation of discharge phenomena by using high‐speed electronic camera systems and the operation mechanisms of color plasma displays with the surface‐discharge electrode configuration will be discussed.

A high-performance hybrid electrical-optical interconnection technology for high-speed electronic systems

A new and innovative interconnection technology applicable for printed circuit boards is presented. This technology is widely compatible with the existing design and manufacturing processes and technologies for conventional multilayer pc boards and it combines electrical and optical interconnects on pc board level. It provides the potential for on-board bandwidth of several Gb/s and closes the bottleneck caused by the limited performance of electrical interconnection technology. After giving an overview on the most important basic technologies and first available results and engineering samples, the focus of this paper is on the development of appropriate modeling methodologies and simulation algorithms necessary for designing and optimizing optical on-board interconnects within the conventional electrical pc board environment.

Reducing EMC problems through an electrical/optical interconnection technology

A novel interconnection technology for printed circuit boards (PCBs) is proposed that has the potential to meet the high-performance requirements of future electronic equipment while at the same time, the electromagnetic compatibility (EMC) behavior will be improved significantly. The technology has a far-reaching compatibility with the existing printed circuit-board technology and the existing design and manufacturing processes of the electrical part do not need significant modifications. After a short description of the most important basic technologies for its realization, this paper focuses on a general approach for modeling the resulting hybrid electrical/optical interconnections containing integrated optical highly multimodal waveguides with manufacturing-caused rough surfaces. Especially the transient analysis is addressed in order to provide an efficient analysis methodology and algorithms for timing and signal integrity prediction necessary for designing and manufacturing high-speed electronic systems. The developed overall modeling strategy is explained and first available results are presented.

Crosstalk reduction for VLSI

The performance of high-speed electronic systems is limited by interconnect-related failure modes such as coupled noise. We propose new techniques for alleviating the problems caused by coupling between signal lines on integrated circuits. We show that models used by previous work on coupled noise-constrained layout synthesis do not allow the use of several important degrees of freedom. These degrees of freedom include the ability to utilize dynamic noise margins rather than static noise margins, the dependence of coupled noise on drive strength, and the possibility of using overlaps to reduce susceptibility to noise. We derive an expression for the coupled noise integral and a bound for the peak coupled noise voltage which shows order of magnitude improvements in both accuracy and fidelity compared to the charge sharing model used in previous work. We use the new bounds to guide a greedy channel router, which manipulates exact adjacency information at every stage, allowing it to introduce jogs or doglegs when necessary for coupled noise reduction. Experimental results indicate that our algorithm compares favorably to previous work. The coupled noise is significantly reduced on benchmark instances.

An all-purpose transmission-line model for interconnect simulation in SPICE

A new all-purpose multiconductor transmission-line model is described for efficient and robust interconnect simulation using nonlinear circuit simulators such as SPICE. All types of interconnects, i.e., uniform, nonuniform, lossless, lossy/dispersive, can be handled by the proposed model. Furthermore, coupling of electromagnetic radiation to interconnects can be directly modeled without the need for developing a new subcircuit. Another advantage of the proposed model is that it enables sensitivity analysis with respect to both circuit and interconnect parameters, thus facilitating interconnect circuit optimization. Chebyshev expansions for the spatial variations of the interconnect voltages and currents are used to effect highly accurate numerical approximations of the Telegrapher's equations using as small a number of degrees of freedom as possible. A simple rule of thumb is provided for the selection of the order of the approximation given the frequency bandwidth of interest. Numerical examples are presented to demonstrate the validity of the proposed model and illustrate its application to a variety of interconnect-induced noise interactions in high-speed electronic systems.

Time and frequency domain analysis of integral decoupling capacitors

Decoupling capacitors have been designed and included in high-speed packaging systems to avoid voltage drops across the power supply caused by interconnect inductance. They are also used to reduce simultaneous switching noise between the power supply and device I/O buffers. This paper will review three different measurement methods by which these capacitors were analyzed. It will discuss the possible detriments when making both low frequency and high frequency measurements on electronic packages and surface mount chip components using commercial instruments and fixtures. Two different types of high performance electronic packages with integral decoupling capacitors were analyzed. The models derived from the measurements were included in a circuit simulation to determine the effectiveness of decoupling noise between the device drivers and the system power supply. The results will provide insight into the effectiveness or these types of capacitors used within a high-speed electronic system.

Photoimageable Thick Films for Multichip Modules

The evolution of today's high speed electronic systems has resulted in the need for modules which are able to provide all chip‐to‐chip interconnection with very fine top level and buried conductor traces, and a dielectric with a very dense via grid pattern. As standard thick film technology is capable of pitches only down to 250 µm, new photoimageable thick film pastes have been developed in order to achieve a higher resolution. These materials allow one to combine the advantages of screen printing as a deposition technique with photolithography for the patterning. The image is produced by exposing the printed paste through a photomask to define either lines or vias, so that a very high resolution (50 (µm pitch), similar to that available in MCM‐D or MCM‐L, can be achieved. This paper describes the processing of the photoimageable dielectric and conductor pastes. As an example of the capability of this technology, a module for electro‐optical interconnection is presented.

Multi-log/sub 2/N networks and their applications in high-speed electronic and photonic switching systems

A class of switching networks is proposed to remove the time and space bottlenecks of conventional RAM-controlled switching architectures. The advantages of these networks, such as tolerance of faults O(log/sub 2/N) stages between each inlet-outlet pair, self-routing capability, easy path hunt, and easy fault diagnosis, and their implementation are discussed. Graph theory is used to construct strictly nonblocking or rearrangeable nonblocking networks that are based on the new architecture. >

Flexible Circuit Materials for Use as Interconnections in High Speed Digital Systems

The increasing use of high switching speed systems in both microwave electronics and high speed logic devices has created the need for printed circuit boards which are based on low dielectric constant and low loss materials. In addition, these circuit materials must be capable of withstanding elevated temperatures typical of hostile service environments and of board fabrication processes. Such low dielectric constant rigid boards are commercially available from a few sources. However, there is a growing demand for low dielectric constant flexible printed circuit boards for interconnecting rigid boards or in rigid/flex applications where high speed, fast rise times, controlled impedance and low crosstalk are important. A new family of thin laminates which are suitable for fabrication of flexible low dielectric constant printed circuit boards have been developed by Rogers Corporation. These circuit materials are called ROhyphen;2500 laminates and offer flexible interconnections in high speed electronic systems. RO‐2500 circuit materials are based on microglass reinforced fluorocarbon composites and have a typical dielectric constant of 25. The transmission line properties of these materials have been evaluated by the IPC‐FC‐201 test method. The results indicated that these circuit materials improve the propagation velocity by about 10% and the rise time by about 30% when compared with the same geometry, polyimide film based, flexible PCs in stripline constructions. Also, dimensional stability of these laminates after etch and heat ageing is improved over that of the standard flex circuit materials based on polyimide film. RO‐2500 laminate properties have been evaluated by the IPC‐TM‐650 test methods, which are widely accepted by the flexible PCB industry.

U.S. Employment Service: First 50 Years, 1933–1983

This article reviews some of the landmarks and trends during the first 50 years of the U.S. Employment Service. It was originally written as the introductory chapter of a longer paper, “The Occupational Information Needs and Functions of the Employment Security‐Job Service,” which was submitted at the request of the Occupational Coordinating Council, Washington, D.C., March 1980. The purpose of the chapter was to describe the role and functions of the Employment Service and to show how the service could become more relevant during an age of computerized employment service operations involving highspeed electronic communications and retrieval systems.Under the Reagan administration, much of the federal‐state employment service has been systematically dismantled. The Comprehensive Employment and Training Act (CETA) has been repealed and with it, large parts of the research, development, and counseling capacities have been wiped out. Only the great “supply side” depression of 1980–1983 saved the entire system from being demolished.

Measurement of the absolute acceleration due to gravity using a laser ballistic gravimeter

A unique device is described for highly accurate measurement of the absolute acceleration due to gravity using a ballistic method. Using stabilized lasers, a rubidium frequency standard, and a computercontrolled high-speed electronic counting system, it was possible to achieve a relative error of 4×10–9 with an output of 5000 measurements per twenty four hours. Results are presented of determinations of the absolute acceleration due to gravity at international initial and reference gravimetric points and to investigate tidal and nontidal (secular) variations in gravity.