Circuits and Systems
The Long Island Chapter of the Circuits and Systems Society (CAS-04) consists of members with professional interests in the theory, analysis, design and practical implementation of circuits, and the application of circuit theoretical techniques to systems and signal processing. The coverage of this field includes the spectrum of activities from basic scientific theory to industrial applications.
For upcoming CAS lectures and meetings, please visit the
Fundamentals of Magnetics Design: Inductors & Transformers
Arthur Williams - Telebyte
This presentation introduces some basic definitions necessary to understand the subject matter such as permeability, flux density and magnetic hysteresis. The structure of a toroid and its advantages are illustrated. Analysis of the BH curve and the characteristics of inductors such as DC resistance, dielectric losses, core losses, skin effect, magnetic coupling, and Q are discussed.
The effect of an air gap is presented. Toriodal cores are introduced and the design trade-offs of different winding methods and core selection are discussed. Equivalent circuits of transformers is given for both low and high frequency.
Languages, Platforms, & Paradigms: Choosing for Long-Term Fit
Robert Gezelter - RLGSC
Many, if not most of us, have worked with systems where the language, paradigm, or platform was a poor fit to the task at hand. We have seen scientific tasks written in COBOL; string manipulation written in FORTRAN; incomprehensible spreadsheets; and positively impenetrable scripts. Nobody sets out to choose a wrong or create an unnecessarily complex project. Why does it then happen with such regularity?
Incremental engineering is often deceiving. An approach seems simple and more than adequate at the outset, yet as we delve deeper, the reality is more complex. Individual steps do not in and of themselves appreciably contribute to overall complexity; it is the sum of all such steps over time that is disheartening. This is a cost of evolving systems without forethought, a concept familiar to anatomists and evolutionary biologists.
Often, the problem can be avoided by a developing an understanding of the expected evolutionary trajectory. The key to developing this understanding is familiarity with both the positive and negative costs associated with various implementation choices. We will explore: scaling, foundations, presumptions, maintainability, and other consequences surrounding these choices.
Introduction to Virtualization
Morty Eisen - Marcum Technology
A Virtualization is a proven technology that is rapidly transforming the computing landscape and changing the way systems are deployed. There are many types of virtualization - server, network, storage, and more. In this presentation, we demystify these complex terms, explain what they can do for you, and name specific products that provide these functions.
One key issue is how to share resources both within and across systems. Virtualization is required of data center resources, so that the same resources can be shared across multiple users, and if necessary a single user can scale workloads over multiple resources in multiple locations. IT professionals, engineers and management should start to look at the integration of server, storage and network virtualization as an essential part of private and hybrid cloud computing. While this is a multi-year cultural and technical journey for organizations to create an Infrastructure 2.0 environment that will interface with Cloud services, the strategic importance is hard to over-emphasize.
Power Supply Case Histories
John Dunn - Ambertec PE PC
A set of power supply design case histories is presented in which technical issues and difficulties arose which were beyond the resources of the power supply designers to solve. With each situation, the resolution and outcome are presented. Presented situations include totally intractable power supply oscillations against which no loop compensations were effective, infant mortality of power MOSFETs in a seemingly well protected design environment, thermal runaways leading to total power supply destruction after apparently normal operating time periods of hours to days, pulse-width-modulation (PWM) problems due to a design deficiency in the PWM chip itself, conditional feedback instability across a galvanic isolation barrier and peak power damage prevention for transient absorbing diodes in a MIL-STD-704A environment. Underlying mathematical analysis methods brought to bear in these situations are presented. These include non-software-based device parameter curve fitting and software-based exponential equation derivation.
Topology Review of DC/DC Converters
Louis Diana - Texas Instruments
There are numerous Switching Regulator topologies each with advantages and disadvantages. This presentation discusses the various topologies such as Buck Regulators with PWM Control, Synchronous vs. Non-Synchronous, Multi-Phase designs, operating frequencies, filtering, and Continuous, Critical and Discontinuous conduction. Also Boost Regulators, Buck-Boost Regulators and Sepic Regulators are covered. Topics such as Efficiency, Losses, Inductor design and the advantages of Synchronous Rectification are included.
Introduction to PoE and the IEEE 802.3af & 802.3at Standards
Morty Eisen - Marcum Technology
Power over Ethernet or PoE technology describes a system to safely transfer electrical power, along with data, to remote devices over standard category 5 cable in an Ethernet network. This presentation describes the key components of PoE and discusses existing applications for this technology. Also reviewed are the current IEEE 802.3af-2003 standard and the proposed IEEE 802.3at standard that promises to deliver more power to enable a new breed of PoE devices and applications.
John Dunn - Ambertec
A set of situations is presented in which technical issues and difficulties arose over the course of more than forty years and which each defied the resources of one or more engineers. With each situation, the resolution and outcome are presented.
Presented applications include creating an SPDT switching function with only SPST availability and no transistors, measuring a collector current in the face of multi-hundred collector volts with no high voltage differential amplifiers, how to negate a non-removable shunt capacitance from a signal line, how to determine the RMS value of a pulse train waveform without an RMS voltmeter, how to estimate resistor aging effects, the suppression of a voltage reference device's parasitic oscillation, an unexpected source of measurement error when using a magnetic field pick-up coil, the suppression of far-field magnetic field pick-up by audio transformers, signal coupling capacitor placement versus signal isolation requirements, polystable memory elements, a variety of current pumps, a TO-5 packaging booby trap, and many other topics.
Voltage Feedback vs. Current Feedback Amplifiers
Xavier Ramus - Texas instruments
Practical analytical models for both voltage feedback and current feedback amplifiers are developed and used as a tool to demonstrate usage and limitations. Input architectures and trade-offs are discussed with side-by-side comparisons. Presented applications include ADC drivers and DAC output amplifiers.
Using Recursive Differential Equations
John Dunn - Ambertec
An alternative method of circuit analysis versus the use of SPICE is presented. Invoking only first principles, both linear and non-linear circuits can be analyzed under quiescent and/or time varying conditions. Presented applications include electrostatic discharge (ESD) events, electromagnetic interference (EMI) susceptibility, power supply designs and motor drive.
Direct Location Estimation using Indoor Wireless Comm Systems
Peter Voltz - Polytechnic University
In order to estimate the location of an indoor Mobile Station (MS), estimated times of arrival (TOA) can be obtained at each of several access points, or Base Stations. These TOA estimates can then be used to solve for the location of the MS. Alternatively, it is possible to estimate the location of the MS directly by incorporating the received signals at all Base Stations in a maximum likelihood estimator, for example.
This talk discusses two localization techniques based on a statistical model of the channel multipath environment. A maximum likelihood method for TOA estimation is first discussed and compared to an alternative super-resolution technique for OFDM signals in indoor multipath environments. This technique incorporates the received signals at all Base Stations in a maximum likelihood estimator of position, rather than first estimating TOA’s and then localizing. Analytical details and computer simulations are presented.
Introduction to Active and Passive Analog Filter Design
Arthur Williams - Telebyte
This lecture introduces active and passive filter design while presenting a number of circuits and techniques related to filter design and synthesis. Some of these have been developed by the speaker and remained largely unpublished. Topics include Filter Polynomial types, Conventional LC and Active Filters, Design of D-Element Active Low-Pass Filters, Passive Filter Transformations to Improve Realizability, Active All-Pass Filters, Active Amplitude and Delay Equalizer Structures, Attenuators, Power Splitters and Measurement Techniques.
Designing and Deploying Wireless LAN Systems
Morty Eisen - Extricom
An introduction to a smarter deployment of the 802.11 standard is presented, that eliminates the traditional performance limitations caused by RF cell planning, co-channel interference, edge users, rate adaptation, mixed b/g devices, and frequent AP-to-AP handoffs. While adhering to the 802.11 a/b/g standard and remaining completely client-agnostic, the Extricom patented Interference-Free architecture takes a new approach to infrastructure design and deployment. At the heart is the “channel blanket” topology, which allows each Wi-Fi channel to be used everywhere, on every access point, to create blankets of coverage.
Basics of Simulation Technology (SPICE)
Patrick Noonan - National Instruments
Virtual Instrument technology has widely been used for test, measurement and system level design. National Instruments is pioneering a new use of Virtual Instrumentation – the use of advanced measurement and instrumentation techniques that can be used in conjunction with SPICE based simulation technology to improve the overall design, development and testing of circuit level designs. Several design scenarios are given in the area of analog, digital and mixed signal designs to highlight the capability and feasibility of using Virtual Instrumentation techniques in the design flow. A demonstration of a board level Sigma-Delta design using SPICE and Virtual Instrumentation technology is showcased to highlight these concepts. Both the SPICE based simulation and board level design of the Sigma Delta are demonstrated and discussed.
Implications of HDTV Technology on Circuit and System Design
John Lopinto - Communications Specialties
Television technology has completely changed with the introduction of digital High Definition TV broadcasts. The simple days of analog television, which has served us for over 50 years, are now in their twilight. This presentation outlines the basics of digital HDTV technology and the underlying standards. TV facility system design practices and issues, considering mixed analog and digital facilities, and the implications on TV circuit design are discussed. The transition from analog to digital TV systems are also explored, as well as the growing need for fiber optics for signal distribution. In addition, a brief outline of worldwide HDTV activities is presented.
An Overview of 2D Imaging-based Barcode Scanning Technology
Dr. Bradley S. Carlson - Symbol
The use of 2D image sensor arrays to capture and decode barcodes is rapidly gaining acceptance in the marketplace. 2D barcodes are being adopted in several industries including retail, transportation, manufacturing and healthcare for various applications. In this talk the basics of a digital camera system used for scanning barcodes are described including the image sensor technology, optics, digital electronics and software. The pixel electronics of CMOS and CCD array sensors and their architectures are presented. The basics of the optical system are presented with explanations of resolution and depth of field. The hardware/software architecture of the digital system is presented. Examples of products and the applications in which they are used are described.
Scalable Reasoning: Cutting Ontologies Down to Size
Dr. Aaron Kershenbaum - IBM, Watson
There is an immense amount of information currently available in machine-readable form. Some of it is readily available using keyword-based search; e.g., via Google. But much of this information, for example medical knowledge stored in patient records, may be accessed much more effectively via concepts. For example, prospective candidates for clinical surveys may be most readily identified by their matching complex criteria such as “has a family history of cancer but not obesity”. Each of these concepts (e.g., family history of cancer) can be defined in terms of other concepts and relationships among them. It is then possible to infer the presence of a concept even though it is not explicitly stated.
A formal system which defines concepts in terms of other concepts and relationships among them is called an ontology. If we can reason efficiently over ontologies, we can use them as tools for doing concept-based retrieval. In this talk we describe ontologies and ongoing research which has led to the development of algorithms capable of reasoning over very large ontologies efficiently enough to make concept based retrieval feasible in real situations.
Mixed-Signal Systems-on-Chip: Architectures and Design Tools
Dr. Alex Doboli - Stony Brook University
Mixed-signal systems-on-chip (SoC) technology has rapidly evolved in recent years allowing the including on a chip of programmable analog and digital circuits in addition to CPU cores, memory, and I/Os. Programmable mixed-signal SoCs can be customized in short time and at low cost to implement new functionality and performance requirements. On the other hand, SoC based design has a steep learning curve due to the cross-disciplinary nature and complexity of the process. Design automation tools aide not only in reducing design effort and time, but also in the easier tackling of the cross-disciplinary nature of the design.
Passive Network Synthesis: Camelot in our Grasp
Dr. Richard Saeks - Accurate Automation
If engineering is the “Art of Design,” then the ultimate goal of the design engineer is to automate the design process. Indeed, in the first half of the 20th Century, the circuit designers led the engineering world by automating the design of telephone filters and other passive circuits via passive network synthesis. Although this technology was obsoleted in the second half of the century, by advances in solid-state and computing technology, it set the stage for future developments in circuits and systems design automation. Some of the progress towards this goal, and the potential for fully automating the design of modern circuits and systems, are reviewed.
Characteristics of Underground Secondary Power Distribution
Networks for use as a Communication Medium
Ralph Stolowicki - PowerCom Technologies
An overview of a typical power distribution network is reviewed, followed by a number of actual measurement results taken on an underground secondary power distribution network. Topics covered include network characteristic impedance and network path loss. This lecture is intended for system and design engineers involved in the development of communication systems over long distances using secondary power lines in metropolitan areas.
Matching Network Design Using Non-Foster Impedances
Stephen E. Sussman-Fort - EDO
Non-Foster synthesis bypasses the gain-bandwidth limitations of conventional LC matching and achieves superior broadband performance by employing negative circuit elements, which are realized via negative impedance converters. The fundamental concept is to construct a negative-image model of an antenna, which cancels the antenna's parasitic reactance and transforms its frequency-dependent radiation resistance to a constant value.
Successful implementation of negative-image modeling requires the realization of stable, low-loss negative elements. After a discussion of the basic ideas of non-Foster matching, experimental results are presented for broadband, stable, high-Q, grounded negative capacitance. In an experimental confirmation of non-Foster impedance matching for signal reception, a floating negative capacitor is used to cancel a substantial portion of the reactance of a monopole antenna.
Some Interesting Filter Design Configurations & Transformations
Arthur Williams - Telebyte
This lecture presents a number of circuits and techniques, related to filter design and synthesis, that are not discussed in general literature. Some of these circuits and techniques have been developed by the speaker over the years and remained largely unpublished. Specific topics covered include the design of D-element active LPFs, bi-directional impedance converters for resistive loads, a family of zero-phase-shift LPFs and useful passive filter transformations to improve realizability. Other active networks, such as all-pass filters and amplitude/delay equalizer structures, are also discussed.