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Research   Seminars

Spring  2011


  Upcoming Seminar



  
   Dr. Shouri Chatterjee
    
Assistant Professor, Indian Institute of Technology, Delhi
    
    
DateMay 19th, 2:00pm, CESPR 414
Topic:  Energy scavenging from ambient RF - challenges and responses



Abstract

In this talk we will touch upon the three important building blocks of an RF energy harvesting circuit - the antenna, the matching network, and the rectifier. A 377 ohm antenna could be optimal for maximum power transfer between the atmosphere and the antenna. However, a choice for impedance levels in the subsequent circuits would depend on the scavenging circuit architecture. A matching network is used to transfer maximum power from a source (the antenna) to a load (the charging circuit.) Traditional matching networks match an arbitrary load to an arbitrary source at a single frequency. This talk will develop techniques to match an arbitrary source to an arbitrary load at multiple frequencies. A multiband matching network, designed to match the source to the load at properly chosen frequencies, will significantly increase the scavenged power available to the charging circuit. Energy scavenging circuits typically use a variety of charge pumps. In this talk we will discuss Dickson and Cockroft charge pumps as charging circuits. Techniques based on DC-DC boost converters will be introduced. A solution to reduce shoot through power losses, and to reduce constraints on the precision of the clocking in boost converters will be proposed, with preliminary laboratory results.

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Biography

Shouri Chatterjee received the B.Tech. degree in Electrical Engineering from the Indian Institute of Technology, Madras, in 2000, and the M.S. and Ph.D. degrees in Electrical Engineering from Columbia University, New York, in 2002 and 2005, respectively. From 2005 to 2006, he was a design engineer in the wireless division at Silicon Laboratories Inc., Somerset, NJ. Since 2006 he has been with the faculty of the department of Electrical Engineering of the Indian Institute of Technology, Delhi, India. Dr. Chatterjee's research interests are in ultra-low-power and ultra-low-voltage circuits, circuits for on-chip instrumentation, and filter design.


  Previous Seminars



  
   Dr. Mohamad Sawan
    
Professor, Polytechnique Montreal
    
    
DateMay 6th, 3:00pm, Interschool Lab CESPR/Schapiro
Topic:  Brain-Machine Interfaces for Intracortical Biosensing and Treatment of Central Neural System Dysfunctions


Directions

This seminar is part of the distinguished lecture series sponsored by the New York chapter of the IEEE EDS/SSCS, please visit http://edssscs.googlepages.com/


Abstract

Emerging brain-machine interfaces dedicated for biosensing and treatment applications are promising alternative for learning about the intracortical organization, studying the neural activity underlying cognitive functions and pathologies, locating onset seizures, understanding neurons interactions, detecting mind-driven decisions, address complex central neural system dysfunctions by both microelectrostimulation and drug delivery Microsystems. This talk covers circuits and systems techniques used for the design and integration of biosensing and treatment microsystems. Such devices are fully implantable, interconnected to intracortical neural tissues, and include wireless links used to power up such implanted devices and bidirectionally exchange data with external base station. Global view of typical devices altogether with corresponding multidimensional challenges such as power management and high-data rate communication modules will be described. Special attention will be paid to present digital and analog circuit techniques dedicated to parallel detecting and recording of action potentials and seizures through large arrays of electrodes. In addition, microstimulation in the primary visual cortex, which is intended to recover vision for the blind through multisite large arrays of electrodes, will be summarized as case study of the intended treatments.

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Biography

Mohamad Sawan received the Ph.D. degree in 1990 in electrical engineering, from Sherbrooke University, Canada. He joined Polytechnique Montréal in 1991, where he is currently a Professor of Microelectronics and Biomedical Engineering. His scientific interests are the design and test of mixed-signal (analog, digital, RF, MEMS and optic) circuits and Microsystems: design, integration, assembly and validations. These topics are oriented toward the biomedical and telecommunications applications. Dr. Sawan is a holder of a Canada Research Chair in Smart Medical Devices. He is founder director of the Polystim Neurotechnologies Laboratory at Polytechnique Montréal, and he is leading the Microsystems Strategic Alliance of Quebec (ReSMiQ) receiving membership support from 11 Universities.He is founder / co-founder of several International conferences such as NEWCAS, BiOCAS, and ICECS, and he is Editor/ Associate Editor of several International Journals such as the IEEE Transactions on Biomedical Circuits and Systems and the Springer Mixed-signal Letters. Dr. Sawan published more than 450 papers in peer reviewed journals and conference proceedings, offered more than 100 invited talks/keynotes, and he was awarded 6 patents pertaining to the field of biomedical sensors and actuators.Dr. Sawan received several prestigious awards; the most important of them are the Medal of Honor from the President of Lebanon, the Bombardier Award for technology transfer, the Barbara Turnbull Award for medical research in Canada, and the achievement Award from the American University of Science and Technology. Dr. Sawan is Fellow of the IEEE, Fellow of the Canadian Academy of Engineering, Fellow of the Engineering Institute of Canada, and Officer of the Quebec�s National Order.

Refreshments will be served.


  
   Dr. Paul Aiken
 
    Head of Electronics Unit, The University of the West Indies at Mona, Jamaica
   
DateApril 25th, 02:00pm, CEPSR 414
Topic:
Signal and Power Integrity in High Speed Digital Circuits

Abstract

The continuous trend in designing digital circuits and systems for faster speeds has created many new problems for designers. One such problem is the ability to reliably transmit and receive high speed digital data between the various components on a computer mother board. At these high data rates, the signal pathways are transformed into complex transmission lines with many impedance discontinuities that create many levels of signal distortions and attenuation. The increased switching rates of the microprocessor create an increase demand for instantaneous current from the computer power supply, which is usually connected to the mother board through long cables. The power path forms a complex transmission line to these instantaneous current demands, resulting in large voltage droops. This talk will provide an overview of the various signal and power integrity challenges and some techniques that may be used to overcome them. The requirements for performing signal and power integrity analysis along with good design practices and the importance of adequate measurement tools and capabilities will also be highlighted. Finally, some case studies of actual measurements done on Intel motherboards and testers will be showcased.

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Biography

Paul Aiken graduated from FuSEAS, Columbia University in 2004 with a PhD in Electrical Engineering. For the next 2+ years he worked at Intel as a Senior Test Engineer with responsibilities of leading teams to design devices for high volume testing of Microprocessors, RF pathfinding and Signal Integrity. During this time he lead technical teams in developing practical solutions to overcome signal integrity issues that were limiting data rates on motherboards. His contribution assisted in increasing the front side bus (FSB) speed from 800 MBs to 15 GBs. Paul returned to The University of the West Indies in Jamaica to offer his services in developing science and technology across secondary and tertiary schools and within local industries. He currently teaches courses in electronics engineering and physics and performs research in RF circuits design, novel instruments, and electrical characterization of dye sensitized solar cells. Paul also served as an adjunct associate professor of engineering at the University of Technology in Jamaica and was recently elevated to a senior member of the IEEE.


  
   Dr. Shahriar Shahramian
 
    Member of Technical Staff, Alcatel-Lucent Inc.
   
DateApril 22nd, 02:00pm, CEPSR 414
Topic:
Mm-Wave Silicon Circuits for Mixed-Signal Applications

Abstract

The number of reported millimeter-wave and sub-millimeter wave integrated circuits has grown significantly in the recent years. With the ever-increasing performance of Silicon based technologies, many mixed-signal circuits such as data converters and phase-locked loops have found their way into the millimeter-wave realm. In this talk the design methodology, layout techniques and architectural challenges of several millimeter-wave mixed-signal circuits are explored. In particular, the implementation strategy of a 4-bit, 35-GS/s Flash ADC-DAC chain in a SiGe BiCMOS technology is presented. Furthermore, the CMOS realization of a few fundamental ADC building blocks including a 30-GS/s track-and-hold amplifier and an 81-Gb/s retimer is discussed. Finally, the design considerations and performance of the highest frequency phase-locked-loop operating in the W- and D-band is presented.

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Biography

Shahriar Shahramian received his Ph.D. degree from University of Toronto in 2010 where he focused on the design of SiGe and CMOS mm-wave data converters. Shahriar received the Aloha Award in recognition of his B.A.Sc. thesis. He was also the recipient of the Ontario Graduate Scholarship in 2003 and University of Toronto Fellowship from 2004-2006. He was awarded the best paper award at the Compound Semiconductor IC Symposium in 2005. Shahriar also holds six consecutive teaching awards at University of Toronto. He is currently a Member of Technical Staff (MTS) at the Bell Labs division of Alcatel-Lucent, Murray Hill, NJ. His research interests include the design of the next generation wireless and wireline circuits and systems.


  
   Dr. Aleksandar Prodic
 
    Associate Professor, University of Toronto
   
DateApril 15th, 02:00pm, 627 Seeley W. Mudd
Topic:
Flexible Switch-Mode Power Supplies(SMPS) for Low-Power Management

Abstract

The seminar will show new generation of high-frequency flexible mixed-signal controlled switch-mode power supplies (SMPS) for battery powered devices, computers and other applications consuming power from a fraction of watt to several hundreds of watts. Based on the operating conditions or communication with the load, the flexible SMPS dynamically change their mode of operation or even converter topology to achieve numerous advantages over to the existing systems. The flexible SMPS have drastically reduced volume, improved efficiency and offer new features such as fault tolerance, auto-identification, and plug & play operation. The flexible SMPS are designed taking into account stringent requirements for low power consumption of the controller and limited silicon area available for their implementation. The talk will address fundamental design challenges in implementing mixed-signal HF SMPS controllers, present a controller architecture enabling operation at switching frequencies exceeding 100 MHz, and show how various new concepts, such as continuous-time digital signal processing (CT-DSP) and charge balance techniques, can be utilized to achieve previously mentioned advantages.

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Biography

Aleksandar Prodic is an associate professor at the ECE department of the University of Toronto, where in 2004 he formed Laboratory for Power Management and Integrated SMPS. He received his Ph.D. and M.Sc. Degrees from the University of Colorado in Boulder, and Dipl. Ing. degree from the University of Novi Sad, Serbia. His research interests include digital and mixed-signal control of low to medium power high-frequency SMPS, mixed-signal IC design for power electronics, and converter topologies. In this area he has more than 70 journal and conference publications and IPs created by his group are parts of several commercial ICs. Prof Prodic is a recipient of IEEE Power Electronics Transactions Paper Award, and multiple IEEE conference paper prizes. He is especially proud of two Excellence in Teaching Awards, elected and given by the University of Toronto undergraduate students.


  
   Dr. John Khoury
 
    Silicon Labs Inc.
   
Date April 1st, 02:00pm, CEPSR 414
Topic:
Spectrally-Controlled Low-EMI Class-D Audio Amplifiers

Abstract

Class D amplifiers were invented many years ago, but are now receiving new interest due to their high efficiency. These switching amplifiers have one major drawback: they generate significant electromagnetic interference that can impede radio reception. This seminar reviews the operation of Class D amplifiers and will describe new signal processing methods created to control and spectrally shape the EMI. Critical mixed-signal design issues with these types of amplifiers will also be addressed. Experimental results from silicon will be reviewed.

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Biography

John Khoury is a Distinguished Engineer at Silicon Laboratories developing circuits and systems for Class D amplifiers, FM receivers and TV tuners. Previously, he has held various engineering and management positions at Bell Laboratories and Multilink Technology Corp (purchased by Vitesse). In the mid-1990s, John was an Associate Professor of Electrical Engineering at Columbia. He earned the B.S. and Eng.Sc.D. degrees from Columbia and a S.M. degree from MIT.


  
   Dr. Arun Natarajan
 
    IBM T.J. Watson Research Center, NY
   
DateMarch 25th, 02:00pm, 627 Seeley W. Mudd
Topic:
Silicon-based phased arrays for 60GHz applications

Abstract

In this talk, Dr. Natarajan will describe a highly-integrated 60GHz phased-array chipset developed at IBM Research and MediaTek. While the spectrum at 60GHz is attractive for multi-Gb/s wireless applications, the high path-loss is a challenge for robust links, which now have to rely on reflections to create a path between the TX and RX. Phased arrays are an excellent way to establish reflection-based links in the context of dynamic channel conditions. I will discuss the challenges associated with key millimeter-wave phased array building blocks, and with packaging and interfacing the 16-element phased array ICs with antennas. The feature-rich chipset has a RX front-end noise figure of 8dB and per-element TX output power of 13dBm (42dBm EIRP). Reflection-based links at 5.3Gb/s (with path length of 9m) have been demonstrated using the packaged ICs, demonstrating their beam-forming and beam-steering capabilities.

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Biography

Arun Natarajan received the B.Tech. degree in Electrical Engineering from the Indian Institute of Technology, Madras, in 2001 and the M.S. and Ph.D. degrees in Electrical Engineering from the California Institute of Technology (Caltech), Pasadena, in 2003 and 2007, respectively. He joined IBM T. J. Watson Research Center in 2007, where he is currently a Research Staff  Member in the Communication and Computation subsystems area. His research has focused on high-frequency integrated circuits for communication and imaging, and on self-healing circuits for increased yield in sub-micron process technologies. Dr. Natarajan received the Caltech Atwood Fellowship in 2001, the Analog Devices Outstanding Student IC Designer Award in 2004, and the IBM Research Fellowship in 2005.



  Past seminars

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