Associate Professor Pietro Andreani and Adjunct Professor Sven Mattisson

Publicerad: 2010-12-20

will give tutorials at the 2011 IEEE International Solid-State Circuits Conference (http://isscc.org/), February 20-24 in San Fransisco. ISSCC is the flagship conference of the IEEE Solid-State Circuits Society and is the premier forum for presenting advances in solid-state circuits and systems-on-a-chip. Tutorial by Pietro Andreani: Integrated LC Oscillators Tutorial by Sven Mattisson: Distortion in Cellular Receivers

Integrated LC Oscillators
This tutorial will go through the fundamentals of LC oscillator and LC VCO design, such as basic phase-noise theory, design for low power, low phase noise and, large tuning range (including varactor choice). It will also include other key issues such as supply pushing, LDO-VCO co-design, routing/buffering the oscillator signals in large SoCs, and PLL-VCO co-design for fully integratable frequency synthesis. The goal it to give a thorough overview that will be easy to follow yet comprehensive and in touch with the latest significant research results (e.g. DCOs with extremely fine tuning steps for use in DPLLs) of one of the truly key blocks in today's and tomorrow's radios.

Pietro Andreani received the M.S.E.E. degree from the University of Pisa, Italy, in 1988, and the Ph.D. degree from the Dept. of Electrical and Information Technology (EIT), Lund University, Sweden, in 1999. Between 2001 and 2007, he was Chair Professor at the Center for Physical Electronics, Technical University of Denmark. Since 2007, he has been Associate Professor at EIT, Lund University, working in analog/mixed-mode/RF IC design. He is also a part-time IC designer at ST-Ericsson in Lund. He is a TPC member of both ISSCC and ESSCIRC. He has published several papers on oscillator phase noise and VCOs.

Distortion in Cellular Receivers
In this tutorial we discuss how noise and distortion limits the dynamic range of cellular receivers. The connection between the narrow-band cubic nonlinearity and the properties of typical radio receivers, both for narrow- and wide-band signals, is explained. First the properties of the cubic nonlinearity and its relation to several important narrow-band distortion types are explained. The concept of intercept points and their use to characterize weak MOS and BJT device nonlinearities as well as amplifiers entering compression, with and without feedback, is highlighted. Some linearization techniques are introduced, and the impact of third-order intermodulation for general receivers and second-order intermodulation for low- and zero-IF receivers is explained with circuit examples. Finally, the effects of more wide-band signals are coupled to the narrow-band approximations.

Sven Mattisson received his PhD in Applied Micro Electronics from Lund University in 1986. From 1987 through 1994 he was an Associate Professor in Applied Micro Electronics in Lund where his research was focused on circuit simulation and analog ASIC design. 1995 he joined Ericsson in Lund to work on cellular hand-set development. Presently he is with Ericsson in Lund, where he holds a position as senior expert in analog system design. Since 1996 he is also an Adjunct Professor at Lund University. Dr. Mattisson is one of the principal developers of the Bluetooth concept.

Licentiate seminar by M.Sc. Erik Hertz

Publicerad: 2010-12-20

Abstract-Many consumer products, such as within the computer areas, computer graphics, digital signal processing, communication systems, robotics, navigation, astrophysics, fluid physics, etc. are searching for high computational performance as a consequence of increasingly more advanced algorithms in these applications. Until recently the down scaling of the hardware technology has been able to fulfill these higher demands from the more advanced algorithms with higher clock rates on the chips. This that the development of hardware technology performance has stagnated has moved the interest more over to implementation of algorithms in hardware. Especially within wireless communication the desire for higher transmission rates has increased the interest for algorithm implementation methodologies.

The scope of this thesis is mainly on the developed methodology of parabolic synthesis. The parabolic synthesis methodology is a methodology for implementing approximations of unary functions in hardware. The methodology is described with the criteria's that have to be fulfilled to perform an approximation on a unary function. The hardware architecture of the methodology is described and to this a special hardware that performs the squaring operation.

The outcome of the presented research is a novel methodology for implementing approximations of unary functions such as trigonometric functions, logarithmic functions, as well as square root and division functions etc. The architecture of the processing part automatically gives a high degree of parallelism. The methodology is founded on operations that are simple to implement in hardware such as addition, shifts, multiplication, contributes to that the implementation in hardware is simple to perform. The hardware architecture is characterized by a high degree of parallelism that gives a short critical path and fast computation. The structure of the methodology will also assure an area efficient hardware implementation.

Date: January 28, 2011 at 10.15
Place: Lecture hall E:2311, E-building, Ole Römers väg 3, Faculty of Engineering, Lund University
Opponent (Särskild granskare): Oscar Gustafsson, PhD, Docent, Department of Electrical Engineering, Linköping University
Title: Parabolic Synthesis
Series of licentiate and doctoral theses, Department of Electrical and Information Technology, Vol. 27, ISBN 978-91-7473-069-2, ISSN 1654-790X Nr 28, 2011.
Supervisor: Professor Peter Nilsson
Examiner: Professor Henrik Sjöland

Disputation Ulrike Richter

Publicerad: 2010-11-17

Datum: 2010-12-10, kl 10:15
Plats: Lecture hall E:1406, E-building, Ole Römers väg 3, Lund University Faculty of Engineering
Opponent: Professor Ki Chon. Worcester Polytechnic Institute, Worecester, USA
U. Richter:
Spatial characterization and estimation of intracardiac propagation patterns during atrial fibrillation?
Series of licentiate and doctoral theses, Department of Electrical and Information Technology, Vol. 27, ISSN 1654-790X, 2010.
Abstract: This doctoral thesis is in the field of biomedical signal processing with focus on methods for the analysis of atrial fibrillation (AF). Paper I of the present thesis addresses the challenge of extracting spatial properties of AF from body surface signals. Different parameters are extracted to estimate the preferred direction of atrial activation and the complexity of the atrial activation pattern. In addition, the relation of the spatial properties to AF organization, which is quantified by AF frequency, is evaluated. While no significant correlation between the preferred direction of atrial activation and AF frequency could be observed, the complexity of the atrial activation pattern was found to increase with AF frequency. The remaining three papers deal with the analysis of the propagation of the electrical activity in the atria during AF based on intracardiac signals. In Paper II, a time-domain method to quantify propagation patterns along a linear catheter based on the detected atrial activation times is developed. Taking aspects on intra-atrial signal organization into account, the detected activation times are combined into wavefronts, and parameters related to the consistency of the wavefronts over time and the activation order along the catheter are extracted. Furthermore, the potential relationship of the extracted parameters to established measures from body surface signals is investigated. While the degree of wavefront consistency was not reflected by the applied body surface measures, AF frequency could distinguish between recordings with different degrees of intra-atrial signal organization. This supports the role of AF frequency as an organization measure of AF. In Paper III, a novel method to analyze intracardiac propagation patterns based on causality analysis in the frequency domain is introduced. In particular, the approach is based on the partial directed coherence (PDC), which evaluates directional coupling between multiple signals in the frequency domain. The potential of the method is illustrated with simulation scenarios based on a detailed ionic model of the human atrial cell as well as with real data recordings, selected to present typical propagation mechanisms and recording situations in atrial tachyarrhythmias. For simulated data, the PDC is correctly reflecting the direction of coupling and thus the propagation between all recording sites. For real data, clear propagation patterns are identified which agree with previous clinical observations. Thus, the results illustrate the ability of the novel approach to identify propagation patterns from intracardiac signals during AF which can provide important information about the underlying AF mechanisms, potentially improving the planning and outcome of ablation. However, spurious couplings over long distances can be observed when analyzing real data comprised by a large number of simultaneously recorded signals, which gives room for further improvement of the method. The derivation of the PDC is entirely based on the fit of a multivariate autoregressive (MVAR) model, commonly estimated by the least-squares (LS) method. In Paper IV, the adaptive group least absolute selection and shrinkage operator (LASSO) is introduced in order to avoid overfitting of the MVAR model and to incorporate prior information such as sparsity of the solution. The sparsity can be motivated by the observation that direct couplings over longer distances are likely to be zero during AF; an information which has been further incorporated by proposing distance-adaptive group LASSO. In simulations, adaptive and distance-adaptive group LASSO are found to be superior to LS estimation in terms of both detection and estimation accuracy. In addition, the results of both simulations and real data analysis indicate that further improvements can be achieved when the distance between the recording sites is known or can be estimated. This further promotes the PDC as a method for analysis of AF propagation patterns, which may contribute to a better understanding of AF mechanisms as well as improved AF treatment.

Disputation Frida Sandberg

Publicerad: 2010-11-05

Datum: 2010-11-26, kl 10:15
Plats: Lectur hall E:1406, Building E, Ole Römers väg 3, Lund University Faculty of Engineering
Opponent: Professor Olivier Meste. University of Nice, France
F. Sandberg:
Novel Approaches to ECG-Based Modeling and Characterization
ISSN 1654-709X, No 26, 2010.
Abstract: This thesis deals with signal processing algorithms for analysis of the electrocardiogram (ECG) during atrial fibrillation (AF). Such analysis can be used for diagnosing patients, and for monitoring and predicting their response to various treatment. The thesis comprises an introduction and five papers describing methods for ECG-based modeling and characterization of AF. Paper I--IV deal with methods for characterization of the atrial activity, whereas Paper V deals with modeling of the ventricular response, both problems with the assumption that AF is present. In Paper I, a number of measures characterizing the atrial activity in the ECG, obtained using time-frequency analysis as well as nonlinear methods, are evaluated for their ability to predict spontaneous termination of AF. The AF frequency, i.e, the repetition rate of the atrial fibrillatory waves of the ECG, proved to be a significant factor for discrimination between terminating and non-terminating AF. Noise is a common problem in ECG signals, particularly in long-term ambulatory recordings. Hence, robust algorithms for analysis and characterization are required. In Paper II, a robust method for tracking the AF frequency in noisy signals is presented. The method is based on a hidden Markov model (HMM), which takes the harmonic pattern of the atrial activity into account. Using the HMM-based method, the average RMS error of the frequency estimates at high noise levels was significantly lower compared to existing methods. In Paper III, the HMM-based method is employed for analysis of 24-h ambulatory ECG signals in order to explore circadian variation in AF frequency. Circadian variations reflect autonomic modulation; attenuation or absence of such variations may help to diagnose patients. Methods based on curve fitting, autocorrelation, and joint variation, respectively, are employed to quantify circadian variations, showing that it is present in most patients with long-standing persistent AF, although the short-term variation is considerable. In Paper IV, 24-h ambulatory ECG recordings with paroxysmal and persistent AF are analyzed using an entropy-based method for characterization of the atrial activity. Short segments are classified based on these measures, showing that it is feasible to distinguish between patient with paroxysmal and persistent AF from 10-s ECGs; the average classification rate was above 95%. The ventricular response during AF is mainly determined by the AV nodal blocking of atrial impulses. In Paper V, a new model-based approach for analysis of the ventricular response during AF is proposed. The model integrates physiological properties of the AV node and the atrial fibrillatory rate; the model parameters can be estimated from ECG signals. Results show that ventricular response is sufficiently represented by the estimated model in a majority of the recordings; in 85.7% of the analyzed 30-min segments the model fit was considered accurate, and that changes of AV nodal properties caused by autonomic modulation could be tracked through the estimated model parameters. In summary, the work within this thesis contributes with new methods for non-invasive analysis of AF, which can be used to tailor and evaluate different strategies for AF treatment.

10e årliga elevkonferensen

Publicerad: 2010-10-19

Ämnen:
3G/UMTS/HSPA RFID 802.11 WLAN Sensornätverk AdHoc Networking WiMAX Delay Tolerant Networks xDSL GSM/GPRS Cloud Computing LTE IP-telefoni

Keynote speaker: Dr. Magnus C. Ohlsson, Quality Assurance Specialist, System Verification Sweden AB

Detta är den muntliga presentationen av fördjupningsarbeten i kursen ETS130 Komunikationssystem, obligatorisk signaturkurs för C1. Gymnasieklasser från Polhemskolan, Lund, Borgarskolan, Malmö och John Bauer-gymnasiet, Hässleholm, kommer att delta som åhörare.

InfoCom 2010
10e årliga elevkonferensen om Informations- och kommunikationssystem
Lund 29e oktober 2010 9-16
LTH, E-huset (E:A och E:B)

IEEE Distinguished Lecture by Prof. Anthony Ephremides, University of Maryland, USA

Publicerad: 2010-09-13

Den 29 september, kl. 13.15, ger Professor Anthony Ephremides en "IEEE distinguished lecture" i E:2311, E-huset, LTH.

Title: Stable throughput, rate control, and delay in multi-access channels

Abstract: The quest for bridging Information-theoretic and Networking views of shared channels, like the Multi-Access Channel, has utilized many different approaches. In this talk we propose a simple framework to model a 2-user Multi-Access channel that incorporates features of Networking, like random arrivals, queueing, and stability, as well as properties of the physical layer like bit rates and multi-packet reception capability. We characterize the stable throughput region in terms of achievable rate values and explain the connections to the broader issues of rate control. We also consider a related problem of emptying a network in minimum time in terms of rate control.

Biography: Anthony Ephremides holds the Cynthia Kim Professorship of Information Technology at the Electrical and Computer Engineering Department of the University of Maryland in College Park where he holds a joint appointment at the Institute for Systems Research, of which he was among the founding members in 1986. He obtained his PhD in Electrical Engineering from Princeton University in 1971 and has been with the University of Maryland ever since. He has held various visiting positions at other Institutions (including MIT, UC Berkeley, ETH Zurich, INRIA, etc) and co-founded and co-directed a NASA-funded Center on Satellite and Hybrid Communication Networks in 1991. He has been the President of Pontos, Inc, since 1980 and has served as President of the IEEE Information Theory Society in 1987 and as a member of the IEEE Board of Directors in 1989 and 1990. He has been the General Chair and/or the Technical Program Chair of several technical conferences (including the IEEE Information Theory Symposium in1991 and 2000, the IEEE Conference on Decision and Control in 1986, the ACM Mobihoc in 2003, and the IEEE Infocom in 1999). He has served on the Editorial Board of numerous journals and was the Founding Director of the Fairchild Scholars and Doctoral Fellows Program, a University-Industry Partnership from 1981 to 1985. He has received the IEEE Donald E. Fink Prize Paper Award in 1991 and the first ACM Achievement Award for Contributions to Wireless Networking in 1996, as well as the 2000 Fred W. Ellersick MILCOM Best Paper Award, the IEEE Third Millennium Medal, the 2000 Outstanding Systems Engineering Faculty Award from the Institute for Systems Research, and the Kirwan Faculty Research and Scholarship Prize from the University of Maryland in 2001, and a few other official recognitions of his work. He also received the 2006 Aaron Wyner Award for Exceptional Service and Leadership to the IEEE Information Theory Society.

Computer Architecture Guest lectures from ARM

Publicerad: 2010-09-13

Friday Sept 24, 13-15 in E:B. "Lessons from working on the ARM architecture" Covers an overview of the history of the ARM architecture and the key products that have been developed from it. It will include some interesting, and perhaps surprising lessons that can be drawn from it about processor architecture. Richard Grisenthwaite: ARM Fellow and Lead Architect responsible for the evolution of the ARM architecture. "Domain-specific computing: architecture and implementation" This talk will explore some of the ways this has happened in ARM (DSP, Java, audio, video, and graphics), how time has affected those decisions, and what might happen to the need for such domain-specific processors as technologies change. Jem Davies: ARM Fellow and VP of technology, Media Processing Division at ARM.

Lund Circuit Design Workshop

Publicerad: 2010-06-23

The Lund Circuit Design Workshop, September 22-23, will be held at Grand Hotel and Faculty of Engineering, Lund University. The workshop is hosted by the VINNOVA Industrial Excellence Center SoS and by the SSF Strategic Research projects Wireless Communication for Ultra Portable Devices and Wireless with Wires.

Mer information

Disputation Alireza Kazemzadeh

Publicerad: 2010-05-04

Datum: 2010-05-27, kl 10:15
Plats: Lecture Hall E:1406, Department of Electrical and Information Technology, Lund University Faculty of Engineering
Opponent: Dr. Kenneth Lee Ford. University of Sheffield, Dept. of Electronic and Electrical Engineering, Sheffield, UK
A. Kazemzadeh:
Design and Analysis of Nonmagnetic Specular Radar Absorbing Materials
ISBN 978-91-628-8105-4, Department of Electrical and Information Technology, Lund University, 2010.
Abstract: The design and analysis of specular radar absorbing materials are investigated throughout the dissertation. Although the topic has been investigated for more than 60 years by many researchers and numerous designs have been proposed, still many technical challenges are remained unanswered. The basic questions are, e.g., the optimal thickness of a design, the possibility of utilization of unconventional materials in an absorber to meet more design requirements, e.g. thermal or mechanical, than solely the electrical properties, the maximum possible bandwidth achievable with a low profile nonmagnetic coating and the feasibility of designing wideband multilayered absorbers for large scan angles. The thesis proposes systematic solutions for these challenging problems. The dissertation is composed of six peer-reviewed papers. A new versatile design method is proposed in the first paper with outstanding capabilities and remarkable applications. The method is named ''capacitive circuit absorber'' (CCA) and is demonstrated with different design examples to verify its superiority in comparison to the other design approaches. For example, the possibility of utilizing high permittivity dielectric spacers in conjunction with frequency selective surfaces (FSS) in wideband designs is illustrated. The second paper deals with ultra thin absorbers. Recently different proposals based on meta-materials or electromagnetic band-gap structures were suggested for low profile absorbers. The thesis shows that the absorption mechanisms in ultra thin structures are due to excitation of longitude electric field component and no meta-material effect is involved in the absorption process. It is demonstrated that TM cavity modes of patch antennas can approximate fairly accurately the absorption frequency in both periodic and finite extent absorbers. The design of multilayered Jaumann and FSS based absorbers for large scan angles are presented in the third paper. The possibility of extension of the scan and frequency compensation techniques, formerly formulated for single resistive layer designs, to multilayered absorbers is illustrated. It is shown that in contrast to single resistive layer designs, there are some degrees of freedom in the selection of the dielectric layers. Design of ultra wideband absorbers, bandwidth ratios in order of 10:1, with optimal thickness is studied in the fourth paper. It is shown that for achieving an ultra wideband design with optimal thickness, utilization of different spatial periodicities for the periodic layers is essential. By the aid of the physical bound for absorbers it is verified that our design approach leads to optimal total thicknesses. Design of thin wideband absorbers is the topic of the fifth paper, where the challenging problem of reasonable tradeoff between bandwidth and thickness is addressed. The effect of mutual coupling between periodic layers and the ground plane on the frequency response of a thin design is investigated and practical methods for minimizing the couplings are introduced. A thin design is proposed for the X-band which has a total thickness very close to the theoretical limit. Finally in the last paper the physical bound on the absorbers, originally published for normal angle of incidence, is extended to arbitrary angle of incidence for different polarizations. Applicability of the new bounds is examined with different design examples.

Seminarium med hedersdoktor Henrik Almeida:
Bredband på koppar – industriforskning och dess samverkan med akademien

Publicerad: 2010-05-24

Henrik Almeida inleder med att presentera sig och därefter kommer han att ge sin personliga syn på:

• Teknikområdet bredband på koppar (DSL)
• Industriforskning
• Hållbar och produktiv samverkan med akademin.

Henrik Almeida är en av årets hedersdoktorer. Den 28 maj promoveras han till hedersdoktor vid LTH tillsammans med arkitekten Sir Peter Cook.

Henrik Almeida är bredbandsexpert och chef för Ericssons enhet för forskning inom bredband på koppar (DSL). Han har en exceptionell förmåga att leda och inspirera forskning och är dessutom en pionjär i att utveckla samverkansformer mellan akademi och industri.

Plats: E:1406 (E-huset LTH)
Tid: Torsdag 27 maj kl. 13.15

I direkt anslutning till seminariet bjuder institutionen på förfriskningar och tårta i sal E:1426

• Kl. 13.00, samling med förfriskningar.
• Kl. 14.15, avslutning med kaffe och tårta.

Mer information

Disputation Markus Törmänen

Publicerad: 2010-04-21

Datum: 2010-05-18, kl 10:15
Plats: Room E:1406, E-building, John Ericssons väg 4, Lund University Faculty of Engineering
Opponent: Professor Kari Halonen. Helsinki University of Technology, Helsinki, Finland
M. Törmänen:
Microwave CMOS VCOs and Front-Ends - using integrated passives on-chip and on-carrier
Vol. 25, ISSN 1654-790X, Department of Electrical and Information Technology, Faculty of Engineering, LTH, Lund University, 2010.
Abstract: The increasing demand for high data rates in wireless communication systems is increasing the requirements on the transceiver front-ends, as they are pushed to utilize more and wider bands at higher frequencies. The work in this thesis is focused on receiver front-ends composed of Low Noise Amplifiers (LNAs), Mixers, and Voltage Controlled Oscillators (VCOs) operating at microwave frequencies. Traditionally, microwave electronics has used exclusive and more expensive semiconductor technologies (III-V materials). However, the rapid development of consumer electronics (e.g. video game consoles) the last decade has pushed the silicon CMOS IC technology towards even smaller feature sizes. This has resulted in high speed transistors (high fT and fmax) with low noise figures. However, as the breakdown voltages have decreased, a lower supply voltage must be used, which has had a negative impact on linearity and dynamic range. Nonetheless, todays downscaled CMOS technology is a feasible alternative for many microwave and even millimeter wave applications. The low quality factor (Q) of passive components on-chip usually limits the high frequency performance. For inductors realized in a standard CMOS process the substrate coupling results in a degraded Q. The quality factor can, however, be improved by moving the passive components off-chip and integrating them on a low loss carrier. This thesis therefore features microwave front-end and VCO designs in CMOS, where some designs have been flip-chip mounted on carriers featuring high Q inductors and low loss baluns. The thesis starts with an introduction to wireless communication, receiver architectures, front-end receiver blocks, and low loss carrier technology, followed by the included papers. The six included papers show the capability of CMOS and carrier technology at microwave frequencies: Papers II, III, and VI demonstrate fully integrated CMOS circuit designs. An LC-VCO using an accumulation mode varactor is presented in Paper II, a QVCO using 4-bit switched tuning is shown in Paper III, and a quadrature receiver front-end (including QVCO) is demonstrated in paper VI. Papers I and IV demonstrate receiver front-ends using low loss baluns on carrier for the LO and RF signals. Paper IV also includes a front-end using single-ended RF input which is converted to differential form in a novel merged LNA and balun. A VCO demonstrating the benefits of a high Q inductor on carrier is presented in Paper V.

Licentiatseminarium Anders Bernland

Publicerad: 2010-04-14

Onsdagen den 5 maj, 2010, kl. 13.15 i E:3139, kommer Anders Bernland att presentera sin licentiatavhandling "Sum Rules and Constraints on Passive Systems – a General Approach and Applications to Electromagnetic Scattering". Univ. Lektor Lars Jonsson från KTH är granskare.

Seminarium: Professor Emeritus Göran Einarsson

Publicerad: 2010-04-22

Måndagen den 3 maj 2010, kl 15.15, i E:A, E-huset, LTH, kommer Professor Emeritus Göran Einarsson att hålla ett seminarium med titeln Mina Universitet.
Efter föredraget serveras enklare förfriskningar i foajén utanför E:1406

Advanced RF Implementation flow course

Publicerad: 2010-03-25

The Department of Electrical and Information Technology (EIT) at Lund University will host a week-long course on *Advanced RF Implementation flow*, organised by IDESA (see below).

The course takes place April 26th-30th, and consists of a number of lectures and computer labs. For more information or registration go to http://www.idesa.rl.ac.uk/ and select the Advanced RF Implementation Flow course.

Short description: RF Implementation Flow in deep sub-micron CMOS technology. The 5-day Advanced RF Implementation Flow course will start with a short overview of the RF 90nm IC process flow, it will cover modelling issues, microwave passive component design and simulation, testing and microwave measurements, mismatch modelling and simulation, mixed-modes SoC design and simulation, analog and RF cell trimming using digital functions, 90 nm design verification, circuit packaging and ESD-protection.

Contact: IDESA: idesa@rl.ac.uk ** http://www.idesa-training.org/

Course Booking website: http://www.idesa.rl.ac.uk

Seminarium

Publicerad: 2010-02-01

På fredag kl 14.15-15.00 kommer Professor Ari Sihvola, Aalto University School of Science and Technology, Helsinki, Finland att hålla ett seminarium med titeln: ” Varieties of boundary conditions in electromagnetics” i E:3139.