Tuesday, April 17, 2012

Sign up now, MIT short-course: Build a Phased Array Radar System




Are you interested in learning about phased array radar systems by building and testing your own?
MIT Professional Education is offering a unique course in the design, fabrication, and test of a laptop-based digital phased array radar sensor capable of ground moving target imaging (GMTI). Lectures will be presented on the topics of applied electromagnetics, antennas, RF design, analog circuits, radar system modeling, and digital signal processing while at the same time you build your own phased array radar system and perform field experiments. Each student will receive a radar kit, designed by MIT Lincoln Laboratory staff, and a course pack.


Wednesday, April 4, 2012

Low-Cost Ultrawideband (UWB) Phased Array Antennas - Importance, Challenges and Inroads

We are pleased to announce that Prof. Marinos N. Vouvakis from University of Massachusetts Amherst will present to the Microwave Theory & Techniques and the Antennas & Propagation Societies On April 19 at 6pm

Abstract:

The two prevailing trends in modern communication and sensing system technologies are increased information throughput or functionality, and smaller sizes. From the physical-layer electronics perspective such as RF/microwave engineering, these trends translate into hardware with wider bandwidths and higher frequencies of operation. Yet, when it comes to the design of antenna arrays, that are necessary in every wireless communications, stand-off sensing or electronic countermeasure, these treads are in direct conflict with one another. Ultrawideband (UWB) phased arrays are significantly more challenging to design and build than their narrowband counterparts, whereas manufacturability constraints above X-band severely limit the effectiveness of bandwidth enhancement methods. These technical challenges are reflected in the skyrocketing price-tags of extremely high frequency (EHF) UWB arrays, and their limited use to select military or security applications.

Established UWB phased array technologies such as the Vivaldi array, or the fragmented aperture array or Monk’s current sheet array are either too complicated to build at EHFs, or require performance-limiting feeding methods to integrate with the rest of the phased array system, or cannot be easily installed or maintained due to lack of aperture modularity. This seminar will introduce a novel low-cost UWB phased array, the planar ultrawideband modular antenna (PUMA) that overcomes all these limitations. The PUMA array is extremely simple, making it easy to build with standard low-cost microwave fabrication techniques even above Ku-band, the key comes from its novel direct-feeding scheme that avoids altogether external baluns and elaborate feed-line shielding without performance degradation. Moreover, the carefully laid-out PUMA aperture allows for modular manufacturing with tiled assemble, leading to certain cost, installation, maintenance and robustness benefits.

After a brief introduction in ultrawideband/multifunctional systems and phased arrays, the talk will focus on the basic PUMA array topology, variations, principles of operation and modeling, and design and manufacturing approaches. The design, fabrication and measurements of an exemplary 7-21GHz PUMA design will be used to concretely demonstrate the technology. Several newer computational prototypes will be presented that operate at higher than 6:1 bandwidth. Important phased array aspects such as impedance matching (VSWR), coupling, radiation pattern, wide angle scanning, polarization purity, and fabrication cost will be used to scrutinize the quality of the designs. Time permitting, a short glimpse of the advanced in-house numerical modeling techniques, used to design the full finite PUMA array will be given.

Bio:

Dr. Marinos N. Vouvakis (S'99, M’05) is an Associate Professor of Electrical and Computer Engineering (ECE) at the University of Massachusetts Amherst, where he conducts research and teaching in the areas of microwave and antenna engineering, and computational electromagnetics. Dr. Vouvakis received the Diploma degree in ECE from the Democritus University of Thrace (DUTH), Xanthi, Hellas, in 1999, he holds a M.S. from Arizona State University (ASU), Tempe, AZ and a PhD from The Ohio State University (OSU), Columbus OH, both in ECE. Since 2005 he is with the UMass ECE faculty as a member of the Center for Advanced Sensor and Communication Antennas (CASCA) and the Antennas and Propagation Laboratory (APLab). His main research interests are in computational electromagnetics (CEM), where he is known for his contributions on domain decomposition methods, finite element methods, fast integral equation methods, hybrid methods, and model order reduction, all in the context of antennas, electromagnetic scattering, microwave devices, EMC/EMI and optical lithography modeling. Recently he started working on experimental research in antennas and the design of ultrawideband and low-profile phased arrays.

Meeting will be held at MIT Lincoln Laboratory A-Café, 244 Wood Street, Lexington, MA. For directions please see: http://www.ll.mit.edu/about/map.html

Date & Time: April 19 at 6pm

Refreshments served at 5:30 PM

Solution of Extremely Large Integral Equations in Computational Electromagnetics (with Fast Algorithms and Parallel Computing)


We are pleased to announce that Distinguished Lecturer Levent Gürel is flying out from Turkey to speak to the IEEE AP-S Society of Boston on April 17 at 6pm


Abstract:

Accurate simulations of real-life electromagnetics problems with integral equations require the solution of dense matrix equations involving millions of unknowns. Solutions of these extremely large problems cannot be achieved easily, even when using the most powerful computers with state-of-the-art technology. Some of the world’s largest integral-equation problems in computational electromagnetics have been solved at Bilkent University Computational Electromagnetics Research Center (BiLCEM). Most recently, we have achieved the solution of 550,000,000x550,000,000 dense matrix equations! This achievement is an outcome of a multidisciplinary study involving physical understanding of electromagnetics problems, novel parallelization strategies (computer science), constructing parallel clusters (computer architecture), advanced mathematical methods for integral equations, fast solvers, iterative methods, preconditioners, and linear algebra.

In this seminar, following a general introduction to our work in computational electromagnetics, I will continue to present fast and accurate solutions of large-scale electromagnetic modeling problems involving three-dimensional geometries with arbitrary shapes using the multilevel fast multipole algorithm (MLFMA) and parallel MLFMA. Some of the complicated real-life problems (such as, scattering from a realistic aircraft) involve geometries that are larger than 1000 wavelengths. Accurate solutions of such problems can be used as reference data for high-frequency techniques. Solutions of extremely large canonical benchmark problems involving sphere and NASA Almond geometries will be presented, in addition to the solution of complicated objects, such as metamaterial problems, red blood cells, and dielectric photonic crystals. Solving the world's largest computational electromagnetics problems has important implications in terms of obtaining the solution of previously intractable physical, real-life, and scientific problems in various areas, such as (subsurface) scattering, optics, bioelectromagnetics, metamaterials, nanotechnology, remote sensing, etc. For more information, please visit www.cem.bilkent.edu.tr.

Bio:

Prof. Levent Gürel (Fellow of IEEE, ACES, and EMA) is the Director of the Computational Electromagnetics Research Center (BiLCEM) at Bilkent University, Ankara, Turkey. He received the M.S. and Ph.D. degrees from the University of Illinois at Urbana-Champaign (UIUC) in 1988 and 1991, respectively, in electrical and computer engineering. He joined the IBM Thomas J. Watson Research Center, Yorktown Heights, New York, in 1991. Since 1994, he has been a faculty member in the Department of Electrical and Electronics Engineering of the Bilkent University, Ankara, where he is currently a Professor, and a Visiting/Adjunct Professor at UIUC since 2003. Among the recognitions of Prof. Gürel's accomplishments, the two prestigious awards from the Turkish Academy of Sciences (TUBA) in 2002 and the Scientific and Technological Research Council of Turkey (TUBITAK) in 2003 are the most notable. Prof. Gürel is currently serving as an associate editor of Radio Science, IEEE Antennas and Wireless Propagation Letters (AWPL), Journal of Electromagnetic Waves and Applications (JEMWA), and Progress in Electromagnetics Research (PIER). He is named an IEEE Distinguished Lecturer for 2011-2013 and invited to address the 2011 ACES Conference as a Plenary Speaker.

Meeting will be held at MIT Lincoln Laboratory A-Café, 244 Wood Street, Lexington, MA. For directions please see: http://www.ll.mit.edu/about/map.html

Date & Time: April 17 at 6pm

Refreshments served at 5:30 PM

For more information please check out:

http://www.ieeeboston.org/org/subgroups/antennas_propagation.html

Sunday, April 1, 2012

Sign up now: MIT Build a Radar Short-Course




COURSE SUMMARY

Are you interested in learning about radar by building and testing your own imaging radar system?
MIT Professional Education is offering a course in the design, fabrication, and test of a laptop-based radar sensor capable of measuring Doppler and range and forming synthetic aperture radar (SAR) imagery. Lectures will be presented on the topics of applied electromagnetics, antennas, RF design, analog circuits, and digital signal processing while at the same time you build your own radar system and perform field experiments. Each student will receive a radar kit, designed by MIT Lincoln Laboratory staff, and a course pack.