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Aerospace and Electronic Systems Society [AES010]
June 10 meeting Rescheduled from May 15
Microwave Theory and Techniques and Aerospace and Electronic Systems Societies
6:00 PM, 8 May
Power Amplifier Challenges for Next Generation Handsets
Douglas A. Teeter, Ph.D., Principal Engineer/Engineering Group Leader, RF Micro Devices, 296 Concord Road, Billerica, MA 01821
Cell phones are the highest volume product in consumer electronics. Today’s cell phone is used for much more than just voice communication. Many features including color displays, cameras, games, streaming video, internet, and MP3 players have been added to phones. These features consume more energy yet battery storage capacity has not been able to keep up. Therefore, increased pressure has been placed on component suppliers to develop linear power amplifiers with reduced average current consumption to bridge the gap between battery capacity and energy demand.
This seminar will begin by giving a brief overview of trends and challenges faced by the RF industry followed by a discussion of key concepts used in the design of power amplifiers with complex modulation schemes including WCDMA, HSPA, and OFDMA. Much of the presentation will focus on major determinants of linear power amplifier efficiency. Use of modulation schemes with a high peak to average ratio combined with typical operation 30 dB below saturation results in the power amplifier operating very inefficiently. The challenge for PA designers is to develop techniques which reduce average current consumption without degrading amplifier performance, increasing size, or adding cost. Several approaches to address this problem will be compared. During the presentation, important concepts necessary for power amplifier development will be explained.
Doug Teeter received his BS degree from Virginia Polytechnic Institute and State University, Blacksburg, in 1987 and the MS and Ph.D. degrees from the University of Michigan, Ann Arbor, in 1988 and 1992, all in electrical engineering. From 1992 to 2000, he worked in the research group of Raytheon’s Advanced Device Center. His work focused on developing power HBT and PHEMT devices and circuits for high efficiency MMIC power amplifiers. He also led Raytheon’s model development group which was responsible for developing HBT and PHEMT device models, extraction techniques, and measurement systems.
Since 2000, he has been working at RF Micro Devices, where he has been involved with the design and development of power amplifiers and front end modules for handsets. During much of this time, he has been the technical lead for numerous linear power amplifier programs. His team’s engineering efforts have included development of high efficiency CDMA, WCDMA, and WiMax linear power amplifiers, ESD improvement, and enhanced back off efficiency techniques. He currently leads the Technology Platform group at the Boston Design Center. Over the past 8 years, he and his team’s power amplifiers have shipped in over 100 million handsets.
This is a joint meeting sponsored by MTT and AES. The meeting will be held at the Lincoln Laboratory Cafeteria in Lexington, MA. Refreshments will be served at 5:30; the talk will begin at 6:00 pm. The talk is open to the general public.
Direction to Lincoln Laboratory Cafeteria from points north: Take I-95/128 south to exit 31B, Routes 4 & 225 towards Bedford. Stay in right lane and use the right turning lane (0.3 miles) to access Hartwell Ave at first traffic light. Follow Hartwell Ave to the end; take a left onto Wood Street (just before the AFB gate). Lincoln Laboratory entrance is 0.5 miles on right. The entrance to the cafeteria is on the lower level left of the main entrance.
From points south: Take I-95/128 north to exit 30B, Route 2A west. Turn right on to Mass Ave (~0.4 miles). Turn left on to Wood Street (~0.4 miles) Lincoln Laboratory Wood Street entrance is 1 mile on left. The entrance to the cafeteria is on the lower level to the left of the main entrance.
For more information contact: Grace Chu, Tyco Electronics, email: chus@tycoelectronics.com; Jeremy Muldavin, MIT Lincoln Laboratory, email: Muldavin@ll.mit.edu, and Eli Brookner, Raytheon, email: eli_brookner@raytheon.com
Aerospace and Electronic Systems, Antennas and Propagation, and Signal Processing Societies
5:30 PM Refreshments; 6:00 PM Talk; June 10 (Rescheduled from May 15)
Space-Time Adaptive Processing for Heterogeneous Radar Clutter Scenarios
Dr. Muralidhar Rangaswamy, Air Force Research Laboratory Sensors Directorate
Early contributions of Howells, Applebaum, and Widrow on adaptive arrays will be briefly reviewed. Sample Matrix Inversion (SMI) method and its variants from the standpoint of CFAR and training data support for covariance matrix estimation will be presented. Candidate reduced-dimension methods will be introduced. Problems encountered in covariance estimation on account of heterogeneous training data and ameliorating solutions from phenomenological, systems and statistical perspective and resulting impact on STAP algorithm performance will be featured. Statistical and ad-hoc techniques for characterizing heterogeneous training data will be discussed. The resulting impact on STAP performance will be presented using simulated and measured data. Some attention will be devoted to recent advances from knowledge based STAP.
Muralidhar Rangaswamy received the Ph.D. degree in electrical engineering from Syracuse University, Syracuse, NY, in 1992.
He is presently a Senior Electronics Engineer at the Sensors Directorate of the Air Force Research Laboratory (AFRL), Hanscom Air Force Base, MA. Prior to this, he has held industrial and academic appointments. His research interests include radar signal processing, spectrum estimation, modeling non-Gaussian interference phenomena, and statistical communication theory. He has co-authored more than 70 refereed journal and conference record papers in the areas of his research interests. Additionally, he is a contributor to three books and is a co-inventor on two U.S. patents.
Dr. Rangaswamy received the 2004 Fred Nathanson Memorial Radar Award from the IEEE Aerospace and Electronics Systems Society, the 2006 Distinguished Member award from the IEEE Boston Section, and the 2005 Charles Ryan Basic Research Award from the Sensors Directorate of AFRL, in addition to 20 AFRL scientific achievement awards.
Directions to MIT Lincoln Laboratory:
The meeting will be held at the MIT Lincoln Laboratory Cafeteria in Lexington, MA. Refreshments will be served at 5:30; the talk will begin at 6:00 pm. The talk is open to the general public. Dinner at a local restaurant will follow for all those interested in continuing conversations with the speaker.
Directions to Lincoln Laboratory Cafeteria from points north: Take I-95/128 south to exit 31B, Routes 4 & 225 towards Bedford. Stay in right lane and use the right turning lane (0.3 miles) to access Hartwell Ave at first traffic light. Follow Hartwell Ave to the end; take a left onto Wood Street (just before the AFB gate). Lincoln Laboratory entrance is 0.5 miles on right. The entrance to the cafeteria is on the lower level left of the main entrance.
From points south: Take I-95/128 north to exit 30B, Route 2A west. Turn right on to Mass Ave (~0.4 miles). Turn left on to Wood Street (~0.4 miles) Lincoln Laboratory Wood Street entrance is 1 mile on left. The entrance to the cafeteria is on the lower level to the left of the main entrance.
For more information, contact Brad Perry, 781-981-0861, bperry@ll.mit.edu (AP-S Boston Section Chair)
Microwave Theory and Techniques, Aerospace and Electronic Systems and Antennas & Propagation Societies
6:00 PM, Monday, 23 June
Three-Dimensional Micromachining for Integrated Microwave and Millimeter Wave Systems
J. Robert Reid, Ph.D., Research Scientist, Air Force Research Laboratory, 80 Scott Dr., Hanscom AFB, MA
The demand for wireless services such as high data rate communications, non-invasive detection of concealed weapons, and high resolution radar is pushing designers to develop highly integrated systems operating at frequencies above 10 GHz. Unfortunately, designing highly integrated RF systems at these frequencies is very challenging due to tight fabrication tolerances, interconnection losses, and signal cross talk. Three dimensional metal micromachining processes have now developed to a point where they offer a solution. Using these processes, passive microwave and millimeter-wave components such as transmission lines, routing networks, and filters can be realized with exceptional performance. Indeed with three dimensional micromachining, it is possible to fabricate highly complex systems such as beam formers in 10% of the volume required using traditional approaches.
This seminar will cover the current state of the art for three dimensional metal micromachining of microwave and millimeter-wave components. The talk will begin with an overview of the two most available processes: EFAB and Polystrata. Next, the presentation will provide details on the realization and performance of transmission lines, couplers, and filters. Finally, the advantages and disadvantages of the technology and competing fabrication approaches will be discussed.
Dr. J. Robert (Rob) Reid received his BSEE from Duke University in 1992 and his MSEE and PhD degrees from the Air Force Institute of Technology (AFIT) in 1993 and 1996 respectively. After graduating from AFIT, he took a position with the Rome Laboratory (now the Air Force Research Laboratory) where he leads a team focused on applying micromachining and MEMS to front end antenna technology. His current research interests include RF MEMS switches and variable capacitors, integrated transmission lines and routing networks, microwave and millimeter-wave filters, and micro-robotics.
Dr. Reid is a member of Sigma Xi and the IEEE. He serves on the Microwave Theory and Techniques (MTT) Society RF MEMS technical coordinating committee and was chosen to be on the MTT speakers bureau. He has received numerous awards including the 2005 Sigma Xi, Northeast Region Young Investigator Award and the 2007 Sensors Directorate Samuel L. Burka Award.
This is a joint meeting sponsored by MTT, AES, and AP and will be held at the Lincoln Laboratory Cafeteria in Lexington, MA. Refreshments will be served at 5:30; the talk will begin at 6:00 pm. The talk is open to the general public.
Direction to Lincoln Laboratory Cafeteria from points north: Take I-95/128 south to exit 31B, Routes 4 & 225 towards Bedford. Stay in right lane and use the right turning lane (0.3 miles) to access Hartwell Ave at first traffic light. Follow Hartwell Ave to the end; take a left onto Wood Street (just before the AFB gate). Lincoln Laboratory entrance is 0.5 miles on right. The entrance to the cafeteria is on the lower level left of the main entrance.
From points south: Take I-95/128 north to exit 30B, Route 2A west. Turn right on to Mass Ave (~0.4 miles). Turn left on to Wood Street (~0.4 miles) Lincoln Laboratory Wood Street entrance is 1 mile on left. The entrance to the cafeteria is on the lower level to the left of the main entrance
For more information contact: Grace Chu, Tyco Electronics, email: chus@tycoelectronics.com; Jeremy Muldavin, MIT Lincoln Laboratory, email: Muldavin@ll.mit.edu, Eli Brookner, Raytheon, email: eli_brookner@raytheon.com, and Bradley Perry, MIT Lincoln Laboratory, email: bperry@ll.mit.edu
Copyright © 2008 IEEE Boston Section.
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Maintained by R M Stelting
Updated: May 13, 2008.