2013 IEEE International Symposium on Phased Array Systems & Technology
15 - 18 October 2013 Waltham, Massachusetts USA
Tutorial: Thermal Management of Active Electronically Scanned Arrays
Thermal Management of Active Electronically Scanned ArraysDr. Avram Bar-Cohen, DARPA, Dr. John Albrecht, Michigan State, Mr. David Altman, Raytheon, Dr. Joseph Maurer, Booz Allen Hamilton. Tutorial Overview:The performance characteristics of electronically-scanned RF arrays are constrained by the thermal management technology incorporated into the design of the MMIC, T/R module, and RF system. The progressive application of more advanced thermal management techniques, materials, and modeling approaches have facilitated the rapid evolution of AESA technology but continued reliance on state-of-the-art techniques may compromise the ability to fully exploit the benefits of emerging wide bandgap MMICs for traditional, as well as unconventional, AESA form-factors and applications.This tutorial will open with a description of the thermal management needs of RF arrays and the performance enhancement that can be achieved through the application of aggressive cooling techniques. Next, the history and state-of-the-art in phased array thermal management, at the MMIC, T/R, and system levels will be described. Following a short break, attention will turn to a brief review of heat transfer principles and modeling equations for conductive, convective, and evaporative cooling. Next, emerging thermal management techniques, including low resistivity TIMS high conductivity heat spreaders, and use of high conductivity substrates will be described. The tutorial will close with a discussion of the “inward migration” of active AESA cooling and the current focus on the development of “embedded microfluidic cooling” for RF arrays.Presentation Outlines:•Operational Requirements - Dr., John Albrecht, Michigan State•Past and Current Thermal Solutions - Mr. David Altman, Raytheon•Break•Principles of Heat Transfer - Dr. Avram Bar-Cohen, DARPA/MTO•Emerging Thermal Management Techniques - Dr. Joseph Maurer, Booz Allen Hamilton•Thermal Architectures - Dr. Abram Bar-Cohen, DARPA/MTOBiographyAvram Bar-Cohen is a Program Manager in the Microsystems Technology Office of the Defense Advanced Research Projects Agency (DARPA), Arlington, VA, with interests in thermal management and energy conversion technologies. He is serving in this capacity while on leave from his position as a Distinguished University Professor at the University of Maryland, where he most recently also served as the Chair of the Mechanical Engineering Department (2001-2010). Bar-Cohen earned a PhD in Mechanical Engineering from the Massachusetts Institute of Technology and prior to joining Maryland, Bar-Cohen directed the University of Minnesota’s Center for the Development of Technological Leadership and held the Sweatt Chair in Technological Leadership. His publications, lectures, short courses, and research, as well as professional service in ASME and IEEE, have helped to create the scientific foundation for the thermal management of electronic components and systems and pioneered techniques for energy-efficient sustainable design.Dr. Bar-Cohen has received numerous awards, including the prestigious International Centre for Heat and Mass Transfer's 2008 Luikov Medal, ASME’s Heat Transfer Memorial Award (1999), and the IEEE CPMT Society’s Outstanding Sustained Technical Contributions Award (2002). He is among a very select number of ASME Honorary Members and is a Fellow of the IEEE.BiographyJoseph Maurer is a Lead Associate at Booz Allen Hamilton in Arlington, VA and has been supporting DARPA/MTO as a SETA contractor since October 2008. His research interests include the thermal management of RF and computing components, compound semiconductor devices, high speed electronics, and heterogeneous integration. He earned a PhD in Chemical Engineering from the University of Virginia in 2008 with a focus in electrochemical microfabrication and during his time as a Research Assistant spent 8 months as a Guest Researcher at the National Institute of Standards and Technology in Gaithersburg, MD. Dr. Maurer is a member of IEEE and has served as a session co-chair and technical program committee member for CSICS and has co-authored conference abstracts for both CSICS and CS Mantech.BiographyDavid Altman - is a Senior Principal Mechanical Engineer in Raytheon Integrated Defense Systems (IDS) Advanced Technology Programs. David has 11 years of experience designing, developing, analyzing and testing thermal management systems for radar and other high power defense electronics systems. Over this period, David has developed liquid cooling systems, cold plates, heat exchangers and integrated thermal management systems that are employed in fielded Raytheon products. As a member of IDS Advanced Technology Programs, his current work focuses on development of new thermal management and energy system technologies through internal (IR&D) and external (e.g., DARPA/ONR) funding. David holds BS and MS degrees from Rensselaer Polytechnic Institute and Boston University. He has authored or co-authored ten peer reviewed technical publications and holds two US patents, with seven published applications pending. BiographyJohn Albrecht is an Associate Professor of Electrical and Computer Engineering and of Materials Science at Michigan State University, East Lansing, MI, with interests in RF Electronics with a focus on emerging materials and devices. Albrecht earned a PhD in Electrical Engineering from the University of Minnesota and prior to joining MSU served from 2009-2012 as a Program Manager in the DARPA Microsystems Technology Office where he managed projects in the mm-wave phased array, sub-mm wave electronics, and wide band gap semiconductor device areas. Albrecht was at DARPA on assignment from the Air Force Research Laboratory Sensors Directorate which he joined in 2002 and served as Division Technical Advisor for the Aerospace Components and Technology Division from 2006-2007. His career at AFRL ranged from basic research in materials and devices to the oversight of a wide-ranging technical portfolio of intramural and externally funded electronics technologies spanning electronic materials to subsystems and apertures.