The 5G standard promises a revolution in wireless data transfer with Gbps links over kilometers at millimeter-wave frequencies. This is possible using high-gain antenna arrays resulting in “directive communications” between the base-station and the user, either in a phased-array or in a MIMO configuration. A key challenge is the construction and test of low-cost phased-arrays and transceivers at the 5G bands: 24-30 GHz, 36-42 GHz and 57-70 GHz. Prof. Rebeiz will present the progression of phased-array systems from defense-oriented applications to becoming the cornerstone of millimeter-wave commercial 5G systems, and the role of silicon RFICs, built-in-test, and antenna design and calibration, to making this happen.
Gabriel M. Rebeiz is one of the fathers of silicon RFIC phased-arrays. Starting in 2001, Prof. Rebeiz has taken this technology from its infancy to SATCOM phased-arrays, 60 GHz base-station phased-arrays, automotive radar phased-arrays, and now, 28 GHz and 39 GHz 5G systems. He holds a Ph.D. in electrical engineering from the California Institute of Technology (Caltech), and is currently the Wireless Communications Industry Chair Professor at UCSD. He has graduated 90 Ph.D. students and post-docs, has more than 650 IEEE publications, and has received the Microwave Prize twice, both on phased-array topics. In 2016, Prof. Rebeiz was elected to the National Academy of Engineering for his contribution to low-cost phased arrays.
Over more than a decade of research and development, reconfigurable antennas have been characterized and demonstrated in several different closed loop systems. These antennas typically are wavelength-sized single-feed apertures capable of tuning over an octave in frequency, reaching any point on the Poincaré sphere, and steering in two dimensions. Prior to the DARPA RECAP program in 1999, genetic algorithms were used to optimize pixelated or “fragmented aperture” antennas in simulation, i.e. before construction. Since that time, electronically reconfigurable antennas have been optimized in situ using closed-loop measurement systems. This approach produces optimized personalities accounting for variations in manufacturing. Such measurement systems are general purpose and precise but relatively slow. Fortunately, the increasing popularity and availability of software defined radio equipment since 2004 has enabled higher speed closed loop demonstrations taking advantage of baseband processing. The increase in speed and cooperation with radio hardware has enabled real-time closed loop control ranging from multi-mode operation to blind adaptation to propagation channels. This talk describes several systems, results, and demonstrations conducted recently at GTRI.
Dr. Ryan Westafer is a Senior Research Engineer and Chief Scientist of the Electromagnetics Division of the Advanced Concepts Laboratory (ACL) at Georgia Tech Research Institute (GTRI). He received the BS (CMPE), MSECE, and PhD (EE) degrees from Georgia Tech, with a research focus in dispersion engineering of surface waves in piezoelectric phononic crystals for a multiplexed passive RF backscatter sensor. Since joining GTRI, Ryan has supported or led many programs ranging from RF devices to antenna applications. Most recently, he has served as lead engineer of GTRI’s team creating a Reconfigurable Electromagnetic Interface (REI) for the DARPA ACT program. Ryan’s ongoing research interests include optimized W-band apertures and full-wave simulation of time-varying antennas and systems.
Dr. Aubrey Beal received B.E.E., M.S. and PhD degrees in Electrical Engineering from Auburn University in Auburn, AL. He has industry experience in bulk power systems with Southern Company, power electronics for high performance computers with IBM as well as metal detection for biomedical applications. Dr. Beal is a researcher and Electronics Engineer with the U.S. Army Charles M. Bowden Laboratory at Redstone Arsenal, Alabama. His current research interests include nonlinear dynamics and chaos for applications in communications and radar.
Dr. Martin Heimbeck received his M.S. and PhD degrees in Physics and Optical Science and Engineering from The University of Alabama in Huntsville, Huntsville, AL in 2008 and 2016 respectively. Dr. Heimbeck conducts basic and applied research activities at the Charles M. Bowden Research Laboratory in the Army's Aviation & Missile RD&E Center located at Redstone Arsenal, AL, USA. His research interests include millimeter wave research at 60 GHz for communication applications and extremely high frequency (100 - 1000 GHz) research for coherent imaging radar applications including digital holography and computational tomography.
The European Space Agency (ESA) is one of the few space agencies in the world to combine responsibility in nearly all areas of space activity. Covering applications from Space Science, Telecommunication, Earth Observation to Navigation, testing space antennas asks for measurement capabilities in a very broad frequency range and for test objects of very different size. To reduce mass and power on board of satellites and/or interplanetary probes, all space missions are characterized by extremely reduced margin in link budgets and for this reason antenna’s efficiency as well as measurement accuracy are crucial. All the above puts strong constraints on space antenna test ranges and techniques. New domains requiring further development with respect to the state of the art are innovative approaches for efficient antenna and payload RF characterization, radiated high power testing, radiated PIM testing in Near Field with processing to localize the PIM sources, accurate characterization of radiated phase for interferometric instruments and navigation antennas, test techniques for sub-mm wave antenna measurements (e.g. Phaseless Near Field) and characterization of the RF properties of material and processes involved in antenna design. ESA is active in all the above mentioned areas promoting ideas and funding activities. With respect to support to current space missions and their challenges in antenna testing, space industry is facing the problem of accurately characterizing large objects at low frequencies (e.g. BIOMASS, MTG), where measurement capabilities of existing ranges might not be sufficient and leading to the need of elaborating ad hoc verification methodologies. Also, for telecom satellites, moving from single beam to multiple beam antennas, where measurement time increase dramatically, is leading to prohibitive cost of the test campaign and efficient test approaches need to be developed and validated. Moreover, next generation telecom satellite systems are moving from one unique satellite to mega constellations (e.g. OneWeb) where different verification scenarios need to be elaborated to reduce the cost of the system development and deployment. In case of large telecom platforms, there is the need of making available testing facilities with very large quiet zones and complex zero-g devices to allow accurate testing of antenna farms. Alternatively, new, portable, antenna measurement systems to allow unconventional measurements of the large platforms could be utilized (e.g. Airbus PAMS). In more and more application domains (e.g. Earth Observation and Navigation) project teams welcome payload/instrument end-to-end radiated testing, performing quality analysis on the signal radiated by the payload/instrument connected to the antenna. To allow for this, efficient (Near Field) payload test procedures and processing need to be further consolidated. The talk will provide an overview of the above mentioned challenges in space antenna measurements with reference to past and running ESA projects, highlighting state of the art solutions and achievements.
Dr. Luca Salghetti Drioli received the MSc and PhD degrees from the University of Florence, Italy, in 1997 and 2001, respectively, both in electrical engineering. During his PhD coursework, he joined CSELT laboratories in Turin, Italy working on the design and test of frequency selective surfaces for high-gain antennas and focusing on extension and application of the Generalized Admittance Matrix Method to the electromagnetic characterization of complex geometry structures, such as polarizers, and orthomode transducers (OMTs). Further, he spent four months with the Earth Station Operation Center of the European Space Agency (ESA-ESOC) in Darmstadt, Germany, working on the optimization of the deep space antenna for the Rosetta Mission. In 2003 he joined the Antenna and Sub-mm wave section at ESA-ESTEC where is currently supporting the antenna developments in several ESA projects (e.g. GALILEO, BIOMASS). His research interests include waveguide components for feed-systems, numerical and asymptotic methods in electromagnetic scattering and radiation problems, frequency selective surfaces and antennas for navigation applications. From 2006 he is also the coordinator of the course on Antennas for Space Applications organized in the frame of the European School of Antennas. Dr. Salghetti Drioli is supporting the antenna measurement facilities of the Electromagnetic Division of European Space Agency. He was the responsible of the upgrade of the already existing Compact Test Range to an hybrid facility including a near field system in the same anechoic room. He has been leading the GALILEO Satellite Antenna farm test campaign and he is supporting all ‘low frequency’ antenna measurement activities in ESA.