Advancements in and Radar Technology Enabled by Electromagnetic Bandgap and Metasurfaces

Kamal Sarabandi, The University of Michigan, Ann Arbor, MI, USA

Abstract: Electromagnetics is one of the greatest achievements of physics in the 19th century. Despite its long history of development, due to its fundamental nature and broad base, research in applied electromagnetics is still vital and going strong. In recent years electromagnetic has played a major role in wide range of disciplines, including communications, remote sensing of environment, defense, medicine, etc., with significant societal impact. The growth and vitality in EM research has been fueled by an increasing demand for anytime/anywhere information and data, security, and global monitoring of the environment, as well as significant advancements in other related science and engineering disciplines particularly in computers and materials. Introduction of new engineered materials has opened a door for much innovation needed to propel the wireless and radar technologies in many applications. This lecture will provide an overview of applications electromagnetic bandgap metamaterials and metasurfaces developed in Professor Sarabandi’s group. In specifics, the applications of EM bandgap structures for implementation of super‐directive arrays and super‐miniaturized full‐ duplex radio repeaters will be presented. Substrate mode suppression created by artificial bandgap materials allows for placement of small antennas in close proximity of each other while providing a highly level of electromagnetic isolation. Also some novel metasurfaces such as reactive impedance surfaces for miniaturization and miniaturized‐element‐frequency‐selective‐surfaces (MEFSS) as high‐order spatial filtering radomes, transparent ground planes, non‐absorptive radar‐cross‐section reducer EM skin, will be presented to highlight some of the advancements enabled by metasurfaces. Using exact image theory it is shown that the image of electric current over reactive impedance surfaces is a distributed current in complex coordinate space leading to much reduced interaction of the source and its image, giving rise to much higher bandwidth compared to commonly used perfect magnetic surfaces. Dimensions of the constitutive elements of these surfaces are much smaller than the wavelength, their interaction with EM waves is localized and their responses are free of harmonic.

Biographical Sketch: Kamal Sarabandi (Fellow of IEEE and AAAS) is currently Director of the Radiation Laboratory and the Rufus S. Teesdale endowed Professor of Engineering in the Department of and Computer Science. Over the past 30 years his research has been focused on applied electromagnetics and has made significant contributions to science and technology of and millimeter‐wave radar systems, microwave remote sensing, metamaterials, antennas, communication channel modeling, and microwave sensors. He has graduated 51 Ph.D. and supervised numerous post‐doctoral students. He has served as the Principal Investigator on many projects sponsored by NASA, JPL, ARO, ONR, ARL, NSF, DARPA, and a large number of industries. He led the Center for Microelectronics and Sensors sponsored by the Army Research Laboratory under the Micro‐ Autonomous Systems and Technology (MAST) Collaborative Technology Alliance (CTA) program from 2008 to 2018. He is now leading a newly established center in Microwave Sensor Technology funded by King Abdulaziz City for Science and Technology (KACST). He has published many book chapters and more than 290 papers in refereed journals and more than 680 conference papers. Dr. Sarabandi served as a member of NASA Advisory Council appointed by the NASA Administrator (2006‐2010) and served as the President of the IEEE Geoscience and Remote Sensing Society in 2015 and 2016. He is recipient of many awards including IEEE Judith A. Resnik Award, IEEE GRSS Distinguished Achievement Award, University of Michigan Distinguished Achievement Award, Humboldt Research Award, NASA Group Achievement Award, and 28 paper awards. 7