Abstract:
In recent years we have witnessed wireless revolution which has been fueled with never quenching desire for anywhere anytime communication and access to data. Miniaturized low-power electronics and wireless devices are the key enabling components of the wireless revolution. As we go forward there is still significant desire to further reduce the size, lower the power, and improve the data rate provided by such systems. In addition to the conventional wireless applications, the emergence of robotics and the need for networking robots together and their surrounding infrastructures as well as interfacing them with human will require further innovation and improvement of wireless systems. For such application, antennas still constitute a major bottleneck in terms of size, bandwidth, efficiency, as well as frequency, polarization and radiation pattern agility and diversity. For many terrestrial communication and for other near earth wave propagation applications, vertical polarization is preferred as the propagation path loss is far lower than any other polarization configurations. Traditional dipole and monopole antennas are large and are non-conformal to mobile and small wireless devices and therefore, low profile small antennas with vertical polarization are needed to achieve much lower propagation path loss. Conventional approaches to reduce the height of monopole antennas cause significant drop in efficiency and polarization purity. Different miniaturization techniques are presented to achieve miniaturized vertically polarized antennas with height as low as λ/300. Different applications requiring such low profile antennas will also be discussed. For radiation diversity, the design and performance of miniaturized omnidirectional horizontally polarized and circularly polarized antennas are presented as well. Finally for small receiving antennas we consider a concept of wideband operation by connecting the antenna to a high impedance receiver and show that such receivers can outperform (in terms of output S/N) the same antenna had it been impedance matched.
Biography:
Kamal Sarabandi (S’87-M’90-SM’92-F’00) is the Fawwaz T. Ulaby Distinguished University Professor and the Rufus S. Teesdale Endowed Professor of Engineering at The University of Michigan. His research areas of interest include microwave and millimeter-wave radar remote sensing, Meta-materials, electromagnetic wave propagation, antenna miniaturization, and bio-electromagnetics. Professor Sarabandi has supervised 61 Ph.D. and numerous Masters students and postdoctoral fellows. He has published many book chapters, more than 320 papers in refereed journals, and more than 770 conference papers. He, together with his students, are recipients of 35 paper awards. Dr. Sarabandi served as a member of NASA Advisory Council for two consecutive terms from 2006-2010 and served as the President of the IEEE Geoscience and Remote Sensing Society (2015-2016). He is the past Chair of Commission F of USNC/URSI and serving as member of the AdCom for the IEEE Antennas and Propagation Society. He led the Center for Microelectronics and Sensors funded by the Army Research Laboratory (2008-2018) and is leading the Center of Excellence in Microwave Sensor Technology. His contributions to the field of electromagnetics have been recognized by many awards including Humboldt Research Award, the IEEE GRSS Distinguished Achievement Award, the IEEE Judith A. Resnik medal, the IEEE GRSS Education Award, NASA Group Achievement Award, and many other wards from the University of Michigan. He is a Fellow of the IEEE, a Fellow of the American Association for the Advancement of Science (AAAS), and a Fellow of the National Academy of Inventors. He is a member of the National Academy of Engineering.
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