1F – Multilayered structures for new generation of SAW devices with improved performance: fundamentals, wave characteristics and applications

Title1F - Multilayered structures for new generation of SAW devices with improved performance: fundamentals, wave characteristics and applications
InstructorNatalya F. Naumenko, National University of Science and Technology, Moscow, Russia
Overview of topics covered

  • Basics of acoustic wave propagation in layered structures, main types of waves

  • Matrix formalism and its application to analysis of acoustic waves in multilayered structures

  • Selection of materials for layered structures: main principles

  • SAW dispersion and spurious modes in resonators built on layered structures

  • Wave nature, loss mechanisms and Q-factors: visualization of acoustic waves

  • Multilayered structures for SAW resonators with improved performance: overview

  • SAW resonators based on thin LiNbO3 or LiTaO3 plates bonded to a supporting substrate, as an example: optimization and potential applications

TimeMonday, October 22
AbstractAcoustic wave resonators with low losses, high quality (Q) factor and improved temperature characteristics are strongly required for the next generation of SAW devices used in mobile communication systems with very narrow gaps between the specified frequency bands. Multilayered structures combining materials with different properties in one stack can satisfy these requirements and can be considered as a new class of substrate materials for SAW devices. Proper selection of materials and orientations to be combined, as well as optimization of the number and thicknesses of the layers, requires understanding of fundamentals of wave propagation in layered structures, main types of acoustic waves, which can be generated in these structures by interdigital transducers, methods of their theoretical and numerical investigation and other important aspects. The main goal of this short course is to provide a guidance to SAW designers and researchers, who work or plan to work with multilayered structures as new materials for resonator SAW filters or SAW sensors. In addition to basics of wave propagation in different types of multilayered structures, a special attention will be paid to methods of improvement of Q-factor and suppression of spurious modes in SAW resonators. An overview of the previously reported and promising layered and multilayered structures will be provided, with summary of achievable characteristics and examples of applications in SAW devices.
Short CV of Instructor Natalya F. Naumenko received M.Sc. and Ph.D. degrees in the physics of dielectrics and semiconductors from the Moscow Steel and Alloys Institute (today National University of Science and Technology, NUST) in 1979 and 1984, respectively. Since 1979 she works as a researcher in SAW device design, first in the Radio-Engineering Institute, Moscow, and since 1990 in NUST. From 1995 to 2011, Dr. Naumenko was also a consultant for the company TriQuint Semiconductors (SAWTEK Inc. before 2001, today merged with Qorvo), in Apopka, FL. She was engaged in modeling and development of advanced software for improvement of SAW device performance and investigation of new materials for SAW devices. From 2011 to 2018, she also performed research projects for TDK-EPCOS, Germany, CTR, Austria and TST, Taiwan. Dr. Naumenko is the author of sixteen issued U.S. patents on the optimal substrate orientations for SAW devices, including the patent on the optimal cut of langasite, which is widely used today in SAW filters and sensors operating at high temperatures. She is the author of more than 90 publications in SAW material research. Her current research interests include investigation of novel SAW materials, such as multilayered substrates for SAW filters and sensors, and development of improved simulation tools for design of SAW and BAW devices, including resonator SAW filters, delay lines and wireless SAW sensors. Since 2011 Dr. Naumenko is member of the Technical Program Committee of the IEEE Ultrasonic Symposium. In 2016, Dr. Naumenko and Prof. Tao Han, from Shanghai University, gave a joint short course on wireless SAW sensors for harsh environment applications at the IUS-2016 in Tours, France.