Thin Film Plate Acoustic Resonators for Frequency Control and Sensing Applications
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
The recent development of the commercially viable thin film electro-acoustic technology has triggered a growing interest in the research of plate guided wave or Lamb wave components owing to their unique characteristics. In the present thesis i) an experimental study of the thin film plate resonators (FPAR) performance operating on the lowest symmetrical Lamb wave (S0) propagating in highly textured AlN membranes versus a variety of design parameters has been performed. The S0 mode is excited through an Interdigital Transducer and confined within the structure by means of reflection from metal strip gratings. Devices operating in the vicinity of the stop-band center exhibiting a Q-value of up to 3000 at a frequency around 900MHz have been demonstrated. Temperature compensation of this type of devices has been studied theoretically and successfully realized experimentally for the first time. Further, integrated circuit-compatible S0 Lamb based two-port FPAR stabilized oscillators exhibiting phase noise of -92 dBc/Hz at 1 kHz frequency offset with feasible thermal noise floor below -180 dBc/Hz have been tested under high power for a couple of weeks. More specifically, the FPARs under test have been running without any performance degradation at up to 27 dBm loop power. Further, the S0 mode was experimentally demonstrated to be highly mass and pressure sensitive as well as suitable for in-liquid operation, which together with low phase noise and high Q makes it very suitable for sensor applications; ii) research in view of FPARs operating on other types of Lamb waves as well as novel operation principles has been initiated. In this work, first results on the design, fabrication and characterization of two novel type resonators: The Zero Group Velocity Resonators (ZGVR) and The Intermode-Coupled Thin Film Plate Acoustic Resonators (IC-FPAR), exploiting new principles of operation have been successfully demonstrated. The former exploits the intrinsic zero group velocity feature of the S1 Lamb mode for certain combination of design parameters while the latter takes advantage of the intermode interaction (involving scattering) between S0 and A1 Lamb modes through specially designed metal strip gratings (couplers). Thus both type of resonators operate on principles of confining energy under IDT other than reflection.
Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2012. , 80 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 959
Electro-Acoustics, FPAR, Lamb waves, aluminium nitride, interdigital transducer, phase noise, temperature compensation, power handling, sensitivity, zero group velocity, intermode coupling
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject Engineering Science with specialization in Electronics; Engineering Science with specialization in Microsystems Technology
IdentifiersURN: urn:nbn:se:uu:diva-178592ISBN: 978-91-554-8437-8OAI: oai:DiVA.org:uu-178592DiVA: diva2:543908
2012-09-28, Polhemsalen, Ångströmlaboratoriet, Läggerhyddsvägen 1, Uppsala, 09:15 (English)
Iborra, Enrique, Prof.
Yantchev, Ventsislav, Dr.Katardjiev, Ilja, Prof.
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