Title :
Suppression of transverse waveguide modes for SAW resonators with Pt and Pt/Rh/ZrO2 electrodes
Author :
Meulendyk, B.J. ; da Cunha, M. Pereira
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Maine, Orono, ME, USA
Abstract :
In this work, spurious transverse waveguide modes were suppressed from the frequency responses of Pt-electrode resonators on ST-X quartz [0°, 132.75°, 0°] and Pt- and Pt/Rh/ZrO2-electrode resonators on LGS [0°, 144°, 24°] through the design of the gratings, aperture, and transducers´ active area. In particular, it will be shown that conventional shorted gratings cannot be used with Pt or Pt/Rh/ZrO2 electrodes, since the velocity discontinuity between the grating and the bus bar leaks energy from the active area. Scalar potential theory is utilized to adjust the ratio of a transducer´s active area to the total aperture, such that higher-order transverse waveguide resonances are filtered from the frequency response.
Keywords :
acoustic transducers; acoustic waveguides; electrodes; frequency response; platinum; rhodium; surface acoustic wave resonators; zirconium compounds; Pt-Rh-ZrO2; SAW resonator; aperture design; electrode resonator; frequency response; grating design; scalar potential theory; transducer active area design; transverse waveguide mode suppression; velocity discontinuity; Apertures; Electrodes; Gratings; Insertion loss; Resonance; Resonator filters; Surface acoustic waves; Transducers; Virtual manufacturing; Waveguide theory; LGS; Pt electrodes; Pt/Rh/ZrO2 electodes; quartz; transverse waveguide mode suppression;
Conference_Titel :
Ultrasonics Symposium (IUS), 2009 IEEE International
Conference_Location :
Rome
Print_ISBN :
978-1-4244-4389-5
Electronic_ISBN :
1948-5719
DOI :
10.1109/ULTSYM.2009.5441767
