Title :
Low TCF Lithium Tantalate contour mode resonators
Author :
Renyuan Wang ; Bhave, Sunil A. ; Bhattacharjee, Kushal
Author_Institution :
OxideMEMS Lab., Cornell Univ., Ithaca, NY, USA
Abstract :
This paper presents for the first time thin-film contour mode resonators (CMR) using Lithium Tantalate (LT). Exploiting the inherent low temperature coefficient of frequency (TCF) of certain acoustic modes in LT, we demonstrate low TCF S0 lamb wave mode CMRs in rotated Y-cut LT thin films. With an electrode configuration using a top interdigitated transducer (IDT) and bottom ground electrode, we fabricated 1-port resonators at 501MHz and 870MHz, and 2-port resonator at 849MHz. These devices exhibit low motional impedance (10-20 Ω), with quality factors as high as 3200. More significantly, a TCF of -20ppm/K is demonstrated from the 1-port devices, while the 2-port device exhibits -16.7ppm/K. These are the lowest TCFs demonstrated to date from an uncompensated thin-film contour mode resonators, making LT thin-film technology a promising candidate for oscillator applications.
Keywords :
UHF resonators; electrochemical electrodes; interdigital transducers; lithium compounds; surface acoustic wave resonators; surface acoustic wave transducers; thin film devices; 1-port resonator; 2-port resonator; IDT; LiTaO3; S0 lamb wave mode CMR; acoustic mode; bottom ground electrode; frequency 501 MHz; frequency 849 MHz; frequency 870 MHz; interdigitated transducer; low TCF lithium tantalate contour mode resonator; resistance 10 ohm to 20 ohm; rotated V-cut LT thin film; temperature coefficient of frequency; thin-film contour mode resonator; Electrodes; Impedance; Lithium niobate; Resonant frequency; Temperature; Wavelength measurement; Lithium Tantalate; contour mode resonator; low temperature coefficient of frequency;
Conference_Titel :
Frequency Control Symposium (FCS), 2014 IEEE International
Conference_Location :
Taipei
DOI :
10.1109/FCS.2014.6859998
