Title :
Amplitude-frequency effect of Y-cut langanite and langatate
Author_Institution :
Res. Dev. & Eng. Center, US Army Commun.-Electron. Command, Fort Monmouth, NJ, USA
Abstract :
Amplitude-frequency effect of a Y-cut langanite (LGN) resonator and a Y-cut langatate (LGT) resonator were measured. The frequency shifts from the baseline frequency with 1 mA were measured as a function of drive currents up to 28 mA. High-drive current shifted the frequency, but it also heated the crystal locally, causing temperature-related frequency changes. The local heat transfer and its influence on the frequency were analyzed. The amplitude-frequency shift was effectively measured, and was not affected by the temperature-related frequency changes. The 3rd, 5th, and 7th overtones (OT´s) were found to behave as soft springs, i.e., resonant frequency decreases as drive current increases. The drive sensitivity coefficients of the 3rd and 5th OT´s are in the vicinity of -2 ppb/mA/sup 2/ for both resonators. The 7th OT´s are higher than the other OT´s: -5/spl sim/- 7 ppb/mA/sup 2/. The lowest drive sensitivity is -1.2 ppb/mA/sup 2/ on the 5th OT of the LGT.
Keywords :
crystal resonators; frequency measurement; gallium compounds; heat transfer; lanthanum compounds; 1 mA; 28 mA; La/sub 3/Ga/sub 5.5/Nb/sub 0.5/O/sub 14/; La/sub 3/Ga/sub 5.5/Nb/sub 0.5/O/sub 14/ langanite; La/sub 3/Ga/sub 5.5/Ta/sub 0.5/O/sub 14/; La/sub 3/Ga/sub 5.5/Ta/sub 0.5/O/sub 14/ langatate; Y-cut langanite resonator; Y-cut langatate resonator; amplitude frequency effect; baseline frequency; drive currents; frequency shifts; local heat transfer; resonant frequency; sensitivity coefficients; temperature related frequency; Acoustic applications; Dielectric materials; Frequency measurement; Heat transfer; Ovens; Piezoelectric materials; Resistors; Resonant frequency; Springs; Testing;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2003.1256309
