Title :
Analysis of the natural single phase unidirectional SAW transducer
Author :
Thorvaldsson, Thor
Author_Institution :
Inst. for Field & High Frequency Tech., ETH, Zurich, Switzerland
Abstract :
The calculation of fundamental parameters needed for the analysis of a natural single-phase unidirectional transducer (NSPUDT) is reported. Analytical forms for the NSPUDT parameters on arbitrary crystal cuts are given in terms of material constants and electrode geometry. The acoustic-wave velocity, electromechanical-coupling parameter, power-flow angle, static capacitance, transduction coefficient, and reflection from a single strip due to both electrical and mechanical perturbations are found as a function of the propagation angle on ST quartz. The coupling-of-nodes (COM) theory is then used to analyze a practical NSPUDT device. From solutions of the coupled mode equations, the characteristics of radiation admittance and insertion loss are found. The COM-model is verified by comparison with measurements of a device built on an unconventional orientation on ST quartz
Keywords :
acoustic wave reflection; acoustic wave velocity; capacitance; surface acoustic wave devices; ultrasonic transducers; ST quartz; acoustic-wave velocity; admittance; coupling-of-nodes; electromechanical-coupling parameter; fundamental parameters; insertion loss; natural single phase unidirectional SAW transducer; power-flow angle; reflection; static capacitance; transduction coefficient; Acoustic propagation; Acoustic reflection; Acoustic transducers; Capacitance; Crystalline materials; Electrodes; Equations; Geometry; Strips; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 1989. Proceedings., IEEE 1989
Conference_Location :
Montreal, Que.
DOI :
10.1109/ULTSYM.1989.66964
