Current Research

    The research of Professor Yang’s group is on frequency stability of piezoelectric crystal resonators under the support of the Army Research Office. Piezoelectric resonators are essential components for radios, phones, satellites, sensors and other equipment for time keeping, control, and telecommunication. They are usually made from quartz. Recently, new single crystals of langasite (La₃Ga₅SiO₁₄) and certain of its isomorphs (langanite and langatate) have shown great promise as future materials for piezoelectric resonators. The operating frequency of piezoelectric resonators can be affected by various environmental effects like temperature change and accelerations which are relevant when resonators are mounted on moving objects. The study of resonator frequency stability requires a nonlinear formulation. Nonlinear material constants of new piezoelectric crystals are being measured and are used in frequency stability analysis of resonators.

Recent Key Publications

J. S. Yang and H. Y. Fang, “A New Ceramic Tube Piezoelectric Gyroscope”, Sensors and Actuators A 107, 42-49, 2003.

J. S. Yang, X. Zhang, J. A. Kosinski and R. A. Pastore, Jr., “Thickness-Shear Vibrations of a Quartz Plate under Time-Dependent Biasing Deformations”, IEEE Trans. on Ultrasonics, Ferroelectrics, and Frequency Control 50, 1114-1123 (2003).

J. S. Yang and H. Y. Fang, “A Piezoelectric Gyroscope Based on Extensional Vibrations of Rods”, Intern. J. Appl. Electromagnetics and Mechanics 17, 289-300 (2003).

J. S. Yang, X. M. Yang, J. A. Turner, J. A. Kosinski and R. A. Pastore, Jr., “Two-Dimensional Equations for Electroelastic Plates with Relatively Large Shear Deformations”, IEEE Trans. Ultrasonics, Ferroelectrics, and Frequency Control 50, 765-772 (2003).

Y. T. Hu, X. Zhang, J. S. Yang and Q. Jiang, “Transmitting Electric Energy through a Metal Wall by Acoustic Waves using Piezoelectric Transducers”, IEEE Trans. on Ultrasonics, Ferroelectrics, and Frequency Control 50, 773-781 (2003).

J. S. Yang, “Equations for Small Fields Superposed on Finite Biasing Fields in a Thermoelectroelastic Body”, IEEE Trans. on Ultrasonics, Ferroelectrics, and Frequency Control 50, 187-192 (2003).

J. S. Yang and X. Zhang, “Vibrations of a Constrained Crystal Plate under a Thermal Bias”, J. Thermal Stresses 26, 467-477 (2003).

Y. T. Hu, J. S. Yang and Q. Jiang, “Analysis of 2D Piezoelectric Strips and Semi-Strips”, ZAMP 54, 149-159 (2003).