Accession Number : ADD014335

Title :   Method of Making a Transducer from a Boule of Lithium Tetraborate and Transducer so Made.

Descriptive Note : Patent application, Filed 23 Oct 89,

Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON DC

Personal Author(s) : Ballato, Arthur ; Kosinski, John A

Report Date : 23 Oct 1989

Pagination or Media Count : 9

Abstract : The general object of this invention is to provide a transducer characterized by frequency insensitivity to temperature variations. A more particular object of the invention is to provide a transducer in which both the first- and the second- order temperature coefficient of frequency are substantially zero. Another object of the invention is to provide a transducer in which the piezoelectric coupling is large. Still another object of the invention is to provide a transducer in which the piezoelectric coupling is large for thickness shear mode of vibration. The aforementioned objects can be attained by providing a transducer in which Lithium Tetraborate is oriented with respect to its crystallographic axes to form a plate having a doubly rotated orientation of Phi = 17 degs to 21 and theta = 54 degs to 58 degs where doubly rotated orientations are described by the IEEE notation widely known in the art as (YXwl)Phi/Theta and in which the plate is lapped and polished and metallic electrodes then deposited on the major surfaces of the plate, the plate then mounted in an evacuated sealed enclosure to form a transducer and the transducer subjected to an alternating voltage across the electrodes at a frequency that piezoelectrically excites the fundamental harmonic of the thickness shear mode. Keywords: Patent applications. (AW)

Descriptors :   *BORATES, *COUPLING CIRCUITS, *LITHIUM COMPOUNDS, *PATENT APPLICATIONS, *PIEZOELECTRIC EFFECT, *TRANSDUCERS, ALTERNATING CURRENT, AXES, CRYSTALS, ELECTRODES, INVENTIONS, METALS, SHEAR PROPERTIES, TEMPERATURE, TEMPERATURE COEFFICIENTS, THICKNESS, VARIATIONS, VIBRATION, VOLTAGE, SYMMETRY(CRYSTALLOGRAPHY), PLATES, SEALED SYSTEMS, FREQUENCY, SENSITIVITY, EXCITATION

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE