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Patent

Temperature stabilization of surface acoustic wave substrates

02 Jul 1974-
TL;DR: In this article, a surface acoustic wave (SAW) structure is disclosed wherein a SAW device is incorporated as an exterior lamina within a composite laminate in order to temperature stabilize the acoustic device.
Abstract: A surface acoustic wave (SAW) structure is disclosed wherein a SAW device is incorporated as an exterior lamina within a composite laminate in order to temperature stabilize the acoustic device. The composite laminate is synthesized to selectively mismatch the thermal expansion characteristics of the piezoelectric material, which is the body of the acoustic device, along the axis of acoustic propagation and simultaneously approximately match the thermal expansion properties along the orthogonal axis. Compressive force is thereby applied to the acoustic device to keep the substrate length constant and thus provide an approximately zero temperature coefficient over a preferred range of temperatures.
Citations
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Patent
05 Sep 2012
TL;DR: In this article, the authors define a duplexer as a single-input-multiple-output (SIMO)-duplication (D2DM) system with at least two IDTs (Interdigital Transducers).
Abstract: A duplexer includes: a transmit filter that is connected between an antenna terminal and a transmit terminal and has a plurality of acoustic wave resonators; a receive filter that is connected between the antenna terminal and a receive terminal and has a plurality of acoustic wave resonators; and a delay line or a longitudinal coupling type resonator that is connected in parallel with at least one of the plurality of acoustic wave resonators of the transmit filter and the plurality of acoustic wave resonators of the receive filter and has at least two IDTs (Interdigital Transducers).

56 citations

Patent
29 May 1998
TL;DR: In this article, a surface acoustic wave device has a main substrate, a comb-like electrode formed on one of the main surfaces of said main substrate; and a supplementary substrate joined with the other main surface of the substrate, wherein said supplementary substrate has a smaller thermal expansion coefficient and a larger thickness than the main substrate.
Abstract: A surface acoustic wave device has a main substrate; a comb-like electrode formed on one of the main surfaces of said main substrate; and a supplementary substrate joined with the other main surface of said main substrate, wherein said supplementary substrate has a smaller thermal expansion coefficient and a larger thickness than said main substrate.

49 citations

Patent
16 Mar 1976
TL;DR: In this paper, a multi-layered substrate for a surface-acoustic-wave device which substrate comprises a piezoelectric layer on a base, the temperature coefficient of a phase velocity of the SAW in the layer being different from that of the base, was presented.
Abstract: This invention provides a multi-layered substrate for a surface-acoustic-wave device which substrate comprises a piezoelectric layer on a base, the temperature coefficient of a phase velocity of the surface-acoustic-wave in the piezoelectric layer being different from that of the base, the piezoelectric layer having a thickness less than a wavelength of the SAW. This multi-layered substrate can have a large electromechanical coupling and controlled temperature coefficient of the phase velocity.

38 citations

Patent
06 Jun 2000
TL;DR: In this paper, a surface acoustic wave element includes a laminated substrate where a first substrate made of a piezoelectric material is laminated over a second substrate made from a material different from that of the first substrate, and at least one pair of comb-shaped electrodes formed on one main plane of the substrate.
Abstract: A surface acoustic wave element includes a laminated substrate where a first substrate made of a piezoelectric material is laminated over a second substrate made of a material different from that of the first substrate, and at least one pair of comb-shaped electrodes formed on one main plane of the first substrate. A step or a notch is formed on the periphery of the laminated substrate on the side of the first substrate.

34 citations

Patent
03 Nov 1999
TL;DR: In this paper, a surface acoustic wave device includes a piezoelectric substrate, and an interdigital transducer provided on the substrate, where at least two ceramic layers made of a polycrystalline material are stacked so that electrical characteristics and mechanical characteristics vary in a direction that is substantially perpendicular to a surface of the substrate.
Abstract: A surface acoustic wave device includes a piezoelectric substrate, and an interdigital transducer provided on the piezoelectric substrate, wherein the piezoelectric substrate includes at least two piezoelectric ceramic layers made of a polycrystalline material. The at least two piezoelectric ceramic layers are stacked so that electrical characteristics and mechanical characteristics thereof vary in a direction that is substantially perpendicular a surface of the piezoelectric substrate upon which the at least two ceramic piezoelectric layers are stacked.

26 citations

References
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Patent
27 May 1965
TL;DR: In this article, a piezoelectric transducer is used for measuring fluid pressure up to and above ballistics levels of the order of 75,000 pounds per square inch with an accurate linear response over a wide pressure range.
Abstract: A piezoelectric pressure transducer particularly adapted for measuring fluid pressure up to and above ballistics levels of the order of 75,000 pounds per square inch with an accurate, linear response over a wide pressure range. The piezoelectric sensing element is housed in a cylindrical sleeve which is threaded into a wall of the chamber within which the pressure to be measured is developed. An end wall extending across the end of the sleeve is exposed to the pressure and deflects, compressing the piezoelectric element to generate an electric signal representing the pressure. A supporting wall for the end wall is located between the sensing element and the housing sleeve. Two flexure zones are formed in the end wall, one between the piezoelectric element and the supporting wall and the other between the wall and the sleeve. The supporting wall is connected with the end wall through a third flexure zone. The compliance of the supporting wall is less than the compliance of the piezoelectric element but greater than the compliance of the housing sleeve. Deformation of the housing sleeve, as by pressure on the mounting threads, is accommodated by the flexure areas and error creating stress on the piezoelectric element is minimized.

52 citations

Patent
01 Oct 1971
TL;DR: In this paper, a temperature compensated acoustic surface wave delay line is provided by the deposition of an interdigital electrode structure on a substrate with an overlay film surface of piezoelectric material of a predetermined thickness.
Abstract: A temperature compensated acoustic surface wave device, such as a surface wave delay line is provided in which temperature compensation is provided by the deposition of an interdigital electrode structure on a substrate with an overlay film surface of piezoelectric material of a predetermined thickness. A double substrate arrangement is also disclosed in which the interdigital electrode structure is deposited upon the surface of a non-piezoelectric layer which in turn is placed upon the surface of a piezoelectric substrate.

43 citations

Patent
04 Dec 1967
TL;DR: An acceleration measuring device which includes within a casing a piezo-electric system, a seismic mass and a relatively fixed abutment is described in this article, where temperature-compensating elements are provided at the outer end or ends of the piezoelectric system which have a coefficient of expansion greater than that of the materials of the adjacent elements.
Abstract: An acceleration measuring device which includes within a casing a piezo-electric system, a seismic mass and a relatively fixed abutment; temperature-compensating elements are provided at the outer end or ends of the piezo-electric system which have a coefficient of expansion greater than that of the materials of the adjacent elements.

19 citations

Patent
21 Nov 1966

18 citations