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Patent

Temperature compensated acoustic surface wave device

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.
Citations
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Patent
18 Jan 1990
TL;DR: In this paper, an ultrasonic sensor which has a thin planar sheet of material forming a Lamb wave propagation medium, the sheet having a thickness which is no greater than about twenty microns, was used to measure selected characteristics of the output electrical signal.
Abstract: An ultrasonic sensor which has a thin planar sheet of material forming a Lamb wave propagation medium, the sheet having a thickness which is no greater than about twenty microns The sensor also includes a Lamb wave generator for generating Lamb waves in the propagation medium and an output device for producing an electrical signal representative of the propagation characteristics of the Lamb waves propagating along the propagation medium A measuring device is included in the sensor to measure selected characteristics of the output electrical signal The propagation medium has some physical characteristics that are determined by the value of a measurand acting on the medium and the determined physical characteristics determine the propagation characteristics of the Lamb waves which are propagated along the medium When the sensor is acted on by a measurand to determine the physical characteristics of the propagation medium, the characteristics of the electrical signal are also determined The measuring device measures the electrical signal and provides an indication of the measurand value Several sensing arrangements are also disclosed as well as methods for making the planar propagation medium

131 citations

Patent
10 Oct 1991
TL;DR: In this paper, an ultrasonic structure which has a thin planar sheet of material forming a Lamb wave propagation medium is described, and a measuring device can be included to measure selected characteristics of the output electrical signal.
Abstract: An ultrasonic structure which has a thin planar sheet of material forming a Lamb wave propagation medium The propagation medium is coated with a gel. The structure may also include a Lamb wave generator for generating Lamb waves in the propagation medium and an output device for producing an electrical signal representative of the propagation characteristics of the Lamb waves propagating along the propagation medium. A measuring device can be included to measure selected characteristics of the output electrical signal. The propagation medium has some physical characteristics that are determined by the value of a measurand acting on the medium and the determined physical characteristics determine the propagation characteristics of the Lamb waves which are propagated along the medium. When the sensor is acted on by a measurand to determine the physical characteristics of the propagation medium, the characteristics of the electrical signal are also determined. The measuring device measures the electrical signal and provides an indication of the measurand value.

110 citations

Patent
08 May 2014
TL;DR: In this paper, techniques, systems, and devices for implementing for implementing computation devices and artificial neurons based on nanoelectromechanical (NEMS) systems are described, where a substrate and two electrodes configured as a first beam structure and a second beam structure positioned in close proximity with each other without contact are described.
Abstract: Techniques, systems, and devices are described for implementing for implementing computation devices and artificial neurons based on nanoelectromechanical (NEMS) systems. In one aspect, a nanoelectromechanical system (NEMS) based computing element includes: a substrate; two electrodes configured as a first beam structure and a second beam structure positioned in close proximity with each other without contact, wherein the first beam structure is fixed to the substrate and the second beam structure is attached to the substrate while being free to bend under electrostatic force. The first beam structure is kept at a constant voltage while the other voltage varies based on an input signal applied to the NEMS based computing element.

56 citations

Patent
03 Jan 1975
TL;DR: In this paper, a temperature compensated surface acoustic wave device with an SiO 2 film layer upon a substrate of piezoelectric material is presented, where the positive temperature coefficient of delay of the substrate is counterbalanced by the negative temperature coefficients of the SiO2 layer.
Abstract: A temperature compensated surface acoustic wave device having an SiO 2 film layer upon a substrate of piezoelectric material. The positive temperature coefficient of delay of the piezoelectric substrate is counterbalanced by the negative temperature coefficient of the SiO 2 layer. The thickness and shape of the SiO 2 layer are chosen to give a zero first order temperature coefficient for the composite device. Lithium niobate and lithium tantalate are preferred piezoelectric materials for the substrate. A high degree of temperature stability is thereby obtained with coupling coefficients much greater than were previously obtained by prior temperature compensated surface acoustic wave devices.

45 citations

Patent
Kazuo Eda1, Yutaka Taguchi1
04 Oct 1994
TL;DR: In this article, a surface acoustic wave-semiconductor composite device is proposed, in which a piezoelectric plate and a semiconductor plate are layered directly or with a gap between them.
Abstract: In a surface acoustic wave-semiconductor composite device such as a surface acoustic wave convolver, a piezoelectric plate and a semiconductor plate are layered directly or with a gap between them. Input electrodes are provided to apply a plurality of input signals to the piezoelectric plate to excite surface acoustic waves, while an output electrode is provided to detect a convolution output signal of a change in electric potential of the semiconductor plate at an interface of the semiconductor plate with the piezoelectric plate. In the layered structure, the semiconductor plate is bonded directly to the piezoelectric plate by hydrogen bonds between hydroxyl groups or by covalent or ionic bonds of oxygen atoms with component atoms of the piezoelectric and semiconductor plates. In modified structures, an inorganic thin film is applied to one of the piezoelectric and semiconductor plates, while the inorganic thin film is bonded directly to the other of the two plates. The surface acoustic wave-semiconductor composite device can be prepared by using direct bonding in an atomic order, with a thickness of a direct bonding layer of 20 nm or less. Then, it has a low insersion loss and a high efficiency, and it is stable thermally and mechanically. Further, its characteristics can be reproduced well.

45 citations

References
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Patent
04 Feb 1971
TL;DR: In this paper, a distributed transducer surface wave device, comprising a crystal substrate, capable of propagating a surface wave, and a pair of transducers disposed in an aligned relationship upon the crystal substrate including an input and output transducers, is presented.
Abstract: A distributed-transducer surface wave device, comprising a crystal substrate, capable of propagating a surface wave, and a pair of transducers disposed in an aligned relationship upon the crystal substrate, including an input and output transducer, each of which includes at least one pair of interdigitated electrodes disposed perpendicularly to the direction of surface wave propagation caused by the application of an input signal to the input transducer. The distance between each pair of adjacent electrodes for each of the transducers is uniform. A feedback loop is connected from the output of the output transducer to the input of the input transducer.

23 citations

Patent
21 Nov 1966

18 citations

Journal ArticleDOI
TL;DR: The use of elastic surface wave devices in modern radar and communications signal processing has been discussed in this article, where it is shown that the fabrication techniques involved are compatible with integrated microcircuit techniques so widespread in general microwave technology.

17 citations