Grating Or Reflector In Wave Path Patents (Class 310/313D)
  • Patent number: 6164135
    Abstract: A method and an apparatus for analyzing a structure, for example, a fingerprint or a hand print, in which the finger or hand is placed upon a plate which forms an ultrasonic wave waveguide and ultrasonic radiation, launched into the waveguide parallel to the surface against which the object is placed. The reflected and backscattered waves are analyzed utilizing horizontally polarized ultrasonic shear waves propagated in the body from at least one transducer at a side of the body. The pickup transducer can also be provided on the side of the body.
    Type: Grant
    Filed: June 5, 1998
    Date of Patent: December 26, 2000
    Assignee: Sonident Anstalt
    Inventor: Wieslaw Bicz
  • Patent number: 6163236
    Abstract: Twin dual mode filter with DMS filters have an input and output transducer (2; 12) per DMS track (A, B) within reflectors (3, 3) and further reflectors (7, 11) between the transducers that are respectively interconnected to one of the transducers. The reflectors (7, 11) of the input or, respectively, output side are respectively connected to one another via interconnects (8, 8). The DMS tracks (A, B) are frequency-shifted relative to one another such that the high-frequency resonance of the low-frequency track (B) falls onto the low-frequency resonance of the high-frequency track (A).
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: December 19, 2000
    Assignee: Siemens Matsushita Components GmbH & Co.
    Inventor: Baier Thomas
  • Patent number: 6160339
    Abstract: To provide a two-port SAW resonator in which spurious responses causes by higher-order vertical inharmonic modes are suppressed, a pair of reflectors and three IDTs are provided on the surface of a piezoelectric plate. The frequency-increase rate of the second and third IDTs is set to be smaller than that of the first IDT so that the frequency-increase rate of the first IDT is 2000 to 12000 ppm. In addition, by setting the number of pairs of the electrodes of the second and third IDTs at 2.75 to 3.75 or a quarter of the number of pairs of the electrodes of all the IDTs, spurious responses caused by higher-order vertical inharmonic modes are suppressed, and equivalent series resistance is reduced to approximately 20.OMEGA.. Therefore, a two-port SAW resonator having a superior frequency stability in a high-frequency band of 500 MHz or higher is realized.
    Type: Grant
    Filed: July 7, 1999
    Date of Patent: December 12, 2000
    Assignee: Seiko Epson Corporation
    Inventors: Michiaki Takagi, Takashi Yamazaki
  • Patent number: 6147574
    Abstract: A unidirectional surface acoustic wave transducer includes a plurality of interdigital transducers and a plurality of reflectors disposed on a piezoelectric substrate. The directivity of a first group of the plurality of reflectors is opposite relative to the directivity of a second group of the plurality of reflectors.
    Type: Grant
    Filed: November 19, 1998
    Date of Patent: November 14, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Hideo Kidoh
  • Patent number: 6140890
    Abstract: A SAW filter, comprising a piezoelectric substrate and a first interdigital electrode having a period of L and disposed on the piezoelectric substrate. The filter converts an input voltage into a surface acoustic wave on the piezoelectric substrate. A second interdigital electrode having the period of L is disposed on the piezoelectric substrate in parallel with the first interdigital electrode with respect to a propagating direction of the surface acoustic wave. The second interdigital electrode converts the surface acoustic wave on the piezoelectric substrate into a voltage. A pair of first reflectors having a period of L/2 are disposed on the piezoelectric substrate and beside both sides of a pair of the first and second interdigital electrodes in the propagating direction keeping a distance of nL/2+0.5 L therefrom, where n is an integer equal to or larger than zero.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: October 31, 2000
    Assignee: NEC Corporation
    Inventor: Natsuhiko Sakairi
  • Patent number: 6137380
    Abstract: A surface acoustic wave filter significantly improves attenuation in the stopband by using a spurious component to improve the filter characteristics. The filter includes a surface acoustic wave substrate and a series resonator having a resonant frequency and an antiresonant frequency. The series resonator is electrically disposed between an input terminal and an output terminal in series so as to define a series arm. The filter also includes at least one parallel resonator having a resonant frequency and an antiresonant frequency which is substantially identical to the resonant frequency of the series resonator. The at least one parallel resonator is electrically disposed between the series arm and a ground terminal so as to define a first parallel arm. The series arm and the parallel arm define a ladder circuit such that the surface acoustic wave filter has a predetermined pass band.
    Type: Grant
    Filed: February 24, 1998
    Date of Patent: October 24, 2000
    Assignee: Murata Manufacturing, Co., Ltd
    Inventors: Tadamasa Ushiroku, Norio Taniguchi
  • Patent number: 6122954
    Abstract: A real time nonvolatile residue (NVR) monitor operates to efficiently detect molecular contamination in a given environment. The present NVR monitor utilizes surface acoustic wave (SAW) resonators in a controlled environment which efficiently promotes deposition of NVR on the sensor surface. The SAW resonators preferably operate at a resonant frequency of approximately 200 MHz-2,000 MHz which enables the NVR monitor to detect molecular contamination on the order of 10.sup.-11 g-cm.sup.-2 to 10.sup.-13 g-cm.sup.-2. The NVR monitor utilizes active temperature control of (SAW) resonators to achieve a stable resonant frequency and to thermally separate NVR from a sample fluid contacting the SAW. The temperature control system of the NVR monitor is able to directly heat and cool the SAW resonators utilizing a thermoelectric element to maintain the resonators at a preset temperature in accordance with optimal environmental conditions for separating NVR from the sample fluid.
    Type: Grant
    Filed: August 21, 1998
    Date of Patent: September 26, 2000
    Assignee: Femtometrics, Inc.
    Inventor: William D. Bowers
  • Patent number: 6121860
    Abstract: The multimode surface acoustic wave filter includes two surface acoustic wave resonators closely arranged on a piezoelectric substrate in a direction perpendicular to the propagation direction of surface acoustic waves and acoustically coupled by a coupling section, each of the surface acoustic wave resonators including an interdigital transducer and two reflectors disposed closely on both sides of the interdigital transducer in a direction parallel to the propagation direction of the surface acoustic waves, the interdigital transducer having an excitation section for exciting the surface acoustic waves and a signal terminal section for inputting an electric signal, each of the reflectors having a grating section and a terminal section, wherein the velocity of surface acoustic waves propagating through the coupling section is a little larger than the velocity of the surface acoustic waves propagating through the excitation section of the interdigital transducer.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: September 19, 2000
    Assignee: Fujitsu Limited
    Inventors: Jun Tsutsumi, Osamu Ikata, Yoshio Satoh
  • Patent number: 6114926
    Abstract: A piezoelectric substrate having two reflectors along a propagation path of a surface acoustic wave and three interdigital electrodes provided on said piezoelectric substrate consecutively between the reflectors. A primary side electrode is connected to an input/output terminal and a secondary side electrode is connected to a second input/output terminal. Each interdigital electrode includes include pairs of electrode fingers, where the pair of electrodes for one interdigital electrode is different than a pair of electrodes for another interdigital electrode.
    Type: Grant
    Filed: July 30, 1999
    Date of Patent: September 5, 2000
    Assignee: Fujitsu Limited
    Inventors: Masanori Ueda, Gou Endoh, Osamu Kawachi, Yoshiro Fujiwara
  • Patent number: 6081172
    Abstract: Surface wave filter for asymmetrical/symmetrical and symmetrical/symmetrical operating mode, with interdigital output transformers (IDT2, IDT4) connected in series.
    Type: Grant
    Filed: February 25, 1999
    Date of Patent: June 27, 2000
    Assignee: Siemens Matsushita Components GmbH & Co. KG
    Inventors: Georg Strauss, Josef Bauregger
  • Patent number: 6075898
    Abstract: A reflective array compressor for a fast pattern recognition system. The system includes a combination of digital and analog processing circuitry which allows the system to achieve super computing processing speeds within an open personal computer architecture. The system receives a bit map which is representative of the unknown pattern, such as a picture of an unknown person. The bit map could have multiple people in it--no other system has "faces in the crowd" ability. The bit map associated with the unknown pattern is then pre-processed and compared against a plurality of known patterns in a database to determine how well the unknown pattern correlates with the known patterns. The reflective array compressor employs concave input and output transducers, and curved reflectors.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: June 13, 2000
    Assignee: FPR Corporation
    Inventor: Walter E. Chase
  • Patent number: 6049260
    Abstract: A surface acoustic wave filter includes IDTs on an input side and on an output side, the Inter Digital Transducers (IDTs) are formed by depositing a thin film made of aluminum and the like on a piezoelectric substrate made of crystal, and disposed on the substrate with a spacing interposed therebetween. The width of each electrode digit of each IDT is 1/4 of the wavelength of the surface acoustic wave during resonance. A reflection coefficient .epsilon. per electrode digit and the total number N of pairs of the electrode digits constituting the IDTs on the input side and on the output side are set to satisfy N.epsilon..gtoreq.0.55. Also, the aperture width W.lambda. of a surface acoustic wave transmission path, the center frequency of the filter f in units of Hertz , and the thickness of the electrode digits H in units of meters, are set to satisfy fH.ltoreq.-17.5W+210.
    Type: Grant
    Filed: January 15, 1999
    Date of Patent: April 11, 2000
    Assignee: NEC Corporation
    Inventors: Susumu Yoshimoto, Yasushi Yamamoto
  • Patent number: 6043726
    Abstract: A surface acoustic wave filter having three acoustic pathways. The first acoustic pathway is made up of a first transducer including a first and second bonding pad and is arranged between two reflectors to form a first resonator. The second acoustic pathway is made of a second transducer including a third and fourth bonding pad and is arranged between two reflectors to form a second resonator. A third acoustic pathway is made of a third transducer including a fifth and sixth bonding pad and is arranged between two reflectors to produce a third resonator. Each bonding pad of the transducers is linked to a specified potential.
    Type: Grant
    Filed: March 25, 1998
    Date of Patent: March 28, 2000
    Assignee: Thomson-CSF
    Inventors: Marc Solal, Jean Desbois
  • Patent number: 6043585
    Abstract: A surface acoustic wave filter provided on a substrate, in which input "hot" and ground busbars and output "hot" and ground busbars are disposed substantially symmetrically with respect to an axis lying between the input and the output of the filter.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: March 28, 2000
    Assignee: Nokia Mobile Phones Limited
    Inventors: Victor Plessky, Serguei Kondratiev
  • Patent number: 6037700
    Abstract: A surface acoustic wave device including, as formed on a piezoelectric substrate, one or a plurality of resonators connected together, each of the resonators comprising an interdigital transducer and a grating reflector, the object of the invention is to compact the device by improving the reflection efficiency of the grating reflector. When the grating reflector is a metal strip array reflector of the open type, the grating reflector has an electrode occupancy ratio of 0.7 to 0.8. Alternatively, when a metal strip array reflector of the short-circuit type is used, the grating reflector has an electrode occupancy ratio of 0.45 to 0.55, or when a metal strip array reflector of the interdigital type is used, the grating reflector has an electrode occupancy ratio of 0.7 to 0.85.
    Type: Grant
    Filed: March 30, 1998
    Date of Patent: March 14, 2000
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Naoki Tanaka, Kazuya Niki, Fumio Kameoka, Masami Ikeda
  • Patent number: 6034578
    Abstract: A surface acoustic wave device which comprises: a plurality of interdigital transducers formed on a surface acoustic wave substrate; and a plurality of thin film electrodes disposed between the interdigital transducers and an end surface of the surface acoustic wave substrate and electrically independently of the interdigital transducers, at least one of distances between adjacent ones of the thin film electrodes being set to be smaller than a distance between the thin film electrodes and the interdigital transducers, so that the electrical performance of the device as well as the insulation resistance does not deteriorate, and the interdigital transducers can be prevented from being electrostatically broken.
    Type: Grant
    Filed: March 11, 1999
    Date of Patent: March 7, 2000
    Assignee: Hitachi Media Electronics Co., Ltd.
    Inventors: Yuji Fujita, Norio Hosaka, Misao Nakajima
  • Patent number: 6025763
    Abstract: In a resonator-type SAW filter, at least one series-arm SAW resonator has an interdigital transducer with reflectors on both sides, and the reflectors are separated from the interdigital transducer by a distance of from (N/2+0.55).lambda..sub.1 to (N/2+0.81).lambda..sub.1, where N is an arbitrary non-negative integer and .lambda..sub.1 is the wavelength of the surface acoustic waves excited by the SAW resonator. Alternatively, from 30% to 80% of the electrode fingers Constituting the interdigital transducer in at least one series-arm SAW resonator are apodized, dividing the interdigital transducer into an excitation region and a dummy region, and the electrode fingers in the dummy region are offset from the electrode fingers in the excitation region by a distance of 0.05.lambda..sub.1 to 0.31.lambda..sub.1.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: February 15, 2000
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Shigeyuki Morimoto
  • Patent number: 6005327
    Abstract: An ultrasonic touch-position sensing device comprises a nonpiezoelectric plate, two ultrasonic transducing units mounted on an upper- or a lower end surface of the nonpiezoelectric plate, and a signal controller connected with the ultrasonic transducing units. Each ultrasonic transducing unit consists of a first- and a second piezoelectric substrates, at least an input interdigital transducer and at least an output interdigital transducer. The output interdigital transducer has at least a finger-overlap zone R.sub.i (i=1). The finger-overlap zone R.sub.i comprises zones R.sub.ia, R.sub.ib and R.sub.im. The finger direction of the zones R.sub.ia and R.sub.ib runs parallel with that of the input interdigital transducer. The finger direction of the zone R.sub.im is slanting to that of the input interdigital transducer. When an electric signal is applied to the input interdigital transducer, an ultrasound is excited in the bilayer zone B.sub.
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: December 21, 1999
    Inventor: Kohji Toda
  • Patent number: 5999068
    Abstract: A surface acoustic wave filter of multi-stage connection type including a plurality of surface acoustic wave filters formed on a piezoelectric substrate and a connection section for electrically connecting the surface acoustic wave filters in a cascade connection. Each of the surface acoustic wave filters includes interdigital transducers with two signal terminals for electric input and output, each interdigital transducer including an excitation section for exciting a surface acoustic wave and two terminal sections disposed on opposite sides of the excitation section, the two terminal sections serving as input or output terminal for electric signal and ground terminal. One of the signal terminal sections is connected to the connection section, and an electrode area of said one of the signal terminal sections is adjusted so that a parasitic capacitance formed between said one of the signal terminal sections and a grounding point of the surface acoustic wave filter is less than or equal to 0.01 pF.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: December 7, 1999
    Assignee: Fujitsu Limited
    Inventors: Jun Tsutsumi, Osamu Ikata, Yoshio Satoh
  • Patent number: 5994817
    Abstract: An ultrasonic touch-position sensing device comprises a piezoelectric substrate, two ultrasonic transducing units formed on an upper end surface of the piezoelectric substrate, and a signal controller connected with the ultrasonic transducing units. Each ultrasonic transducing unit consists of at least an input interdigital transducer and at least an output interdigital transducer. The output interdigital transducer has at least a finger-overlap zone R.sub.i (i=1). The finger-overlap zone R.sub.i comprises zones R.sub.ia, R.sub.ib and R.sub.im. The finger direction of the zones R.sub.ia and R.sub.ib runs parallel with that of the input interdigital transducer. The finger direction of the zone R.sub.im is slanting to that of the input interdigital transducer. When an electric signal is applied to the input interdigital transducer, an ultrasound is excited in the piezoelectric substrate, and transduced to electric signals E.sub.ia and E.sub.ib (i=1, 2, . . . , N) at the zones R.sub.ia and R.sub.
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: November 30, 1999
    Inventor: Kohji Toda
  • Patent number: 5990762
    Abstract: A surface acoustic wave resonator is constituted by an IDT electrode and reflector electrodes disposed on both sides thereof, on a piezoelectric substrate. Two of said surface acoustic wave resonators are disposed nearby so that the propagation directions of the respective surface acoustic waves are in parallel to each other to make acoustic couple to constitute a surface acoustic wave filter having plural exciting modes with different propagation frequencies. The bus bar electrodes of each of two IDT electrodes are electrically separated from each other, and the leading out electrodes led out from at least two spots on those bus bar electrodes are electrically connected to each other, by which one side of the balanced input and output terminal. As a result, the electrode resistance of the IDT electrode is alleviated to make the insertion loss less.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: November 23, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroyuki Nakamura, Toru Yamada, Kazunori Nishimura, Toshio Ishizaki
  • Patent number: 5986524
    Abstract: A three-electrode longitudinally-coupled-type SAW resonator filter has an improved level of selectivity by effectively suppressing unwanted large spurious responses generated in a range higher than the pass band. A first ID electrode, a second ID electrode and a third ID electrode are disposed on a piezoelectric substrate. Reflectors are provided on one side of each of the second and third ID electrodes, respectively. A center distance L.sub.1 between the most adjacent electrode fingers of the respective first and second ID electrodes is differentiated from the center distance L.sub.2 between the most adjacent electrode fingers of the respective first and third ID electrodes. Further, the first ID electrode is weighted to more effectively suppress undesired spurious responses.
    Type: Grant
    Filed: November 24, 1997
    Date of Patent: November 16, 1999
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Kazunobu Shimoe
  • Patent number: 5986382
    Abstract: An acoustic wave identification transponder device, having a substrate, an electroacoustic transducer generating an acoustic wave in said substrate and a set of encoding elements disposed in a path of the acoustic wave for modifying the acoustic wave, having at least two reflective elements disposed in the acoustic path of the acoustic wave such that an acoustic path length of the acoustic wave on the substrate is longer than twice a largest linear dimension of the substrate. The device preferably includes an angled elongated conductor formed on said substrate, having angle magnitudes whose sum exceeds .pi. radians, said angled elongated conductor defining at least a portion of the acoustic path.
    Type: Grant
    Filed: August 18, 1997
    Date of Patent: November 16, 1999
    Assignee: X-Cyte, Inc.
    Inventor: Paul A. Nysen
  • Patent number: 5966061
    Abstract: A surface acoustic wave filter has an input electrode and an output electrode of a finger type with mutually parallel elongated fingers formed generally at a constant pitch on a piezoelectric substrate and sandwiched between a pair of reflectors. Two of these fingers of the input electrode which are the closest and the second closest to the output electrode, or two of these fingers of the output electrode which are the closest and the second closest to the input electrode, are connected together to a same grounding terminal. A plurality of such filters may be connected together to form a multi-stage filter.
    Type: Grant
    Filed: November 7, 1996
    Date of Patent: October 12, 1999
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Yutaka Tada
  • Patent number: 5966060
    Abstract: A surface acoustic wave apparatus includes first and second longitudinally-coupled resonator filters disposed on a surface-wave board. In each longitudinally-coupled resonator filter, the ground electrodes of IDTs disposed at opposite sides of the center IDT and adjacent to reflectors are connected to different ground electrodes located on the same layer in the package, with at least two bonding wires.
    Type: Grant
    Filed: September 16, 1997
    Date of Patent: October 12, 1999
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Katsuhiro Ikada
  • Patent number: 5962950
    Abstract: In a surface acoustic wave apparatus, a surface acoustic wave element for obtaining a convolution signal is housed in a recess of a substrate. Since the surface acoustic wave element is housed in the recess of the substrate in this surface acoustic wave apparatus, the apparatus can be compactified. This effect of compactification is remarkable, because the surface acoustic wave element has an output electrode for obtaining the convolution signal and thus originally has a big element size. When a laminate substrate is used as the substrate, a configuration for effectively using surfaces of respective layers may be arranged in such a manner that output wiring of the convolution signal is separately formed in the layers. This further enhances the effect of compactification. There are further disclosed a spread spectrum signal receiver using the above surface acoustic wave apparatus for receiving a spread spectrum signal, and a spread spectrum communication system using the spread spectrum signal receiver.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: October 5, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koichi Egara, Akira Torisawa, Tadashi Eguchi, Akihiro Koyama, Takahiro Hachisu, Akane Yokota
  • Patent number: 5963114
    Abstract: A surface-acoustic-wave device includes at least first and second surface-acoustic-wave elements formed on a common piezoelectric substrate and cascaded with each other, each of the first and second surface-acoustic-wave elements including a plurality of interdigital electrodes having a plurality of electrode fingers overlapping with each other in correspondence to a path of a surface acoustic wave on the piezoelectric substrate, wherein the width of overlapping of the electrode fingers is changed between the first surface-acoustic-wave element and the second surface-acoustic-wave element.
    Type: Grant
    Filed: December 3, 1996
    Date of Patent: October 5, 1999
    Assignee: Fujitsu Limited
    Inventors: Masanori Ueda, Gou Endoh, Osamu Kawachi, Yoshiro Fujiwara
  • Patent number: 5955933
    Abstract: In a surface acoustic wave filter constituted with a ladder of resonators having a resonance frequency or an anti-resonance frequency, an input current flowing into a resonator in a parallel arm at the first stage from the input is so large as to deteriorate its lifetime caused from a heat generation by the resistance of the thin film wiring. As a measure to this problem, bonding wires (30, 31) connected onto points on connection electrodes (130, 131) for connecting an end of each of plural comb teeth electrodes 111 forming the resonators R.sub.s1 & R.sub.p1, or on a lead conductor (130-1) extended longitudinally from the connection electrode, are allotted at both sides of a center line (C1) of the plural comb teeth electrode group. Furthermore, a bonding wire may be connected substantially onto the center line C1 as well. It is preferable for the bonding wires to be located substantially symmetric with respect to the center line C1.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: September 21, 1999
    Assignee: Fujitsu Limited
    Inventors: Tokihiro Nishihara, Yoshio Satoh, Hidema Uchishiba, Takashi Matsuda, Osamu Ikata
  • Patent number: 5949307
    Abstract: A surface acoustic wave device includes first and second longitudinal mode resonators. The first longitudinal mode resonator has two resonance modes, i.e., a longitudinal mode distributed in the same direction as a propagating direction of a surface acoustic wave (SAW) and a transverse mode distributed in a direction perpendicular to the propagating direction of the SAW. The second longitudinal mode resonator is arranged adjacent to the first resonator in a direction perpendicular to the propagating direction of the SAW, and has two resonance modes, i.e., a longitudinal mode and a transverse mode. The resonance modes of the second longitudinal mode resonator are acoustically coupled to the resonance modes of the first longitudinal mode resonator. The first longitudinal mode resonator has an output InterDigital Transducer (IDT) having an interdigital electrode to excite a SAW. The second longitudinal mode resonator has an input IDT having an interdigital electrode to receive the SAW from the output IDT.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: September 7, 1999
    Assignee: NEC Corporation
    Inventors: Susumu Yoshimoto, Yasushi Yamamoto
  • Patent number: 5945893
    Abstract: A surface acoustic wave filter provided on a substrate, comprising a transducer and a first reflector for surface acoustic waves at one end of the transducer, the first reflector being integral with conductive material that defines a busbar of the filter.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: August 31, 1999
    Assignee: Nokia Moile Phones Limited
    Inventors: Victor Plessky, Serguei Kondratiev
  • Patent number: 5936488
    Abstract: A surface acoustic wave filter is provided which performs balanced signal/unbalanced signal conversion. The input and output impedances are different from each other. In a surface acoustic wave filter of the longitudinal mode type, a signal is applied to two terminals of an input interdigital transducer, or a signal is output from two terminals of an output interdigital transducer, thereby consituting a balanced type filter. The aperture length of the input interdigital transducer is different from that of the output interdigital transducer.
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: August 10, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yutaka Taguchi, Kazuo Eda, Shunichi Seki, Keiji Onishi
  • Patent number: 5936487
    Abstract: The disclosure relates to differential input/output surface acoustic wave devices with proximity coupling. The disclosed device comprises a whole number N of acoustic channels, where N is at least equal to two. The acoustic channels are coupled together by proximity. A first acoustic channel comprises at least one transducer separated into several parts electrically connected in parallel with one another to form a first differential port (E+) and a second differential port (E-). The polarities of the different parts of the transducer are chosen so that the first differential port (E+) and the second differential port (E-) are electrically symmetrical. Application in particular to surface acoustic wave filters for portable telephones.
    Type: Grant
    Filed: April 9, 1998
    Date of Patent: August 10, 1999
    Assignee: Thomson-CSF
    Inventors: Marc Solal, Pierre Dufilie
  • Patent number: 5932950
    Abstract: A SAW resonator disposed with an IDT electrode and reflector electrodes is formed on the surface of a piezoelectric substrate. Three pieces of the SAW resonator form an acoustic coupling by being disposed close to each other, electrode fingers comprising the IDT electrode in the center are all grounded, and IDT electrode fingers are electrically independent on the side to be connected to input-output terminals of the IDT electrodes disposed outside. As a result, three excitation modes having different propagation frequencies are generated which are used to attain a broad band SAW resonator filter. When these three pairs of the IDT electrode are electrically independent, a balanced input-output can be achieved, and excellent out-of-band rejection characteristics can be obtained.
    Type: Grant
    Filed: August 6, 1996
    Date of Patent: August 3, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toru Yamada, Toshio Ishizaki, Kazunori Nishimura, Kozo Murakami
  • Patent number: 5918258
    Abstract: A real time nonvolatile residue (NVR) monitor operates to efficiently detect molecular contamination in a given environment. The present NVR monitor utilizes surface acoustic wave (SAW) resonators in a controlled environment which efficiently promotes deposition of NVR on the sensor surface. The SAW resonators preferably operate at a resonant frequency of approximately 200 MHz-2,000 MHz which enables the NVR monitor to detect molecular contamination on the order of 10.sup.-11 g-cm.sup.-2 to 10.sup.-13 g-cm.sup.-2. The NVR monitor utilizes active temperature control of (SAW) resonators to achieve a stable resonant frequency and to thermally separate NVR from a sample fluid contacting the SAW. The temperature control system of the NVR monitor is able to directly heat and cool the SAW resonators utilizing a thermoelectric element to maintain the resonators at a preset temperature in accordance with optimal environmental conditions for separating NVR from the sample fluid.
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: June 29, 1999
    Inventor: William D. Bowers
  • Patent number: 5914646
    Abstract: A surface acoustic wave filter element is formed by replacing with a single parallel resonator having a driving electrode whose area is equal to the sum total of the areas of driving electrodes of a plurality of consecutive parallel resonators arranged in a ladder shape, together with serial resonators, for structuring a surface acoustic wave resonator. Also, in a surface acoustic wave filter formed by packaging the surface acoustic wave filter element, ground electrodes of the parallel resonators of the filter element are electrically insulated from each other and are connected to different electrode pads for grounding.
    Type: Grant
    Filed: April 3, 1997
    Date of Patent: June 22, 1999
    Assignee: Fujitsu Limited
    Inventor: Kazushi Hashimoto
  • Patent number: 5912602
    Abstract: A high-precision surface acoustic wave (SAW) device improves the frequency-temperature characteristics of a conventional surface acoustic wave device several-fold. In this high-precision surface acoustic wave device, two one-port SAW resonators, or two two-port SAW resonators, alternatively, two one-port-resonator-type, two-port-resonator-type or transversal-type filters are placed in parallel with each other. Further, these resonators or filters are excited and are elastically coupled to each other in such a way as to be in an oblique symmetry mode. Moreover, the frequency-temperature characteristics of the two elements are made to differ from each other. Furthermore, a flat frequency-temperature characteristic, which cannot be realized by a single element, is realized by being synthesized from the frequency-temperature characteristics of the two elements.
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: June 15, 1999
    Assignee: Seiko Epson Corporation
    Inventors: Michiaki Takagi, Shigeo Kanna, Eishi Momosaki
  • Patent number: 5909158
    Abstract: A surface acoustic wave resonator filter has a wide bandwidth, a low insertion loss characteristic and a sharp attenuation characteristic at edges of the passband. The surface acoustic wave resonator filter includes first and second longitudinally coupled resonator filters disposed on a piezoelectric substrate. The first and second longitudinally coupled resonator filters each have first, second, and third resonance modes. The phases of the output signals of the first and second longitudinally coupled resonator filters are opposite to each other for an input signal at frequencies higher than the passband. The difference in frequency between the first resonance mode of the first longitudinally coupled resonator filter and the first resonance mode of the second longitudinally coupled resonator filter is smaller than the difference in frequency between the first resonance mode and any other resonance modes in the first and second longitudinally coupled resonator filters.
    Type: Grant
    Filed: August 27, 1997
    Date of Patent: June 1, 1999
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Masahiro Hiramoto
  • Patent number: 5896071
    Abstract: A surface wave device comprises first and second SPUDT (single phase unidirectional transducer) resonator filters each comprising first and second transducers, which are preferably RSPUDTs (resonant SPUDTs), the resonator filters being the same except that one transducer of the second resonator filter is a mirror image of the corresponding transducer of the first resonator filter to provide a phase difference of 180.degree.. The surface wave device serves as a balun by having an unbalanced signal connection to the first transducers, and a balanced signal connection comprising signal connections to the second transducer of each of the first and second resonator filters. The resonator filters can be arranged side by side on a common piezoelectric substrate.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: April 20, 1999
    Assignee: Northern Telecom Limited
    Inventors: Ji-Dong Dai, Yufeng Xu, Thomas Philip Cameron
  • Patent number: 5896072
    Abstract: A surface acoustic wave filter has one or more acoustic filter tracks. Each track has an input interdigital converter, an output interdigital converter, and a reflector. The reflector reflects surface waves between the input and output inter-digital converter by 180.degree.. The reflector is formed with a multiplicity of reflector electrode fingers which are combined into reflector finger groups. Mutually adjacent reflector finger groups are spaced apart by a defined spacing distance such that respective signals in adjacent reflector finger groups are superimposed in antiphase.
    Type: Grant
    Filed: December 23, 1996
    Date of Patent: April 20, 1999
    Assignee: Siemens Matsushita Components GmbH & Co. KG
    Inventors: Andreas Bergmann, Jurgen Machui
  • Patent number: 5886452
    Abstract: An SH wave position-sensing device comprising two SH wave transducing units X and Y, a nonpiezoelectric plate and a signal controller. Each unit contains piezoelectric substrates P.sub.T0, P.sub.R0, P.sub.Ti (i=1, 2, . . . , N) and P.sub.Ri (i=1, 2, . . . , N), interdigital transducers T.sub.0, R.sub.0, T.sub.i (i=1, 2, . . . , N) and R.sub.i (i=1, 2, . . . , N). The interdigital transducers T.sub.0, R.sub.0, T.sub.i and R.sub.i, are formed on an upper- or a lower end surface of the piezoelectric substrates P.sub.T0, P.sub.R0, P.sub.Ti and P.sub.Ri, respectively. The lower end surface of each piezoelectric substrate is cemented on an upper end surface of the nonpiezoelectric plate. The finger direction of each interdigital transducer R.sub.i is slanting to that of each interdigital transducer T.sub.i. When an electric signal is applied to the interdigital transducer T.sub.0, an SH wave is excited in a bilayer zone B.sub.T0 formed by the piezoelectric substrate P.sub.
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: March 23, 1999
    Inventor: Kohji Toda
  • Patent number: 5883457
    Abstract: A touch sensor system, including a substrate, capable of propagating surface acoustic waves; and a reflective array formed on said substrate, said reflective array having a plurality of reflective elements, each reflective element reflecting a portion of an incident surface acoustic wave. The reflective array is formed of an organic matrix. The organic matrix is preferably chemically bonded to the substrate, and is preferably a thermoset resin. The resulting reflective arrays are preferably stable under changes in moisture between 0% and 60% RH at temperatures between about 0.degree.-50.degree. C. The organic matrix can also be used in a humidity or chemical sensor.
    Type: Grant
    Filed: April 24, 1997
    Date of Patent: March 16, 1999
    Assignee: Raychem Corporation
    Inventors: James A. Rinde, Barry C. Mathews
  • Patent number: 5877661
    Abstract: A surface acoustic wave filter comprises a first electrode structure array which is formed on the piezoelectric substrate, and includes an input/output IDT, two receipt IDTs formed outside the input/output IDT and two reflectors formed outside the two receipt IDTs, and a second electrode structure array which is formed on the piezoelectric substrate and includes an input/output IDT, two receipt IDTs formed outside the input/output IDT and two reflectors formed outside the two receipt IDTs, which are concatenated with each other. In a case that the surface acoustic wave filter is represented by a symmetrical lattice-type circuit which is expressed by a serial arm impedance and a parallel arm impedance and is electrically equivalent to the same, at least two resonances of the serial arm impedance and at least three resonances of the parallel arm impedance are used to form a passband. The surface acoustic wave filter can have wide bands and low spurious signal.
    Type: Grant
    Filed: June 17, 1997
    Date of Patent: March 2, 1999
    Assignee: Kinseki, Limited
    Inventors: Masashi Ohmura, Hiroshi Honmo, Hidenori Abe
  • Patent number: 5877662
    Abstract: A surface acoustic wave filter according to the present invention is constructed by connecting in series one or two or more filter functional units each comprising a first surface acoustic wave resonator having input and output terminals connected in series with a signal line and a second surface acoustic wave resonator having input and output terminals one of which is connected to the signal line and the other of which is grounded. The first surface acoustic wave resonator is constituted by one interdigital transducer and a pair of electrically open strip type grating reflectors with the interdigital transducer interposed therebetween, and the second surface acoustic wave resonator is constituted by one interdigital transducer and a pair of electrically short strip type grating reflectors with the interdigital transducer interposed therebetween.
    Type: Grant
    Filed: April 19, 1996
    Date of Patent: March 2, 1999
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasumi Kobayashi, Kuniyuki Matsui, Yasuhiro Hirao, Kousuke Takeuchi, Hiroshi Kayaki, Yusuke Takahashi, Toshiharu Tanaka, Isao Kiyose, Kenichi Shibata
  • Patent number: 5874869
    Abstract: A surface acoustic wave device includes a piezoelectric substrate of a LiTaO.sub.3 single crystal, the crystal having X, Y and Z axes and a cut plane. The X axis of the crystal is oriented in a direction of propagation of surface acoustic waves. The cut plane of the crystal is rotated around the X axis at a rotated angle from the Y axis to the Z axis, the rotated angle being in a range between 40.degree. and 42.degree.. A pair of reflectors are formed on the substrate and aligned in a row in the direction of propagation. Interdigital transducers are formed on the substrate and aligned in the row in the direction of propagation, the interdigital transducers interposed between the reflectors, each interdigital transducer having pairs of mutually opposed primary electrode fingers and secondary electrode fingers, the interdigital transducers including at least a front transducer, a middle transducer and a rear transducer aligned in the row in the direction of propagation.
    Type: Grant
    Filed: September 9, 1997
    Date of Patent: February 23, 1999
    Assignee: Fujitsu Limited
    Inventors: Masanori Ueda, Osamu Kawachi, Gou Endoh, Yoshiro Fujiwara
  • Patent number: 5874868
    Abstract: A longitudinal coupling type SAW resonator filter achieves improved selectivity without increasing the insertion loss and is constructed so as to be more easily mass-produced. The longitudinal coupling type SAW resonator filter has a piezoelectric substrate and first, second and third sets of interdigital electrodes each including a pair of comb electrodes disposed on the piezoelectric substrate. A pair of reflectors are located on the opposite sides in the surface wave propagation direction of the area in which the first to third sets of interdigital electrodes are disposed. The distance between the centers of adjacent electrode fingers of the first and second sets of interdigital electrode and the distance between the centers of adjacent electrode fingers of the first and third sets of interdigital electrode are set to different values.
    Type: Grant
    Filed: December 27, 1996
    Date of Patent: February 23, 1999
    Assignee: Murata Manufacturing, Co., Ltd.
    Inventor: Kazunobu Shimoe
  • Patent number: 5867074
    Abstract: A surface acoustic wave resonator unit using surface acoustic wave, in which a surface acoustic wave resonator formed by disposing an IDT and reflectors on a piezoelectric member thereof is mounted by a cantilever method so that a surface acoustic wave resonator unit exhibiting very stable resonance frequency, a low resonance resistance and a large Q-value is realized. By accommodating the surface acoustic wave resonator in a housing in a vacuum state, the Q-value can be enlarged. By anodic-oxidizing the electrodes forming the IDT, a thick oxide film can be formed, the oxide film enabling the electrodes to be protected from problems, such as short circuit taking due to foreign matters, such as dust, with the characteristics maintained. If the high performance surface acoustic wave resonator unit is molded together with a lead frame by resin, a surface acoustic wave device, that can be mounted on the surface, and that exhibits excellent reliability and high quality, can be provided.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: February 2, 1999
    Assignee: Seiko Epson Corporation
    Inventors: Hiroyuki Ogiso, Shuuichi Iguchi, Fumitaka Kitamura
  • Patent number: 5856720
    Abstract: In a resonator type surface acoustic wave filter, a fundamental mode of a mode to distribute in a direction perpendicular to propagating direction of a surface acoustic wave (hereinafter referred to as transverse mode) becomes a primary response, whereas a transverse secondary mode becomes spurious. In case of the surface acoustic wave device formed on a piezoelectric substrate having smaller electromechanical coupling factor of a quartz substrate or so forth, it is impossible to obtain sufficient restriction of the second mode spurious. This problem is solved by canceling electrical potential of transverse secondary mode and whereby restricting excitation with a resonator type surface acoustic device formed on a quartz substrate, in which a configuration of an interdigital electrode is selected to establish a ratio of an overlap width of an electrode finger versus an aperture width in a range greater than or equal to 0.75 to smaller than or equal to 0.85.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: January 5, 1999
    Assignee: NEC Corporation
    Inventors: Susumu Yoshimoto, Yasushi Yamamoto
  • Patent number: 5850167
    Abstract: A first electrode structure row formed on a piezoelectric substrate, and including N1 pairs of an input/output IDT, N2 pairs of a connection IDT, and reflectors is cascade-connected to a second electrode structure row formed on the piezoelectric substrate, and including N1 pairs of an input/output IDT, N2 pairs of a connection IDT, and reflectors, the connection IDT of the first electrode structure row, and the connection IDT of the second electrode structure row being arranged electrically symmetric with respect to the cascade-connected plane. The pair number N1 of the input/output IDT is different from the pair number N2 of the connection IDT. When a normalized electrode film thickness of the input/output IDT and the connection IDT is represented by h/L, the pair number N1 of the input/output IDT satisfies the following formula43-11(h/L).ltoreq.N1.ltoreq.61-11(h/L).
    Type: Grant
    Filed: March 20, 1997
    Date of Patent: December 15, 1998
    Assignee: Kinseki, Limited
    Inventor: Hidenori Abe
  • Patent number: 5841214
    Abstract: An identification mark operating with acoustical surface waves includes at least one reflector having higher reflectivity than a reflectivity of other reflectors.
    Type: Grant
    Filed: August 22, 1996
    Date of Patent: November 24, 1998
    Assignee: Siemens Aktiengesellschaft
    Inventors: Frank Schmidt, Valentin Magori, Leonhard Reindl, Thomas Ostertag
  • Patent number: 5838088
    Abstract: A surface acoustic wave position-sensing device comprising two surface acoustic wave transducing units, a nonpiezoelectric plate and a controlling system connected with the units. Each unit consists of two piezoelectric substrates, a first group of interdigital transducers (IDTs) and a second group of interdigital transducers (IDTs). The second group of the IDTs is placed such that the finger direction thereof is slanting to that of the first group of the IDTs by an angle .alpha.. The thickness of each piezoelectric substrate is smaller than an interdigital periodicity of the IDTs. The thickness of the nonpiezoelectric plate is larger than three times the interdigital periodicity. When an electric signal is applied to the first group of the IDTs, a SAW is excited in one of the piezoelectric substrates and transmitted to the other of the piezoelectric substrates through the upper end surface of the nonpiezoelectric plate.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: November 17, 1998
    Inventor: Kohji Toda