Patents by Inventor Joji Fujiwara

Joji Fujiwara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10979028
    Abstract: An electronic filter includes a plurality of series arm acoustic wave resonators electrically connected in series between an input port and an output port, a plurality of parallel arm acoustic wave resonators electrically connected in parallel and electrically connected on first sides between respective ones of the plurality of series arm acoustic wave resonators and electrically connected on second sides to ground, and at least one additional acoustic wave resonator electrically connected in parallel to one of one of the plurality of series arm acoustic wave resonators or one of the plurality of parallel arm acoustic wave resonators and having a temperature coefficient of frequency (TCF) lower than a TCF of the acoustic wave resonator to which it is electrically connected in parallel.
    Type: Grant
    Filed: April 24, 2019
    Date of Patent: April 13, 2021
    Assignee: SKYWORKS SOLUTIONS, INC.
    Inventors: Tomoya Komatsu, Joji Fujiwara
  • Publication number: 20210067127
    Abstract: An acoustic wave device comprises a substrate including a piezoelectric material, interdigital transducer (IDT) electrodes disposed on an upper surface of the substrate. The IDT electrodes having gap regions, edge regions, and center regions. A duty factor of the IDT electrodes in the edge regions is greater than the duty factor of the IDT electrodes in the center regions. A first dielectric film is disposed above the IDT electrodes and an upper surface of the substrate. The first dielectric film has a greater thickness in portions of the center regions than in portions proximate the gap regions.
    Type: Application
    Filed: August 25, 2020
    Publication date: March 4, 2021
    Inventors: Riho Sasaki, Joji Fujiwara
  • Publication number: 20210067136
    Abstract: An acoustic wave device comprises a substrate including a piezoelectric material, and interdigital transducer (IDT) electrodes disposed on a surface of the substrate. The IDT electrodes have gap regions, edge regions, and center regions. A maximum width of the IDT electrodes in the gap regions is greater than the maximum width of the IDT electrodes in the edge regions, thereby achieving a velocity of an acoustic wave in the gap regions being greater than the velocity of the acoustic wave in the center regions, and the velocity of the acoustic wave in the center regions being greater than the velocity of the acoustic wave in the edge regions.
    Type: Application
    Filed: August 25, 2020
    Publication date: March 4, 2021
    Inventors: Joji Fujiwara, Riho Sasaki
  • Publication number: 20210067134
    Abstract: An acoustic wave device comprises a substrate including a piezoelectric material, interdigital transducer (IDT) electrodes disposed on a surface of the substrate, the IDT electrodes having gap regions, edge regions, and center regions, a first dielectric film having a lower surface disposed on the IDT electrodes and the surface of the substrate, and a material having a density greater than a density of the first dielectric film disposed above the gap regions of the IDT electrodes.
    Type: Application
    Filed: August 21, 2020
    Publication date: March 4, 2021
    Inventor: Joji Fujiwara
  • Patent number: 10491194
    Abstract: A filter device including a first filter having a first passband, and a second filter having a second passband, the first and second filters each being connected between a common contact and a respective signal contact, and the filter device configured to reduce spurious emissions generated in one filter due to propagation of Lamb waves in the other filter. In one example the first filter includes a SAW filter formed on a piezoelectric substrate, a SAW resonator formed on the piezoelectric substrate and connected in series between the common contact and the SAW filter, and a dielectric film formed over the piezoelectric substrate covering the SAW filter and the SAW resonator. The dielectric film has a first thickness over the SAW filter and a second, lesser, thickness over the SAW resonator, a difference between the first and second thicknesses being selected to suppress spurious emissions in the second passband generated by propagation of a Lamb wave in the SAW filter.
    Type: Grant
    Filed: January 15, 2019
    Date of Patent: November 26, 2019
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Tomoya Komatsu, Joji Fujiwara
  • Publication number: 20190341911
    Abstract: An electronic filter includes a plurality of series arm acoustic wave resonators electrically connected in series between an input port and an output port, a plurality of parallel arm acoustic wave resonators electrically connected in parallel and electrically connected on first sides between respective ones of the plurality of series arm acoustic wave resonators and electrically connected on second sides to ground, and at least one additional acoustic wave resonator electrically connected in parallel to one of one of the plurality of series arm acoustic wave resonators or one of the plurality of parallel arm acoustic wave resonators and having a temperature coefficient of frequency (TCF) lower than a TCF of the acoustic wave resonator to which it is electrically connected in parallel.
    Type: Application
    Filed: April 24, 2019
    Publication date: November 7, 2019
    Inventors: Tomoya Komatsu, Joji Fujiwara
  • Publication number: 20190149132
    Abstract: A filter device including a first filter having a first passband, and a second filter having a second passband, the first and second filters each being connected between a common contact and a respective signal contact, and the filter device configured to reduce spurious emissions generated in one filter due to propagation of Lamb waves in the other filter. In one example the first filter includes a SAW filter formed on a piezoelectric substrate, a SAW resonator formed on the piezoelectric substrate and connected in series between the common contact and the SAW filter, and a dielectric film formed over the piezoelectric substrate covering the SAW filter and the SAW resonator. The dielectric film has a first thickness over the SAW filter and a second, lesser, thickness over the SAW resonator, a difference between the first and second thicknesses being selected to suppress spurious emissions in the second passband generated by propagation of a Lamb wave in the SAW filter.
    Type: Application
    Filed: January 15, 2019
    Publication date: May 16, 2019
    Inventors: Tomoya Komatsu, Joji Fujiwara
  • Patent number: 10187039
    Abstract: A filter device that reduces spurious emissions generated in a frequency band 1.2 to 1.4 times greater than a center frequency of a passband of a filter. In one example the filter device includes a first filter connected between a common contact and a first signal contact and having a first passband, and a second filter connected between the common contact and a second signal contact and having a second passband with a center frequency in a range of 1.2 to 1.4 times greater than a center frequency of the first passband. The first filter includes a SAW filter formed on a piezoelectric substrate, a SAW resonator formed on the piezoelectric substrate and connected in series between the common contact and the SAW filter, and a dielectric film covering the SAW filter and SAW resonator, the dielectric film having a reduced thickness in a region corresponding to the SAW resonator.
    Type: Grant
    Filed: May 30, 2017
    Date of Patent: January 22, 2019
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Tomoya Komatsu, Joji Fujiwara
  • Patent number: 10141643
    Abstract: A high-frequency filter includes a first output to output a first signal, a first filter, a second filter, and a first matching circuit connected to an output of the first filter and to an output of the second filter. The first signal is provided to the first output from one of the output of the first filter and the output of the second filter via the first matching circuit. The first matching circuit includes a resonator connected in series between the first output and the output of only one of the first filter and the second filter.
    Type: Grant
    Filed: October 5, 2015
    Date of Patent: November 27, 2018
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Joji Fujiwara, Tetsuya Tsurunari, Tomoya Komatsu, Hiroyuki Nakamura
  • Patent number: 10135422
    Abstract: A filter device having improved attenuation and isolation characteristics. In one example the filter device has a common terminal, a first terminal, and a second terminal, and includes a first filter connected between the common terminal and the first terminal, a second filter connected between the common terminal and the second terminal, and an additional circuit including at least three IDT electrodes each connected to a respective one of a corresponding at least three connection points within the filter device, the at least three connection points being selected from a group consisting of the common terminal, the first terminal, the second terminal, a first node disposed between the plurality of first filter elements along a path extending between the common terminal and the first terminal, and a second node disposed between the plurality of second filter elements along a path extending between the common terminal and the second terminal.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: November 20, 2018
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Rei Goto, Joji Fujiwara, Tetsuya Tsurunari, Hiroyuki Nakamura
  • Patent number: 10097159
    Abstract: An acoustic wave element comprising a lithium tantalate substrate having the Euler angles (?, ?, ?), a first component ? satisfying 10°???50°; and an electrode disposed on the lithium tantalate substrate and configured to excite a main acoustic wave of wavelength ?, the electrode having a density ?M satisfying ?M??Ti where ?Ti represents a density of titanium (Ti), and a thickness hM of the electrode satisfies 0.141×exp(0.075?M)??hM?0.134? Embodiments of the present disclosure minimize a thickness of the electrode and suppress a spurious Rayleigh wave signal.
    Type: Grant
    Filed: March 11, 2016
    Date of Patent: October 9, 2018
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Tomoya Komatsu, Hidehito Shimizu, Joji Fujiwara, Tetsuya Tsurunari, Hiroyuki Nakamura
  • Patent number: 10044340
    Abstract: A ladder-type elastic wave filter includes an input terminal, an output terminal, and a ground terminal, a first series resonator and a second series resonator connected in series between the input terminal and the output terminal, and a first parallel resonator having a first terminal electrically connected to the series connection between the first series resonator and the second series resonator and a second terminal electrically connected to the ground terminal. A resonance frequency of the first parallel resonator is higher than a resonance frequency of both of the first series resonator and the second series resonator and lower than an antiresonance frequency of both of the first series resonator and the second series resonator.
    Type: Grant
    Filed: June 16, 2016
    Date of Patent: August 7, 2018
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Joji Fujiwara, Tetsuya Tsurunari, Tomoya Komatsu, Hiroyuki Nakamura
  • Publication number: 20170353174
    Abstract: A filter device that reduces spurious emissions generated in a frequency band 1.2 to 1.4 times greater than a center frequency of a passband of a filter. In one example the filter device includes a first filter connected between a common contact and a first signal contact and having a first passband, and a second filter connected between the common contact and a second signal contact and having a second passband with a center frequency in a range of 1.2 to 1.4 times greater than a center frequency of the first passband. The first filter includes a SAW filter formed on a piezoelectric substrate, a SAW resonator formed on the piezoelectric substrate and connected in series between the common contact and the SAW filter, and a dielectric film covering the SAW filter and SAW resonator, the dielectric film having a reduced thickness in a region corresponding to the SAW resonator.
    Type: Application
    Filed: May 30, 2017
    Publication date: December 7, 2017
    Inventors: Tomoya Komatsu, Joji Fujiwara
  • Patent number: 9819329
    Abstract: A ladder-type surface acoustic wave filter assembly includes a plurality of series resonators formed on a substrate and connected between an input terminal and an output terminal. A first series resonator has a lowest resonance frequency among the plurality of series resonator. A parallel resonator formed on the substrate and connected between the plurality of series resonators and the ground terminal. A dielectric film is coupled to at least one of the plurality of series resonators and has an inverse temperature coefficient of frequency to that of the substrate. A film thickness of the dielectric film in a region where the second series resonator is formed is smaller than a film thickness of the dielectric film in a region where the first series resonator is formed.
    Type: Grant
    Filed: October 26, 2015
    Date of Patent: November 14, 2017
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Tetsuya Tsurunari, Joji Fujiwara, Hiroyuki Nakamura, Hidekazu Nakanishi
  • Patent number: 9748924
    Abstract: An elastic wave device includes an interdigital transducer (IDT) electrode in contact with a piezoelectric substrate having a bus bar electrode region including one of a first bus bar electrode and a second bus bar electrode of the IDT electrode, an alternately disposed region where first electrode fingers are alternately disposed with second electrode fingers of the IDT electrode, and an intermediate region including one of the first electrode fingers and the second electrode fingers. A dielectric film is formed in at least part of the intermediate region and in contact with an upper surface of the IDT electrode. The dielectric film includes a medium in which an acoustic velocity of a transverse wave propagating in the dielectric film is lower than an acoustic velocity of a main elastic wave of the alternately disposed region. The dielectric film is not formed in the alternately disposed region.
    Type: Grant
    Filed: July 27, 2015
    Date of Patent: August 29, 2017
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Tomoya Komatsu, Hiroyuki Nakamura, Tetsuya Tsurunari, Joji Fujiwara, Hidekazu Nakanishi
  • Patent number: 9722576
    Abstract: An elastic wave filter has an unbalanced signal terminal, first and second balanced signal terminals, and first through fifth IDT electrodes arranged in ordinal order between a pair of grating reflectors. Wiring electrodes of the third and fifth IDT electrodes are disposed adjacent a ground electrode of the fourth IDT electrode, wiring electrodes of the second and third IDT electrodes are disposed adjacent one another, and ground electrodes of the first and second IDT electrodes are disposed adjacent one another. The unbalanced signal terminal is connected to the wiring electrodes of the first, third, and fifth IDT electrodes, and the first and second balanced signal terminals are connected to the wiring electrodes of the second and fourth IDT electrodes, respectively.
    Type: Grant
    Filed: November 17, 2015
    Date of Patent: August 1, 2017
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Joji Fujiwara, Tetsuya Tsurunari, Hiroyuki Nakamura, Rei Goto
  • Patent number: 9722573
    Abstract: A high-frequency filter including first and second signal terminals, a filter circuit having a passband and a stopband and being connected between the first signal terminal and the second signal terminal, and an additional circuit connected in parallel with the filter circuit between the first signal terminal and the second signal terminal. The filter circuit is configured to provide a first output signal responsive to receipt of an input signal. The additional circuit has an attenuation band within the stopband, and is configured to provide a second output signal responsive to receiving the input signal, the first and second output signals having phase components opposite to each other in the attenuation band.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: August 1, 2017
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Joji Fujiwara, Toru Jibu, Tomoya Komatsu, Hiroyuki Nakamura, Tetsuya Tsurunari, Kazunori Nishimura
  • Patent number: 9640750
    Abstract: In an acoustic wave device, an unnecessary high-order transverse mode wave is suppressed. The acoustic wave device includes a piezoelectric substrate, at least one pair of interdigital transducer (IDT) electrodes formed on the piezoelectric substrate, and a dielectric film which covers at least a part of the piezoelectric substrate and the IDT electrodes. The IDT electrodes each have a plurality of electrode fingers interleaved with each other. An acoustic velocity of an acoustic wave in the area in which the electrode fingers are interleaved with each other is greater than an acoustic velocity of an acoustic wave in an edge area including end portions of the electrode fingers.
    Type: Grant
    Filed: May 11, 2015
    Date of Patent: May 2, 2017
    Assignee: SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD.
    Inventors: Hidekazu Nakanishi, Hiroyuki Nakamura, Tetsuya Tsurunari, Joji Fujiwara
  • Publication number: 20170099043
    Abstract: A filter device having improved attenuation and isolation characteristics. In one example the filter device has a common terminal, a first terminal, and a second terminal, and includes a first filter connected between the common terminal and the first terminal, a second filter connected between the common terminal and the second terminal, and an additional circuit including at least three IDT electrodes each connected to a respective one of a corresponding at least three connection points within the filter device, the at least three connection points being selected from a group consisting of the common terminal, the first terminal, the second terminal, a first node disposed between the plurality of first filter elements along a path extending between the common terminal and the first terminal, and a second node disposed between the plurality of second filter elements along a path extending between the common terminal and the second terminal.
    Type: Application
    Filed: September 30, 2016
    Publication date: April 6, 2017
    Inventors: Rei Goto, Joji Fujiwara, Tetsuya Tsurunari, Hiroyuki Nakamura
  • Publication number: 20170093373
    Abstract: A high-frequency filter including first and second signal terminals, a filter circuit having a passband and a stopband and being connected between the first signal terminal and the second signal terminal, and an additional circuit connected in parallel with the filter circuit between the first signal terminal and the second signal terminal. The filter circuit is configured to provide a first output signal responsive to receipt of an input signal. The additional circuit has an attenuation band within the stopband, and is configured to provide a second output signal responsive to receiving the input signal, the first and second output signals having phase components opposite to each other in the attenuation band.
    Type: Application
    Filed: December 12, 2016
    Publication date: March 30, 2017
    Inventors: Joji Fujiwara, Toru Jibu, Tomoya Komatsu, Hiroyuki Nakamura, Tetsuya Tsurunari, Kazunori Nishimura