Patents Assigned to NTT Electronics Corporation
  • Patent number: 10983274
    Abstract: A broadband optical wavelength multiplexer/demultiplexer is provided. Two waveguides are arranged such that, in a case where a connection position where one of the two waveguides is connected to a first slab waveguide is set closer to the other waveguide by a channel frequency interval ?f, a central position between the two waveguides aligns with a central position on a connection end surface of the first slab waveguide, and two waveguide groups of an output waveguide are arranged such that a central position between the two waveguide groups aligns with a central position of a second slab waveguide, and an interval between a connection position where the other waveguide is connected to the first slab waveguide and the central position on the connection end surface of the first slab waveguide is set equal to an interval between a connection position where the waveguide groups are connected to the second slab waveguide.
    Type: Grant
    Filed: November 21, 2018
    Date of Patent: April 20, 2021
    Assignee: NTT ELECTRONICS CORPORATION
    Inventors: Daisuke Ogawa, Youichi Nishizato
  • Patent number: 10908356
    Abstract: An optical circuit board which is mounted with a loop-back circuit for returning aligning light to the fiber array in the vicinity of the fiber array connection end. Since an aligning loop-back circuit can be formed in an optical waveguide pattern, a production cost does not increase in comparison to an optical circuit board of the related art. The aligning light combined from the optical fiber to the aligning port of the optical circuit board is returned to the optical fiber around the loop-back circuit. Therefore, it is possible to perform alignment using the returned light. That is, alignment can be performed while being mounted on a package without installing a light-reflecting film or mirror.
    Type: Grant
    Filed: November 2, 2017
    Date of Patent: February 2, 2021
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tomohiro Nakanishi, Motoki Minami, Satoru Konno, Yuichi Suzuki, Teruaki Sato, Shigeo Nagashima, Shinji Mino, Motohaya Ishii, Shunichi Soma, Shin Kamei, Shuichiro Asakawa
  • Patent number: 10880193
    Abstract: A plurality of error correction circuits corrects errors of the data transmitted through the plurality of transmission lines. A combining portion combines the plurality of transmission lines to the plurality of error correction circuits. The plurality of transmission lines includes a first transmission line, and a second transmission line having a lower transmission characteristic than the first transmission line. The plurality of error correction circuits includes a first and a second error correction circuit having lower error correction capability and power consumption than the first error correction circuit. The combining portion uses a function to combine a plurality of error correction circuits with one transmission path, combines the first transmission line with the second error correction circuit at a higher rate than the first error correction circuit, and combines the second transmission line with the first error correction circuit at a higher rate than the second error correction circuit.
    Type: Grant
    Filed: December 15, 2017
    Date of Patent: December 29, 2020
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Mitsuteru Yoshida, Yasuyuki Endo, Etsushi Yamazaki, Katsuichi Oyama, Yasuharu Onuma, Masahito Tomizawa
  • Patent number: 10868617
    Abstract: A band division timing adjustment unit aligns timings of a plurality of signals, which are generated by dividing a received signal according to a plurality of frequency bands, in a time domain and combines the plurality of signals for which the timings have been aligned. A chromatic dispersion compensation unit compensates chromatic dispersion of an output signal of the band division timing adjustment unit for each of the plurality of frequency bands.
    Type: Grant
    Filed: October 6, 2017
    Date of Patent: December 15, 2020
    Assignees: NTT Electronics Corporation, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Mitsuteru Yoshida, Etsushi Yamazaki, Yoshiaki Kisaka, Masahito Tomizawa
  • Patent number: 10804857
    Abstract: An amplifier typically exemplified by a TIA is realized that provides an optimal band characteristic, that reduces the possibility of the oscillation, and that achieves a reduced dispersion of the band characteristics. An amplifier for amplifying an electric signal, comprising: a first buffer for amplifying the electric signal; a filter that is connected to an output of the first buffer and that includes a parallel circuit consisting of an inductor and a first capacity; and a second buffer connected to an output of the filter.
    Type: Grant
    Filed: May 15, 2018
    Date of Patent: October 13, 2020
    Assignees: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT ELECTRONICS CORPORATION
    Inventors: Masafumi Nogawa, Shinsuke Nakano, Hiroaki Sanjoh, Masatoshi Tobayashi, Yoshikazu Urabe, Masahiro Endo
  • Patent number: 10685095
    Abstract: A processing equipment includes a processing unit having a plurality of functions. A retaining unit retains a device identifier capable of identifying the processing equipment. An interface unit receives a function authentication key which is a code for setting a specific function among the plurality of functions to be enabled or disabled. A control unit sets the specific function to be enabled or disabled according to the function authentication key when a device identifier included in the received function authentication key coincides with the device identifier retained in the retaining unit.
    Type: Grant
    Filed: March 3, 2016
    Date of Patent: June 16, 2020
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Etsushi Yamazaki, Osamu Ishida, Kazuhito Takei, Yasuhiro Suzuki, Hideki Nishizawa
  • Patent number: 10649147
    Abstract: An optical module that is connectable to an optical fiber array and that can be packaged in a high density. Two package modules are mounted on a board, and optical waveguides in a Si photonic lightwave circuit mounted on the package module are connected to an optical fiber array fixed to an optical fiber block. Moreover, output end surfaces of the optical waveguides in the Si photonic lightwave circuit are perpendicular to a mount surface of the package module. The optical waveguides in the Si photonic lightwave circuit may be tilted at an appropriate angle with respect to a direction perpendicular to a right end surface. Moreover, the optical fiber block fixes optical fibers with the optical fibers tilted with respect to a direction perpendicular to an end surface connected to the Si photonic lightwave circuit.
    Type: Grant
    Filed: May 12, 2017
    Date of Patent: May 12, 2020
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tomohiro Nakanishi, Teruaki Sato, Motohaya Ishii, Satoru Konno, Yuichi Suzuki, Shigeo Nagashima, Shinji Mino, Shuichiro Asakawa, Hiroshi Fukuda, Shin Kamei, Shunichi Soma, Ken Tsuzuki, Mitsuo Usui, Takashi Saida
  • Patent number: 10637569
    Abstract: A method estimating transmission characteristics of an optical transmitter of a transmission unit and an optical receiver of a reception unit, including: estimating a temporary transfer or inverse transfer function of the optical receiver; estimating a transfer or inverse transfer function of the optical transmitter from first data acquired by the reception unit when a first known signal is transmitted from the transmission unit, and the estimated temporary transfer or inverse transfer function of the optical receiver, a difference between the first known signal and an original first known signal is minimized; and estimating a transfer or inverse transfer function of the optical receiver from second data acquired by the reception unit when a second known signal is transmitted from the transmission unit, and the estimated transfer or inverse transfer function of the optical transmitter, a difference between the second known signal and an original second known signal is minimized.
    Type: Grant
    Filed: November 8, 2017
    Date of Patent: April 28, 2020
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Akihiro Yamagishi, Tetsuya Maruyama, Masanori Nakamura, Asuka Matsushita, Shogo Yamanaka
  • Patent number: 10608743
    Abstract: A reception circuit includes a first adaptive compensator compensating distortion of a received signal. An adaptive compensation coefficient calculator includes a known-signal detector detecting first and second known-signals from the received signal, a second adaptive compensator compensating distortion of the received signal, a tap coefficient initial value calculator calculating an initial value of a tap coefficient of the second adaptive compensator by comparing the first known-signal with its true value, a first phase shift compensator compensating phase shift of an output of the second adaptive compensator using the second known-signal, and a tap coefficient calculator calculating tap coefficients of the first and second adaptive compensators by comparing at least one of the first and second known-signals compensated by the second adaptive compensator and the first phase shift compensator with its true value.
    Type: Grant
    Filed: May 26, 2017
    Date of Patent: March 31, 2020
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tomohiro Takamuku, Etsushi Yamazaki, Katsuichi Oyama, Yasuharu Onuma, Kazuhito Takei, Masanori Nakamura, Mitsuteru Yoshida, Masahito Tomizawa, Yoshiaki Kisaka
  • Publication number: 20200067598
    Abstract: A band division timing adjustment unit (10) aligns timings of a plurality of signals, which are generated by dividing a received signal according to a plurality of frequency bands, in a time domain and combines the plurality of signals for which the timings have been aligned. A chromatic dispersion compensation unit (17) compensates chromatic dispersion of an output signal of the band division timing adjustment unit (10) for each of the plurality of frequency bands.
    Type: Application
    Filed: October 6, 2017
    Publication date: February 27, 2020
    Applicants: NTT Electronics Corporation, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Mitsuteru YOSHIDA, Etsushi YAMAZAKI, Yoshiaki KISAKA, Masahito TOMIZAWA
  • Publication number: 20200036440
    Abstract: A method estimating transmission characteristics of an optical transmitter of a transmission unit and an optical receiver of a reception unit, including: estimating a temporary transfer or inverse transfer function of the optical receiver; estimating a transfer or inverse transfer function of the optical transmitter from first data acquired by the reception unit when a first known signal is transmitted from the transmission unit, and the estimated temporary transfer or inverse transfer function of the optical receiver, a difference between the first known signal and an original first known signal is minimized; and estimating a transfer or inverse transfer function of the optical receiver from second data acquired by the reception unit when a second known signal is transmitted from the transmission unit, and the estimated transfer or inverse transfer function of the optical transmitter, a difference between the second known signal and an original second known signal is minimized.
    Type: Application
    Filed: November 8, 2017
    Publication date: January 30, 2020
    Applicants: NTT Electronics Corporation, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Akihiro YAMAGISHI, Tetsuya MARUYAMA, Masanori NAKAMURA, Asuka MATSUSHITA, Shogo YAMANAKA
  • Publication number: 20200028767
    Abstract: A plurality of error correction circuits corrects errors of the data transmitted through the plurality of transmission lines. A combining portion combines the plurality of transmission lines to the plurality of error correction circuits. The plurality of transmission lines includes a first transmission line, and a second transmission line having a lower transmission characteristic than the first transmission line. The plurality of error correction circuits includes a first and a second error correction circuit having lower error correction capability and power consumption than the first error correction circuit. The combining portion uses a function to combine a plurality of error correction circuits with one transmission path, combines the first transmission line with the second error correction circuit at a higher rate than the first error correction circuit, and combines the second transmission line with the first error correction circuit at a higher rate than the second error correction circuit.
    Type: Application
    Filed: December 15, 2017
    Publication date: January 23, 2020
    Applicants: NTT Electronics Corporation, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Mitsuteru YOSHIDA, Yasuyuki ENDO, Etsushi YAMAZAKI, Katsuichi OYAMA, Yasuharu ONUMA, Masahito TOMIZAWA
  • Patent number: 10523335
    Abstract: Fourier transform is performed on a reception signal to obtain a first calculation value. Fourier transform is performed on a known signal to obtain a second calculation value. The first calculation value is divided by the second calculation value to obtain a third calculation value. Inverse Fourier transform is performed on the third calculation value to obtain a fourth calculation value. A maximum value of an amplitude of the fourth calculation value and a sample point at which the maximum value is obtained are detected. The position of the known signal in the reception signal is detected from the sample point at which the maximum value is obtained.
    Type: Grant
    Filed: June 21, 2017
    Date of Patent: December 31, 2019
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Yasuharu Onuma, Etsushi Yamazaki, Tomohiro Takamuku, Masahiro Tachibana, Mitsuteru Yoshida, Masahito Tomizawa, Seiji Okamoto
  • Patent number: 10422719
    Abstract: A Fourier-transformer performs Fourier transform on a filter coefficient output from an adaptive equalizer which comprises a finite impulse response filter of N taps (N represents an integer of 2 or more) in a time direction. An eigenvalue sum calculator integrates a frequency-differentiation result of the Fourier-transformed filter coefficient and a complex conjugate of the Fourier-transformed filter coefficient to calculate a matrix, and calculates a sum of two eigenvalues of the matrix. A proportionality factor calculator calculates a proportionality factor for frequency from the sum of the two eigenvalues.
    Type: Grant
    Filed: October 4, 2016
    Date of Patent: September 24, 2019
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Etsushi Yamazaki, Tomohiro Takamuku, Yuki Yoshida, Mitsuteru Yoshida, Koki Shibahara, Kengo Horikoshi, Yoshiaki Kisaka
  • Patent number: 10419127
    Abstract: A symbol phase difference compensating portion (6) calculates a first phase difference which is a phase difference between a known pattern extracted from a received signal and a true value of the known pattern and performs phase compensation for the received signal based on the first phase difference. A tentative determination portion (12) tentatively determines an output signal of the symbol phase difference compensating portion (6) to acquire an estimated value of a phase. A first phase difference acquiring portion (13) acquires a second phase difference which is a phase difference between a phase of the output signal and the estimated value of the phase acquired by the tentative determination portion (12). A first phase difference compensating portion (14) performs phase compensation for the output signal based on the second phase difference.
    Type: Grant
    Filed: April 13, 2017
    Date of Patent: September 17, 2019
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Etsushi Yamazaki, Hiroyukl Nouchi, Yasuharu Onuma, Tomohiro Takamuku, Katsuichi Oyama, Kazuhito Takei, Masahito Tomizawa, Yoshiaki Kisaka, Mltsuteru Yoshida, Masanori Nakamura
  • Patent number: 10397579
    Abstract: A position coordinate difference computing unit (5a to 5c) calculates position coordinate differences between position coordinates of the output digital signals and position coordinates of the input digital signals adjacent to the position coordinates. An FIR coefficient memory (13a to 13c) stores FIR coefficients of an FIR-LPF and outputs FIR coefficients corresponding to position coordinate differences between a fixed number of the output digital signals adjacent to the position coordinates of the output digital signals and the output digital signals. A control unit (11) supplies a group of the FIR coefficients and a group of the input digital signals corresponding to the respective position coordinate differences to the parallel FIR calculator (4) in predetermined order when the position coordinate differences corresponding to two or more different output digital signals are concurrently computed.
    Type: Grant
    Filed: May 9, 2013
    Date of Patent: August 27, 2019
    Assignee: NTT ELECTRONICS CORPORATION
    Inventors: Yuichiro Koike, Yasuhiro Yamada
  • Patent number: 10396895
    Abstract: In a method in which a compensation coefficient calculating portion (6) calculates a compensation coefficient of a compensation portion (5) which compensates transmission characteristics of a signal, a known signal is extracted from the signal. Next, a pseudo-random number is added to the extracted known signal. Next, the compensation coefficient is calculated by comparing a true value of the known signal with the known signal to which the pseudo-random number is added.
    Type: Grant
    Filed: April 26, 2017
    Date of Patent: August 27, 2019
    Assignee: NTT ELECTRONICS CORPORATION
    Inventors: Tomohiro Takamuku, Etsushi Yamazaki, Yuki Yoshida, Katsuichi Oyama, Yasuharu Onuma, Akihiro Yamagishi
  • Patent number: 10389452
    Abstract: A coherent optical reception device includes a local oscillation laser that supplies laser light, a coherent optical reception front-end unit that receives a multi-level modulated optical signal, demodulates the optical signal on the basis of the laser light, and converts a demodulated optical signal into an electrical analog signal, an analog-to-digital converter that converts the analog signal into a digital signal, a compensation unit that compensates for an influence of dispersion due to a wavelength or a polarized wave of the optical signal and recovers a carrier phase of the digital signal, a constellation distortion compensation unit that compensates for constellation distortion of the multi-level modulation included in the digital signal in which an influence of dispersion is compensated for by the compensation unit, and an error correction decoding unit that performs error correction of the digital signal in which the constellation distortion is compensated for.
    Type: Grant
    Filed: October 17, 2016
    Date of Patent: August 20, 2019
    Assignees: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT Electronics Corporation
    Inventors: Kengo Horikoshi, Mitsuteru Yoshida, Seiji Okamoto, Eiichi Hosoya, Etsushi Yamazaki, Yasuharu Onuma, Tomohiro Takamuku, Naoki Miura, Sadayuki Yasuda
  • Patent number: 10374718
    Abstract: An I component compensation unit calculates an I component in which a distortion has been compensated, by forming a first polynomial expressing the distortion of the I component based on an I component and a Q component of a quadrature modulation signal and multiplying each term of the first polynomial by a first coefficient. A Q component compensation unit calculates a Q component in which a distortion has been compensated, by forming a second polynomial expressing the distortion of the Q component based on the I component and the Q component of the quadrature modulation signal and multiplying each term of the second polynomial by a second coefficient. A coefficient calculation unit calculates the first and second coefficients by comparing outputs of the I component compensation unit and the Q component compensation unit and a known signal.
    Type: Grant
    Filed: June 21, 2017
    Date of Patent: August 6, 2019
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Yasuharu Onuma, Etsushi Yamazaki, Hiroyuki Nouchi, Tomohiro Takamuku, Katsuichi Oyama, Kazuhito Takei, Masanori Nakamura, Mitsuteru Yoshida, Masahito Tomizawa
  • Patent number: 10367100
    Abstract: A semiconductor element capable of adjusting a barrier height ?Bn and performing zero-bias operation and impedance matching with an antenna for improving detection sensitivity of high-frequency RF electric signals, a method of manufacturing the same, and a semiconductor device having the same. In the semiconductor element, a concentration of InGaAs (n-type InGaAs layer) is intentionally set to be high over a range for preventing the “change of the barrier height caused by the bias” described above up to a deep degeneration range. An electron Fermi level (EF) increases from a band edge of InGaAs (n-type InGaAs layer) to a band edge of InP (InP depletion layer).
    Type: Grant
    Filed: August 13, 2015
    Date of Patent: July 30, 2019
    Assignee: NTT ELECTRONICS CORPORATION
    Inventors: Makoto Shimizu, Hiroki Itoh, Tadao Ishibashi, Isamu Kotaka