Feedback Patents (Class 398/209)
  • Patent number: 11923901
    Abstract: An electronic device may include an antenna that conveys wireless signals at frequencies greater than 100 GHz. The antenna may include a radiating element coupled to a uni-travelling-carrier photodiode (UTC PD). An optical path may illuminate the UTC PD using a first optical local oscillator (LO) signal and a second optical LO signal. An optical phase shift may be applied to the first optical LO signal. A Mach-Zehnder modulator (MZM) may be interposed on the optical path. During signal transmission, the MZM may modulate wireless data onto the second optical LO signal while control circuitry applies a first bias voltage to the UTC PD. During signal reception, the control circuitry may apply a second bias voltage to the UTC PD that configures the UTC PD to convert received wireless signals into intermediate frequency signals and/or optical signals.
    Type: Grant
    Filed: June 7, 2022
    Date of Patent: March 5, 2024
    Assignee: Appli Inc.
    Inventors: Zdravko Boos, Bertram R Gunzelmann
  • Patent number: 11882204
    Abstract: An optoelectronic module may include an optical receiver optically coupled with an optical fiber. The optical receiver may be configured to receive time synchronization signals from the optical fiber. The time synchronization signals may be frequency modulated, wavelength modulated, or amplitude modulated and may be received along with received data signals. A time synchronization signal detection module may be communicatively coupled to the optical receiver. The time synchronization signal detection module may be configured to receive the time synchronization signals that are transmitted through the optical fiber and detect frequency modulations, wavelength modulations, or amplitude modulations to recover the time synchronization signals.
    Type: Grant
    Filed: June 29, 2021
    Date of Patent: January 23, 2024
    Assignee: II-VI DELAWARE, INC.
    Inventors: Puhui Miao, Huade Shu, Leo Lin
  • Patent number: 11784721
    Abstract: A reception device includes a measurement unit that measures a first number of times for which a first phase and a first reverse phase based on a differential signal obtained by amplifying a signal based on noise intersect with each other, the first reverse phase being a reverse phase of the first phase, an oscillator that transmits a first signal, a comparison unit that compares the first number of times with a predetermined first reference value, and a signal output unit that outputs a second signal indicating that an optical signal has been received when the first number of times and the first reference value coincide with each other. The measurement unit resets the first number of times when the first signal is received.
    Type: Grant
    Filed: August 20, 2020
    Date of Patent: October 10, 2023
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takanori Kawanaka, Hiroyuki Ozaki, Yusuke Mitsui
  • Patent number: 11770118
    Abstract: In one embodiment, a system includes a power delivery (“PD”) controller in a USB Type-C system that includes a configuration channel (“CC”), PD preamble detector, and a power-usage circuit. The PD controller includes a CC input that receives a PD message. The PD preamble detector is configured to detect a PD message preamble based in part upon a power of a filtered PD message and communicates a wake-up signal to the power-usage circuit in response to detecting a PD message preamble. The power-usage circuit is configured to exit a low-power mode in response to receiving the wake-up signal.
    Type: Grant
    Filed: November 10, 2020
    Date of Patent: September 26, 2023
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Deric Wayne Waters, Roy Alan Hastings
  • Patent number: 11575355
    Abstract: A multi-stage transimpedance amplifier (TIA) with an adjustable input linear range is disclosed. The TIA includes a first stage, configured to convert a single-ended current signal from an optical sensor of a receiver signal chain to a single-ended voltage signal, and a second stage, configured to convert the single-ended voltage signal provided by the first stage to a differential signal. In such a TIA, the input linear range may be adjusted using a clamp that is programmable with an output offset current to keep the second stage of the TIA from overloading and to maintain a linear transfer function without compression.
    Type: Grant
    Filed: January 14, 2022
    Date of Patent: February 7, 2023
    Assignee: ANALOG DEVICES INTERNATIONAL UNLIMITED COMPANY
    Inventors: Joseph Adut, Jeremy Wong, Eugene L. Cheung, Brian D. Hamilton, Gregory A. Fung
  • Patent number: 11463177
    Abstract: A system and method for controlling optical receiver operation in response to a received optic signal power level that includes providing an optic signal receiver having operation determined by one or more system settings. During operation, the optic signal is received and converted to an electrical signal. The electrical signal is evaluated to determine a power level of the electrical signal. Responsive to the power level of the electrical signal exceeding a first predetermined threshold, adjusting a first system setting and responsive to the power level of the received electrical signal decreasing below a second predetermined threshold, adjusting the first system setting. Then, responsive to the power level of the received electrical signal exceeding a third predetermined threshold, adjusting a second system setting and responsive to the power level of the received electrical signal decreasing below a fourth predetermined threshold, adjusting the second system setting.
    Type: Grant
    Filed: April 26, 2021
    Date of Patent: October 4, 2022
    Assignee: MACOM Technology Solutions Holdings, Inc.
    Inventors: Vasilis Papanikolaou, Jeffrey Allen
  • Patent number: 11378663
    Abstract: An example circuit includes a light detector and a biasing capacitor having (i) a first terminal that applies to the light detector an output voltage that can either bias or debias the light detector and (ii) a second terminal for controlling the output voltage. The circuit includes a first transistor connected to the second terminal of the biasing capacitor and configured to drive the output voltage to a first voltage level above a biasing threshold of the light detector and thereby biasing the light detector. The circuit includes a second transistor connected to the second terminal of the biasing capacitor and configured to drive the output voltage to a second voltage level below the biasing threshold of the light detector and thereby debiasing the light detector. The second voltage is a non-zero voltage that corresponds to a charge level of the biasing capacitor.
    Type: Grant
    Filed: November 26, 2019
    Date of Patent: July 5, 2022
    Assignee: Waymo LLC
    Inventors: Pierre-yves Droz, Vadim Gutnik
  • Patent number: 11381318
    Abstract: An optical receiver includes a photodiode, a transimpedance amplifier (TIA), a slope detection circuit, and a logic circuit. The TIA includes an output stage and a feedback amplifier and is coupled to the photodiode. The slope detection circuit is coupled to the feedback amplifier and configured to monitor a feedback signal from the feedback amplifier. The slope detection circuit is configured to provide, in response to a slope in the feedback signal being detected, a first slope-status signal indicating the slope is detected. The logic circuit is coupled to the slope detection circuit and is coupled to the output stage of the TIA. The logic circuit is configured to squelch the output stage of the TIA in response to the first slope-status signal.
    Type: Grant
    Filed: July 30, 2021
    Date of Patent: July 5, 2022
    Assignee: II-VI DELAWARE, INC
    Inventors: Dinup Sukumaran, Ken C. Kiong
  • Patent number: 11283710
    Abstract: The present subject matter relates to methods, circuitry and equipment providing a multi-functional, cost effective, media independent, open platform device for communication services using differential signaling interfaces. The methods, circuitry and equipment comprise a plurality of input amplifiers, output amplifiers, and retimers. A non-blocking cross-point switch may be used to switch any differential signals from the cross-point switch input to output. The device aggregates communication services from a plurality of lower service capacity connectors and interfaces to a single higher capacity connector and interfaces. The device can establish a demarcation point with a single device capable of supporting any communication services, any physical media interfaces, from any location.
    Type: Grant
    Filed: August 27, 2020
    Date of Patent: March 22, 2022
    Inventor: Sean Iwasaki
  • Patent number: 11265139
    Abstract: An optical communication device including a GPS receiver receiving and outputting a GPS signal from a satellite; a main controller configured to generate and output synchronization data based on the GPS signal; and an optical transceiver configured to generate an optical signal by superposing input payload data and the synchronization data, and to output the optical signal, wherein a first communication channel corresponding to the payload data and a second communication channel corresponding to the synchronization data are different communication channels. According to embodiments, GPS information for synchronization together with payload data, which is information to be transmitted, may be efficiently transmitted between optical communication devices located in remote locations without separate wavelength allocation and connection of an optical cable, by using an auxiliary management and control channel (AMCC).
    Type: Grant
    Filed: October 22, 2020
    Date of Patent: March 1, 2022
    Assignee: SOLiD, INC.
    Inventor: Bum Soo Park
  • Patent number: 11262637
    Abstract: A frequency diverse distributed Mach-Zehnder Interferometer may include an optical modulator on a chip, with the modulator comprising a plurality of diodes arranged along a waveguide and with each diode driven by two or more drivers. An optical signal may be received in the waveguide, and a first modulating electrical signal may be applied to a first of the plurality of diodes using a first driver and a second modulating electrical signal may be applied to the first of the plurality of diodes using a second driver. The first electrical signal may be different from the second modulating electrical signal. The second electrical signal may have a larger voltage swing than the first electrical signal. The first electrical signal voltage swing may be 0.85 volts and the second electrical signal voltage swing may be 1.5 volts, for example. The first and second electrical signals may have different frequencies.
    Type: Grant
    Filed: January 14, 2020
    Date of Patent: March 1, 2022
    Assignee: Luxtera LLC
    Inventor: Brian Welch
  • Patent number: 11246200
    Abstract: LED drive control circuitry according to one embodiment outputs an LED drive control signal serving as driving a light emitting diode included in a photocoupler that performs insulation communication in synchronization with a reference clock signal. The LED drive control circuit includes a duty cycle changer that changes a duty cycle of the LED drive control signal in accordance with the reference clock signal and a signal synchronized with the reference clock signal.
    Type: Grant
    Filed: August 21, 2020
    Date of Patent: February 8, 2022
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventor: Katsuyuki Ikeuchi
  • Patent number: 11212086
    Abstract: The present invention, which is used for continuous variable quantum key distribution (CVQKD) with asynchronous local oscillators, relates to a system for performing a phase compensation of a scheme of using LO phase estimation and feedback at a receiver (Bob) using a pilot signal from a transmitter (Alice) and a scheme of measuring quantum state data using an LO having a predetermined phase at the receiver (Bob) and estimating and feeding back an LO phase through multi-dimensional reconciliation (MDR).
    Type: Grant
    Filed: April 13, 2018
    Date of Patent: December 28, 2021
    Assignee: Korea Advanced Institute of Science and Technology
    Inventors: June Koo Rhee, Ii Hwan Park, Kyong Chun Lim, Jun Sang Oh, Yong Seen Kim
  • Patent number: 11092824
    Abstract: A method of controlling an optical amplifying system that processes an optical signal with the PAM4 mode is disclosed. The optical amplifying system includes a variable optical attenuator (VOA) and a semiconductor optical amplifier (SOA). The VOA attenuates the optical signal such that a maximum optical power thereof corresponding to one of the physical levels of the PAM4 signal becomes equal to a preset optical level for which the SOA may be linearly operable. The SOA may amplify the thus attenuated optical signal with a fixed optical gain.
    Type: Grant
    Filed: July 18, 2018
    Date of Patent: August 17, 2021
    Assignee: SUMITOMO ELECTRIC DEVICE INNOVATIONS, INC.
    Inventor: Ryota Teranishi
  • Patent number: 10931485
    Abstract: An adaptive equalization circuit includes: a first filter configure to perform filtering on an input signal based on a tap coefficient; an applying circuit configured to apply, to the signal, noise outside a band of the signal; and a controller configured to set, for the first filter, the tap coefficient that compensates for transmission line characteristics of the signal, based on the signal to which the noise is applied by the applying circuit.
    Type: Grant
    Filed: January 3, 2020
    Date of Patent: February 23, 2021
    Assignee: FUJITSU LIMITED
    Inventors: Yuya Imoto, Kazuhiko Hatae, Nobukazu Koizumi, Yasuo Ohtomo, Masashi Sato, Daisuke Sasaki
  • Patent number: 10797658
    Abstract: An optical receiver circuit is disclosed, including a photodiode, an output terminal, a first amplifier stage, and an electrostatic discharge (ESD) protection circuit. The photodiode may generate a receiver current based on received optical signals. The first amplifier stage may be coupled between the photodiode and the output terminal and include a first inductor coupled between the photodiode and an input of a first inverter, and a second inductor coupled between the input of the first inverter and a first resistor. The first resistor may be coupled between the second inductor and an output of the first inverter. ESD protection circuit may be coupled to the input of the first inverter. The output terminal may generate an output signal based at least in part on the output of the first inverter.
    Type: Grant
    Filed: July 29, 2019
    Date of Patent: October 6, 2020
    Assignee: Xilinx, Inc.
    Inventor: Mayank Raj
  • Patent number: 10615763
    Abstract: In conventional optical receivers the dynamic range is obtained by using variable gain amplifiers (VGA) with a fixed trans-impedance amplifier (TIA) gain. To overcome the SNR problems inherent in conventional receivers an improved optical receiver comprises an automatic gain control loop for generating at least one gain control signal for controlling gain of both the VGA and the TIA. Ideally, both the resistance and the gain of the TIA are controlled by a gain control signal.
    Type: Grant
    Filed: July 29, 2019
    Date of Patent: April 7, 2020
    Assignee: Elenion Technologies, LLC
    Inventors: Mostafa Ahmed, Alexander Rylyakov
  • Patent number: 10606004
    Abstract: Embodiments herein may relate to an optoelectronic receiver that includes a photonic integrated circuit (PIC) coupled with a light source. Respective PIC sections of the PIC may include a photodiode and a junction capacitor. The optoelectronic receiver may further include an electronic integrated circuit (EIC) coupled with the PIC. Respective EIC sections of the EIC may be communicatively coupled to respective ones of the PIC sections. Other embodiments may be described and/or claimed.
    Type: Grant
    Filed: June 1, 2018
    Date of Patent: March 31, 2020
    Assignee: Intel Corporation
    Inventors: Jahnavi Sharma, Ganesh Balamurugan, Hao Li, Meer Nazmus Sakib, Haisheng Rong
  • Patent number: 10520548
    Abstract: A system and method for monitoring, testing or configuring electrical devices includes an input amplifier having an input connected to a device load line to generate an output linearly proportional to a voltage on the load line. An output of the input amplifier is connected to a photodiode in an optical path with a phototransistor. The phototransistor generates an output proportional to light generated by the photodiode, and this output is amplified and passed to an analog-to-digital converter. The converter generates a digital voltage level corresponding to the amplified output of the phototransistor. Digital temperature information is used to further enhance linearity of a generated digital voltage level. Multiple quantum well photodiodes further improve measurement linearity.
    Type: Grant
    Filed: October 17, 2017
    Date of Patent: December 31, 2019
    Assignee: Toshiba America Electronic Components, Inc.
    Inventor: Jurgis Astrauskas
  • Patent number: 10404499
    Abstract: Embodiments of the present disclosure may relate to a transmitter that includes a baseband dispersion compensator to perform baseband dispersion compensation on an input signal. Embodiments may also include a receiver that includes a radio frequency (RF) dispersion compensator to perform RF dispersion compensation. Embodiments may also include a dielectric waveguide coupled with the transmitter and the receiver, the dielectric waveguide to convey the RF signal from the transmitter to the receiver. Other embodiments may be described and/or claimed.
    Type: Grant
    Filed: December 22, 2016
    Date of Patent: September 3, 2019
    Assignee: Intel Corporation
    Inventors: Georgios C. Dogiamis, Emanuel Cohen, Sasha N. Oster, Telesphor Kamgaing
  • Patent number: 10333622
    Abstract: The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using PAM format(s) over optical communication networks. A feedback mechanism is provided for adjusting the transmission power levels. There are other embodiments as well.
    Type: Grant
    Filed: March 9, 2018
    Date of Patent: June 25, 2019
    Assignee: Inphi Corporation
    Inventors: Sudeep Bhoja, Chao Xu, Hari Shankar
  • Patent number: 10285160
    Abstract: The present application discloses a method for transmitting, by a base station, a broadcast channel through a massive multiple-input multiple output (MIMO) antenna in a wireless communication system. Specifically, the method comprises the steps of: selecting broadcast channel dedicated antenna elements from among all antenna elements of the massive MIMO antenna; and transmitting the broadcast channel by performing a beamforming using the broadcast channel dedicated antenna elements. In the present invention, the power applied to the broadcast channel dedicated antenna elements in greater than the voltage applied to the remaining antenna elements.
    Type: Grant
    Filed: December 17, 2013
    Date of Patent: May 7, 2019
    Assignee: LG ELECTRONICS INC.
    Inventors: Soocheol Kyeong, Sungho Park, Kyunghaeng Lee, Hyunsoo Ko, Sunam Kim
  • Patent number: 10224879
    Abstract: A peak detector utilizes two choppers to cancel offset voltage of a transconductance amplifier, so the influence of the offset voltage is preventable and the peak detection accuracy of the peak detector can be improved significantly.
    Type: Grant
    Filed: December 26, 2017
    Date of Patent: March 5, 2019
    Assignee: NATIONAL SUN YAT-SEN UNIVERSITY
    Inventors: Chua-Chin Wang, Deng-Shian Wang, Hao-Chun Huang
  • Patent number: 9948396
    Abstract: The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using PAM format(s) over optical communication networks. A feedback mechanism is provided for adjusting the transmission power levels. There are other embodiments as well.
    Type: Grant
    Filed: September 29, 2016
    Date of Patent: April 17, 2018
    Assignee: INPHI CORPORATION
    Inventors: Sudeep Bhoja, Chao Xu, Hari Shankar
  • Patent number: 9915614
    Abstract: Methods, systems, and devices are disclosed for molecular capture, manipulation, and analysis. In one aspect, a device to aggregate and characterize particles in a fluid includes an electrically insulative substrate including a channel to carry an electrically conducting fluid containing particles, electrodes located in the channel forming a nanoscale opening and including an insulating layer over their surface at the opening, a first circuit to apply a non-uniform ac electric field and a dc bias signal across the electrodes, in which the applied non-uniform ac electric field produces a positive dielectrophoretic force to aggregate the particles in a trapping region including the opening and adjacent region, a second circuit to detect changes in a dc current caused by at least some of the particles in the trapping region, and an optical device that directs a coherent light beam on the opening to determine Raman spectra of the particles in the trapping region.
    Type: Grant
    Filed: April 26, 2013
    Date of Patent: March 13, 2018
    Assignees: ACADEMIA SINICA, MAX-PLANCK-INSTITUT FUR EISENFORSCHUNG GMBH
    Inventors: Chia-Fu Chou, Lesser-Rojas Leonardo, Ming-Lee Chu, Andreas Erbe
  • Patent number: 9843295
    Abstract: Disclosed is a transimpedance amplifier. The transimpedance amplifier includes an inverter configured to have a feedback resistor and amplify a signal provided to an input side, and a common gate amplifier configured to be connected to the inverter in cascade and amplify an output of the inverter, wherein the signal provided to the input side is fed forward to a gate of the common gate amplifier through a gate resistor.
    Type: Grant
    Filed: June 16, 2015
    Date of Patent: December 12, 2017
    Assignee: EWHA UNIVERSITY-INDUSTRY COLLABORATION FOUNDATION
    Inventors: Sung Min Park, Seung Hoon Kim
  • Patent number: 9774392
    Abstract: Systems and methods using a polarimetric measurement device to localize a source of one or more State of Polarization (SOP) transients affecting one or more optical fibers are disclosed. The method includes transmitting a signal into a fiber in a first direction; receiving, at the polarimetric measurement device, the signal from one of the fiber and another fiber collocated in a bundle with the fiber in a second direction; and processing data from the polarimetric measurement device to determine a location of the one or more SOP transients. The processing can include detecting a presence of the one or more SOP transients based on a first signature and its echo seen in the data; and converting a time between the echoes into a distance.
    Type: Grant
    Filed: September 25, 2015
    Date of Patent: September 26, 2017
    Assignee: Ciena Corporation
    Inventors: David R. Doucet, Douglas Charlton, David C. Bownass, Maurice S. O'Sullivan, Joanne Wakefield
  • Patent number: 9602202
    Abstract: Methods and systems for replicating current outputs from a photodetector include using a transimpedance (TIA) amplifier to directly generate a TIA output voltage that is linear with optical power at the photodetector. Additionally, a first logarithmic amplifier is used to generate a first output voltage from the photodetector current and a second logarithmic amplifier is used to generate a second voltage from a copy of the photodetector current. The first voltage and the second voltage may be linear in some cases with the optical power in decibels.
    Type: Grant
    Filed: September 9, 2015
    Date of Patent: March 21, 2017
    Assignee: Fujitsu Limited
    Inventors: Christopher Mesibov, Noah Gottfried, Idan Mandelbaum
  • Patent number: 9479264
    Abstract: An apparatus comprising a receiver optical subassembly (ROSA) configured to receive an optical signal, wherein the ROSA comprises an optical-electrical (O/E) converter configured to convert the optical signal into an electrical signal, and a processor coupled to the ROSA and configured to calibrate an O/E converter bias, wherein calibrating the O/E converter bias comprises reading an initial O/E converter dark current measurement, adjusting the O/E converter bias with a voltage step, reading an adjusted O/E converter dark current measurement after the voltage step adjustment, and monitoring an O/E converter dark current change rate by subtracting the initial O/E converter dark current measurement from the adjusted O/E converter dark current measurement.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: October 25, 2016
    Assignee: Futurewei Technologies, Inc.
    Inventors: Ning Cheng, Guo Wei, Zhenxing Liao
  • Patent number: 9467231
    Abstract: The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using PAM format(s) over optical communication networks. A feedback mechanism is provided for adjusting the transmission power levels. There are other embodiments as well.
    Type: Grant
    Filed: January 19, 2015
    Date of Patent: October 11, 2016
    Assignee: INPHI CORPORATION
    Inventors: Sudeep Bhoja, Chao Xu, Hari Shankar
  • Patent number: 9270386
    Abstract: Techniques are disclosed for detecting image depth in three-dimensional (3-D) surface imaging. The disclosed techniques can be used, for example, to provide structured light encoded with a coded word that includes error-correcting code (ECC). The ECC is effectively configured to detect and correct data errors as may result, for example, from the presence of ambient light and/or camera-noise-causing errors during imaging. In an example case, the coded word is a 15-bit pattern provided in a 3×5 matrix and including: (1) nine data bits of disparity code; (2) five ECC bits for correcting an error and detecting two errors; and (3) one 8-bit/10-bit encoding bit to ensure the presence of a transient pixel in the data for white threshold level detection. Greater or lesser bit quantities and varied bit partitioning matrices can be provided, as desired. In some cases, imaging robustness and/or power usage can be improved using the disclosed techniques.
    Type: Grant
    Filed: June 24, 2013
    Date of Patent: February 23, 2016
    Assignee: INTEL CORPORATION
    Inventor: David D. Bar-On
  • Patent number: 9237002
    Abstract: One embodiment includes a circuit system. The system includes a power detector configured to convert an AC signal to a DC signal corresponding to a power amplitude associated with the AC signal. The AC signal can include a periodic signal power null. The system also includes a null-gating circuit comprising a logic switch that is activated to enable sampling of an amplitude of the DC signal and that is deactivated during the periodic signal power null. The system also includes an analog-to-digital converter (ADC) configured to convert the sampled DC signal to a digital signal. The system further includes a processor configured to process the digital signal.
    Type: Grant
    Filed: January 30, 2014
    Date of Patent: January 12, 2016
    Assignee: Imagine Communications Corp.
    Inventor: William Ty Chizevsky
  • Patent number: 9236851
    Abstract: A direct conversion radio-frequency (RF) receiver includes a controller and an adaptive continuous-time filter. The adaptive continuous-time filter receives a multiple-bit control signal generated by the controller to adjust a characteristic of the continuous-time filter. The controller generates the multiple-bit control signal in response to process variation in the semi-conductor material used to implement the controller and the adaptive continuous-time filter. A method for tuning an adaptive continuous-time filter comprises determining a RC time constant, converting the RC time constant to a digital word, comparing a select bit of the digital word to a respective bit of a predetermined reference word to generate a control bit, applying the control bit to an adjustable element to modify the RC time constant, repeating the determining, converting, comparing and applying steps until the control bits generate an output word and providing the output word to the adaptive continuous-time filter.
    Type: Grant
    Filed: February 6, 2012
    Date of Patent: January 12, 2016
    Assignee: Skyworks Solutions, Inc.
    Inventors: Edward Youssoufian, Aly M. Ismail, Geoffrey Hatcher
  • Patent number: 9197324
    Abstract: The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using PAM format(s) over optical communication networks. A feedback mechanism is provided for adjusting the transmission power levels. There are other embodiments as well.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: November 24, 2015
    Assignee: Inphi Corporation
    Inventors: Sudeep Bhoja, Chao Xu, Hari Shankar
  • Patent number: 9116810
    Abstract: Described are methods and circuits for margin testing digital receivers. These methods and circuits prevent margins from collapsing in response to erroneously received data, and can thus be used in receivers that employ historical data to reduce intersymbol interference (ISI). Some embodiments detect receive errors for input data streams of unknown patterns, and can thus be used for in-system margin testing. Such systems can be adapted to dynamically alter system parameters during device operation to maintain adequate margins despite fluctuations in the system noise environment due to e.g. temperature and supply-voltage changes. Also described are methods of plotting and interpreting filtered and unfiltered error data generated by the disclosed methods and circuits. Some embodiments filter error data to facilitate pattern-specific margin testing.
    Type: Grant
    Filed: July 17, 2014
    Date of Patent: August 25, 2015
    Assignee: Rambus Inc.
    Inventors: Andrew Ho, Vladimir Stojanovic, Bruno W. Garlepp, Fred F. Chen
  • Patent number: 9071478
    Abstract: A method for performing adaptive equalization includes: dynamically detecting current levels of a plurality of sets of pattern levels respectively corresponding to a plurality of data patterns, wherein each set of the sets of pattern levels includes a previous level, a current level, and a next level respectively corresponding to one of the plurality of data patterns; and dynamically calculating a plurality of data decision levels according to the current levels of the sets of pattern levels, for use of data decision, wherein each data decision level of at least one portion of the plurality of data decision levels is not equal to zero, and the data decision levels are dynamically adjusted in accordance with the current levels of the sets of pattern levels, in order to enhance a signal-to-noise ratio (SNR). An associated method for performing adaptive equalization is also provided. Associated apparatus are also provided.
    Type: Grant
    Filed: May 24, 2011
    Date of Patent: June 30, 2015
    Assignee: MEDIATEK INC.
    Inventors: Yan-Bin Luo, Kuan-Hua Chao
  • Patent number: 9042820
    Abstract: An optical receiver circuit is disclosed in which a number of electrical signals are processed to extract data encoded therein. The electrical signals may be compared during the process to selectively remove one or more waveforms from one or more corresponding electrical signals. Various data signals, each including one or more waveforms, may then be processed to extract the encoded data. The optical receiver circuit reduces, or eliminates, electrical offsets which may be present in one or more of the electrical signals to reduce corresponding errors in the encoded data signals.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: May 26, 2015
    Assignee: Infinera Corporation
    Inventors: Huan-Shang Tsai, Jeffrey T. Rahn
  • Patent number: 9042741
    Abstract: Described herein are systems and methods for accurately estimating and removing a carrier frequency offset. One exemplary embodiment relates to a system comprising a frequency offset detection circuit detecting a carrier frequency offset in an optical signal, and a frequency testing circuit calculating an estimated frequency offset value of the carrier frequency offset, wherein the frequency testing circuit removes a carrier phase based on the estimated frequency offset value and recovers the optical signal. Another exemplary embodiment relates to a method comprising detecting a carrier frequency offset in an optical signal, calculating an estimated frequency offset value of the carrier frequency offset, removing a carrier phase based on the estimated frequency offset value, and recovering the optical signal.
    Type: Grant
    Filed: March 15, 2011
    Date of Patent: May 26, 2015
    Assignee: AT&T INTELLECTUAL PROPERTY I, L.P.
    Inventor: Xiang Zhou
  • Patent number: 9031420
    Abstract: An optical signal is converted into an electric signal by an O/E converter on the reception side, and converted into a digital signal by an analog/digital conversion unit. In a capture unit A at the input stage of the digital signal processing unit at the next stage, the constellation of a signal output from an analog/digital conversion unit is acquired for each polarization. According to the constellation information, the amplitude value of the electric signal input to the analog/digital conversion unit is corrected so that the value is optimum. Also, the capture unit B acquires the constellation on the signal after the demodulation by the digital signal processing. According to the constellation information, the amplitude of the I and Q signals and the skew between the I and Q signals are corrected.
    Type: Grant
    Filed: February 5, 2013
    Date of Patent: May 12, 2015
    Assignee: Fujitsu Limited
    Inventor: Yuichirou Sakamoto
  • Patent number: 9031415
    Abstract: An Ethernet adapter system may include a transmitter to insert a payload type identifier sequence in a generic frame procedure header to indicate that a network is a converged enhanced Ethernet network. The transmitter may insert idle sequences in a stream of data frames transmitted along a link. The system may include a receiver to recognize a condition and to force a loss of synchronization condition on the link that will be converted by the receiver into a loss of light condition. The receiver may scan the transmitted stream of data frames for invalid data frames and introduce a code into the stream of data frames whenever an invalid data frame is detected.
    Type: Grant
    Filed: December 8, 2012
    Date of Patent: May 12, 2015
    Assignee: International Business Machines Corporation
    Inventors: Casimer M. DeCusatis, Thomas A. Gregg, Rajaram B. Krishnamurthy
  • Patent number: 9031421
    Abstract: Provided is a method of measuring signal transmission time difference of a measuring device. The measuring device according to embodiments, by measuring a skew on two optical paths through signal delays of sufficient sizes for skew measurement on the optical paths, even a skew having a minute size can be measured within a measurable range.
    Type: Grant
    Filed: July 3, 2013
    Date of Patent: May 12, 2015
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Joong-Seon Choe, Chun Ju Youn, Jong-Hoi Kim, Duk Jun Kim, Yong-Hwan Kwon, Kwang-Seong Choi, Eun Soo Nam
  • Patent number: 9025971
    Abstract: An optical receiving circuit includes: a first non-feedback amplifier configured to convert a current signal, obtained from a light receiving element in response to an optical signal, into a first voltage signal; a second amplifier configured to convert an input current signal into a second voltage signal, the output signal not being directly fed back to an input side; a differential amplifier configured to perform differential amplification on the first voltage signal and the second voltage signal and to output an in positive signal and a negative signal obtained through the differential amplification; and an offset compensation circuit configured to input, on the basis of the in positive signal and the negative signal output from the differential amplifier, an offset current signal in accordance with an offset of a level of the in positive signal from a level of the negative signal to the second amplifier.
    Type: Grant
    Filed: November 27, 2013
    Date of Patent: May 5, 2015
    Assignee: Fujitsu Limited
    Inventor: Satoshi Ide
  • Patent number: 9025969
    Abstract: An optical signal receiver tracks local oscillator frequency offset (LOFO) and compensates for the phase distortion introduced in the received signals as a result of utilizing the local oscillator within a coherent detection scheme. This phase distortion is basically a constant phase rotation caused by the LOFO and implementation of the receiver using coherent detection and a digital interferometer instead of a conventional (yet complex) carrier phase estimation or recovery scheme. With an optical receiver implemented in this manner, the requirement of using a precise local oscillator laser with low frequency offset is less important.
    Type: Grant
    Filed: May 24, 2012
    Date of Patent: May 5, 2015
    Assignee: Futurewei Technologies, Inc.
    Inventors: Chuandong Li, Yuanjie Chen, Zhuhong Zhang, Yi Cai, Fei Zhu
  • Patent number: 9020366
    Abstract: Provided are a polarization multiplexing optical receiving device and a polarization multiplexing optical receiving method with which a mismatch of optical intensity between polarized signals accumulated in an optical transmission path of an optical receiving system can be compensated with high precision, and a high-quality polarized optical signal can be received.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: April 28, 2015
    Assignee: NEC Corporation
    Inventor: Takeshi Okamoto
  • Patent number: 9014574
    Abstract: In order to appropriately demultiplex the polarization multiplexed BPSK signal without using a training sequence and decreasing the resistance to a frequency offset, an optical receiver includes a coherent optical detection unit receiving an optical signal in which BPSK modulated carrier waves are polarization-multiplexed, performing coherent detection by mixing the received optical signal with local light, and outputting first electrical signals corresponding to the carrier waves; a butterfly FIR filter receiving the first electrical signals and extracting second electrical signals corresponding to each of the carrier waves from the first electrical signals; and a coefficient control unit for calculating a sum of respective phases of the second electrical signals output from the butterfly FIR filter, adaptively controlling tap coefficients of the butterfly FIR filter so that the calculated phase sum may become equal to 0 or ?, and outputting tap coefficients after being controlled to the butterfly FIR filter
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: April 21, 2015
    Assignee: NEC Corporation
    Inventors: Manabu Arikawa, Daisaku Ogasahara, Emmanuel Le Taillandier de Gabory, Kiyoshi Fukuchi
  • Patent number: 9014575
    Abstract: In a sampling clock synchronizing apparatus, an A/D converter converts an analog signal to a digital signal based on a sampling clock, and a processor compensates a band limitation due to spectral narrowing by filter characteristics of characteristics opposite to those of the spectral narrowing with respect to a signal produced from the A/D converter subjected to the spectral narrowing, and detects a phase shift in the sampling clock based on a signal after the compensation of the spectral narrowing and synchronizes sampling timing.
    Type: Grant
    Filed: January 6, 2012
    Date of Patent: April 21, 2015
    Assignee: Fujitsu Limited
    Inventors: Hisao Nakashima, Takeshi Hoshida
  • Patent number: 9002215
    Abstract: A coherent optical receiver measures a portion of a spectra of a multi-channel optical signal that includes at least one signal adjacent to a selected signal. The coherent optical receiver determines structure and bandwidth information for the measured portion of spectra, and determines one or more filter parameters for the selected signal based on the structure and bandwidth information of the at least one signal adjacent to the selected signal. The coherent optical receiver adjusts one or more active filter parameters of a carrier phase estimator in the optical coherent receiver to have values corresponding to the determined one or more filter parameters.
    Type: Grant
    Filed: July 11, 2013
    Date of Patent: April 7, 2015
    Assignee: Oclaro, Inc.
    Inventor: Sunil Kumar Singh Khatana
  • Patent number: 8989602
    Abstract: A digital coherent optical receiver includes a processor that is operative to separate electric signals obtained by converting an optical signal into a horizontal signal component and a vertical signal component; to generate a histogram of the horizontal signal component and the vertical signal component as outputs of the equalizing filter; and to determine a presence/absence of local convergence based on distribution of the histogram of the horizontal signal component and the histogram of the vertical signal component.
    Type: Grant
    Filed: October 27, 2011
    Date of Patent: March 24, 2015
    Assignee: Fujitsu Limited
    Inventors: Kosuke Komaki, Osamu Takeuchi
  • Patent number: 8977141
    Abstract: A parameter of an adaptive filter is optimized so that inter-symbol interference having an amount corresponding to an inserted fixed filter remains.
    Type: Grant
    Filed: February 7, 2012
    Date of Patent: March 10, 2015
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kengo Horikoshi, Etsushi Yamazaki, Takayuki Kobayashi, Eiji Yoshida, Yutaka Miyamoto
  • Patent number: 8977138
    Abstract: A technique is provided for configuring an optical receiver. A photo detector is connected to a load resistor, and the photo detector includes an internal capacitance. A current source is connected through a switching circuit to the load resistor and to the photo detector. The current source is configured to discharge the internal capacitance of the photo detector. The switching circuit is configured to connect the current source to the internal capacitance based on a previous data bit.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: March 10, 2015
    Assignee: International Business Machines Corporation
    Inventors: Jonathan E. Proesel, Alexander V. Rylyakov, Clint L. Schow, Yurii A. Vlasov