Patents by Inventor Xiangjun Zhao
Xiangjun Zhao 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).
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Publication number: 20240381053Abstract: An ultra-wideband (UWB) ranging method comprises determining, by a first device, that the first device is within proximity of a second device. Responsive to the determination, the first device negotiates a value to use as a UWB session key for securing UWB communications with the second device. The negotiation occurs via a communication protocol different from a UWB communication protocol. The first device controls a UWB subsystem therein to encrypt information communicated via the UWB subsystem based on the negotiated value of the UWB session key instead of a default value for the UWB session key that is specified in the UWB communication protocol. The information facilitates determining the distance between the first device and the second device.Type: ApplicationFiled: August 17, 2021Publication date: November 14, 2024Inventors: Liping Liu, Darren David Krahn, Xiangjun Zhao, Ning Zhang, Jian Wang, Roshan Pius
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Patent number: 12009635Abstract: A method (600) for tuning a tunable laser (310) includes delivering a bias current (IDBR) to an anode of a distributed Bragg reflector (DBR) section diode (D2) disposed on a shared substrate of the tunable laser and receiving a burst mode signal (440) indicative of a burst-on state or a burst-off state. When the burst mode signal is indicative of the burst-off state, the method includes offsetting the bias current at the anode of the DBR section diode by one of sourcing a push current with the bias current to the anode of the DBR section diode or sinking a pull current away from the bias current at the anode of the DBR section diode. When the burst mode signal is indicative of the burst-on state, the method also includes ceasing any offsetting of the bias current at the anode of the DBR section diode.Type: GrantFiled: May 7, 2019Date of Patent: June 11, 2024Assignee: Google LLCInventors: Tao Zhang, Cedric Fung Lam, Xiangjun Zhao, Shuang Yin, Liang Du, Changhong Joy Jiang, Adam Edwin Taylor Ward Barratt, Claudio Desanti, Muthu Nagarajan
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Patent number: 11901696Abstract: A method (700) of biasing a tunable laser (310) during burst-on and burst-off states includes receiving a burst mode signal (514) indicative of the burst-on state or the burst-off state and when the burst mode signal is indicative of the burst-on state: delivering a first bias current (IGAIN) to an anode of a gain-section diode (590a) disposed on a shared substrate of the tunable laser; and delivering a second bias current (IPH) to an anode of phase-section diode (590b) disposed on the shared substrate. The second bias current is less than the first bias current. When the burst mode signal transitions to be indicative of the burst-off state, the method also includes delivering the first bias current to the anode of the gain-section diode; and delivering the second bias current to the anode of the phase-section diode wherein the first bias current is less than the second bias current.Type: GrantFiled: May 7, 2019Date of Patent: February 13, 2024Assignee: Google LLCInventors: Tao Zhang, Cedric Fung Lam, Shuang Yin, Xiangjun Zhao, Liang Du, Changhong Joy Jiang, Adam Edwin Taylor Barratt, Claudio Desanti, Muthu Nagarajan
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Patent number: 11600965Abstract: A method (900) includes a gain current (IGAIN) to an anode of a gain-section diode (D0) disposed on a shared substrate of a tunable laser (310), delivering a modulation signal to an anode of an Electro-absorption section diode (D2) disposed on the shared substrate of the tunable laser, and receiving a burst mode signal (330) indicative of a burst-on state or a burst-off state. When the burst mode signal is indicative of the burst-off state, the method includes sinking a sink current (ISINK) away from the gain current at the anode of the gain-section diode. When the burst mode signal transitions to be indicative of the burst-on state from the burst-off state, the method includes ceasing the sinking of the sink current away from the gain current and delivering an overshoot current (IOVER) to the anode of the gain-section diode.Type: GrantFiled: May 6, 2019Date of Patent: March 7, 2023Assignee: Google LLCInventors: Tao Zhang, Cedric Fung Lam, Shuang Yin, Xiangjun Zhao, Liang Du, Changhong Joy Jiang, Adam Edwin Taylor Barratt, Claudio Desanti, Muthu Nagarajan
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Patent number: 11594856Abstract: A method (900) includes delivering a first bias current (IGAIN) to an anode of gain-section diode (590a) and delivering a second bias current (IPH) to an anode of a phase-section diode (590b). The method also includes receiving a burst mode signal (514) indicative of a burst-on state or a burst-on state, and sinking a first sink current (ISINK) away from the first bias current when the burst mode signal is indicative of the burst-off state. When the burst mode signal transitions to be indicative of the burst-on state from the burst-off state, the method also includes sinking a second sink current away from the second bias current at the anode of the phase-section diode and ceasing the sinking of the first sink current away from the first bias current at the anode of the gain section diode.Type: GrantFiled: May 7, 2019Date of Patent: February 28, 2023Assignee: Google LLCInventors: Tao Zhang, Cedric Fung Lam, Shuang Yin, Xiangjun Zhao, Liang Du, Changhong Joy Jiang, Adam Edwin Taylor Barratt, Claudio Desanti, Muthu Nagarajan
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Publication number: 20210203130Abstract: A method (900) includes delivering a first bias current (IGAIN) to an anode of a gain-section diode (590a) and delivering a second bias current (IPH) to an anode of a phase-section diode (590b). The method also includes receiving a burst mode signal (514) indicative of a burst-on state or a burst-on state, and sinking a first sink current (ISINK) away from the first bias current when the burst mode signal is indicative of the burst-off state. When the burst mode signal transitions to be indicative of the burst-on state from the burst-off state, the method also includes sinking a second sink current away from the second bias current at the anode of the phase-section diode and ceasing the sinking of the first sink current away from the first bias current at the anode of the gain section diode.Type: ApplicationFiled: May 7, 2019Publication date: July 1, 2021Applicant: Google LLCInventors: Tao Zhang, Cedric Fung Lam, Shuang Yin, Xiangjun Zhao, Liang Du, Changhong Joy Jiang, Adam Edwin Taylor Barratt, Claudio Desanti, Muthu Nagarajan
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Publication number: 20210203129Abstract: A method (900) includes a gain current (IGAIN) to an anode of a gain-section diode (D0) disposed on a shared substrate of a tunable laser (310), delivering a modulation signal to an anode of an Electro-absorption section diode (D2) disposed on the shared substrate of the tunable laser, and receiving a burst mode signal (330) indicative of a burst-on state or a burst-off state. When the burst mode signal is indicative of the burst-off state, the method includes sinking a sink current (ISINK) away from the gain current at the anode of the gain-section diode. When the burst mode signal transitions to be indicative of the burst-on state from the burst-off state, the method includes ceasing the sinking of the sink current away from the gain current and delivering an overshoot current (IOVER) to the anode of the gain-section diode.Type: ApplicationFiled: May 6, 2019Publication date: July 1, 2021Applicant: Google LLCInventors: Tao Zhang, Cedric Fung Lam, Shuang Yin, Xiangjun Zhao, Liang Du, Changhong Joy Jiang, Adam Edwin Taylor Barratt, Claudio Desanti, Muthu Nagarajan
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Publication number: 20210167577Abstract: A method (600) for tuning a tunable laser (310) includes delivering a bias current (IDBR) to an anode of a distributed Bragg reflector (DBR) section diode (D2) disposed on a shared substrate of the tunable laser and receiving a burst mode signal (440) indicative of a burst-on state or a burst-off state. When the burst mode signal is indicative of the burst-off state, the method includes offsetting the bias current at the anode of the DBR section diode by one of sourcing a push current with the bias current to the anode of the DBR section diode or sinking a pull current away from the bias current at the anode of the DBR section diode. When the burst mode signal is indicative of the burst-on state, the method also includes ceasing any offsetting of the bias current at the anode of the DBR section diode.Type: ApplicationFiled: May 7, 2019Publication date: June 3, 2021Applicant: Google LLCInventors: Tao Zhang, Cedric Fung Lam, Xiangjun Zhao, Shuang Yin, Liang Du, Changhong Joy Jiang, Adam Edwin Taylor Barratt, Claudio Desanti, Muthu Nagarajan
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Publication number: 20210151952Abstract: A method (700) of biasing a tunable laser (310) during burst-on and burst-off states includes receiving a burst mode signal (514) indicative of the burst-on state or the burst-off state and when the burst mode signal is indicative of the burst-on state: delivering a first bias current (IGAIN) to an anode of a gain-section diode (590a) disposed on a shared substrate of the tunable laser; and delivering a second bias current (IPH) to an anode of phase-section diode (590b) disposed on the shared substrate. The second bias current is less than the first bias current. When the burst mode signal transitions to be indicative of the burst-off state, the method also includes delivering the first bias current to the anode of the gain-section diode; and delivering the second bias current to the anode of the phase-section diode wherein the first bias current is less than the second bias current.Type: ApplicationFiled: May 7, 2019Publication date: May 20, 2021Applicant: Google LLCInventors: Tao Zhang, Cedric Fung Lam, Shuang Yin, Xiangjun Zhao, Liang Du, Changhong Joy Jiang, Adam Edwin Taylor Barratt, Claudio Desanti, Muthu Nagarajan
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Patent number: 10992387Abstract: A method of combining optical signals from a plurality of optical fibers into a single optical signal includes receiving, at corresponding optical-signal receivers optically coupled to corresponding trunk fibers, respective optical signals. The method further includes determining, by the corresponding optical-signal receivers, when each respective optical signal is received. When the respective optical signal is received, the method includes performing the following steps: converting, by the corresponding optical-signal receiver, the respective optical signal to a corresponding electrical signal; transmitting, by the corresponding optical-signal receiver, the corresponding electrical signal to a corresponding input channel of an electrical-multiplexing device; and configuring the electrical-multiplexing device to select the corresponding input channel.Type: GrantFiled: September 12, 2019Date of Patent: April 27, 2021Assignee: Google LLCInventors: Cedric Fung Lam, Xiangjun Zhao, Shuang Yin, Muthu Nagarajan, Tao Zhang, Liang Du, Adam Edwin Taylor Barratt, Changhong Joy Jiang, Claudio Desanti
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Publication number: 20210083770Abstract: A method of combining optical signals from a plurality of optical fibers into a single optical signal includes receiving, at corresponding optical-signal receivers optically coupled to corresponding trunk fibers, respective optical signals. The method further includes determining, by the corresponding optical-signal receivers, when each respective optical signal is received. When the respective optical signal is received, the method includes performing the following steps: converting, by the corresponding optical-signal receiver, the respective optical signal to a corresponding electrical signal; transmitting, by the corresponding optical-signal receiver, the corresponding electrical signal to a corresponding input channel of an electrical-multiplexing device; and configuring the electrical-multiplexing device to select the corresponding input channel.Type: ApplicationFiled: September 12, 2019Publication date: March 18, 2021Applicant: Google LLCInventors: Cedric Fung Lam, Xiangjun Zhao, Shuang Yin, Muthu Nagarajan, Tao Zhang, Liang Du, Adam Edwin Taylor Barratt, Changhong Joy Jiang, Claudio Desanti
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Publication number: 20210015966Abstract: The disclosure provides a preparation method for a novel biocompatible antibacterial bacterial cellulose Fmoc-F hydrogel, belonging to the technical field of biomedical gels. The preparation method is characterized by comprising the following steps of (1) preparing a bacterial cellulose (BC) homogenate, (2) mixing the bacterial cellulose with an Fmoc-F solution, and preparing the bacterial cellulose/Fmoc-F antibacterial hydrogel by means of in-situ chemical crosslinking. The preparation method has the advantages of rapid gelling reaction, simple reaction system, high gel plasticity and the like. Because of the bacterial cellulose, the antibacterial hydrogel prepared in the disclosure has high mechanical strength. Meanwhile, compared with traditional micro-molecular antibacterial materials, the bacterial cellulose/Fmoc-F antibacterial hydrogels prepared in the disclosure have broad-spectrum antibacterial effects and good biocompatibility.Type: ApplicationFiled: September 29, 2020Publication date: January 21, 2021Inventors: Cheng ZHONG, Xiangjun Zhao, Yanwen Zhang, Fazli WAHID, Yanyan Xie, Shiru Jia
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Patent number: 10666379Abstract: A method of establishing communication between an optical line terminal and an optical network unit within an optical access network includes receiving a signal indication from an optical transceiver of an optical line terminal. The signal indication includes: (i) a loss-of-signal indication indicating non-receipt of an upstream optical signal from the optical network unit; or (ii) a signal-received indication indicating receipt of the upstream optical signal from the optical network unit. The method includes determining whether the signal indication includes the loss-of-signal indication. When the signal indication includes the loss-of-signal indication, the method includes instructing the optical transceiver to cease signal transmission from the optical transceiver to the optical network unit.Type: GrantFiled: March 13, 2019Date of Patent: May 26, 2020Assignee: Google LLCInventors: Xiangjun Zhao, Cedric Fung Lam, Shuang Yin, Changhong Joy Jiang, Ke Dong
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Patent number: 10651946Abstract: A method for in-field calibration of a laser transmitter includes receiving, at an optical network unit (ONU), a downstream connection from an optical line terminal (OLT) where the ONU includes a Distributed Bragg Reflector (DBR) laser. The method further includes attempting to establish an upstream connection between the ONU and the OLT. When the ONU establishes the upstream connection to the OLT, the method also includes receiving, at the ONU, a message to initiate calibration of the ONU where the message is generated to indicate that the DBR laser is operating outside an operational state. The method further includes tuning, by the ONU, the DBR laser to the operational state by adjusting an injection current for the DBR laser.Type: GrantFiled: May 30, 2019Date of Patent: May 12, 2020Assignee: Google LLCInventors: Xiangjun Zhao, Satrukaan Sivagnanasuntharam, Shuang Yin, Cedric Fung Lam, Liang Du
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Publication number: 20190393958Abstract: A remote node includes a first node input, a second node input, and an optical switch. The optical switch includes a first switch input optically coupled to the first node input, a second switch input optically coupled to the second node input, a first switch output switchably coupled to the first switch input or the second switch input, and a second switch output switchably coupled to the first switch input or the second switch input. The remote node includes a photodiode optically coupled to the second switch output, and a capacitor electrically coupled to the photodiode and the optical switch. When the first switch input is switchably coupled to the first switch output, the second switch input is switchably coupled to the second switch output. Light received by the second switch input passes out the second switch output to the photodiode. The photodiode charges the capacitor to a threshold charge.Type: ApplicationFiled: August 28, 2019Publication date: December 26, 2019Applicant: Google LLCInventors: Liang Du, Yut Loy Chan, Xiangjun Zhao, Changhong Joy Jiang, Cedric Fung Lam, Daoyi Wang, Tao Zhang
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Patent number: 10516479Abstract: A remote node includes a first node input, a second node input, and an optical switch. The optical switch includes a first switch input optically coupled to the first node input, a second switch input optically coupled to the second node input, a first switch output switchably coupled to the first switch input or the second switch input, and a second switch output switchably coupled to the first switch input or the second switch input. The remote node includes a photodiode optically coupled to the second switch output, and a capacitor electrically coupled to the photodiode and the optical switch. When the first switch input is switchably coupled to the first switch output, the second switch input is switchably coupled to the second switch output. Light received by the second switch input passes out the second switch output to the photodiode. The photodiode charges the capacitor to a threshold charge.Type: GrantFiled: August 28, 2019Date of Patent: December 24, 2019Assignee: Google LLCInventors: Liang Du, Yut Loy Chan, Xiangjun Zhao, Changhong Joy Jiang, Cedric Fung Lam, Daoyi Wang, Tao Zhang
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Patent number: 10461498Abstract: A method for biasing a tunable laser during burst-on and burst-off states through a common-cathode laser driving circuit includes delivering a bias current to an anode of a gain-section diode having a shared substrate with the laser, and receiving a burst mode signal indicative of a burst-on state or a burst-off state. When the burst mode signal is indicative of the burst-off state, the method includes sinking a sink current away from the anode of the gain-section diode. The sink current is less than the bias current delivered to the anode of the gain-section diode. When the burst mode signal transitions to be indicative of the burst-on state from the burst-off state, the method includes ceasing the sinking of the sink current away from the anode of the gain-section diode, and delivering an overshoot current to the anode of the gain-section diode to accelerate heating of the gain-section diode.Type: GrantFiled: October 1, 2018Date of Patent: October 29, 2019Assignee: Google LLCInventors: Tao Zhang, Liang Du, Xiangjun Zhao, Changhong Joy Jiang, Cedric Fung Lam, Shuang Yin, Adam Edwin Taylor Barratt
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Patent number: 10439722Abstract: A carrier office includes an optical line terminal, a first transmit-erbium-doped fiber amplifier (EDFA), and a second transmit-EDFA. The OLT is configured to transmit first and second optical signals. The first transmit-EDFA is optically coupled to the OLT and a first feeder fiber, and the first feeder fiber is optically coupled to a first remote node (RN). The first transmit-EDFA is operable between a respective enabled state and a respective disabled state. The second transmit-EDFA is optically coupled to the OLT and a second feeder fiber, and the second feeder fiber is optically coupled to a second RN. The second transmit-EDFA is operable between a respective enabled state and a respective disabled state.Type: GrantFiled: July 17, 2018Date of Patent: October 8, 2019Assignee: Google LLCInventors: Liang Du, Yut Loy Chan, Xiangjun Zhao, Changhong Joy Jiang, Cedric Fung Lam, Daoyi Wang, Tao Zhang
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Publication number: 20190215093Abstract: A method of establishing communication between an optical line terminal and an optical network unit within an optical access network includes receiving a signal indication from an optical transceiver of an optical line terminal. The signal indication includes: (i) a loss-of-signal indication indicating non-receipt of an upstream optical signal from the optical network unit; or (ii) a signal-received indication indicating receipt of the upstream optical signal from the optical network unit. The method includes determining whether the signal indication includes the loss-of-signal indication. When the signal indication includes the loss-of-signal indication, the method includes instructing the optical transceiver to cease signal transmission from the optical transceiver to the optical network unit.Type: ApplicationFiled: March 13, 2019Publication date: July 11, 2019Applicant: Google LLCInventors: Xiangjun Zhao, Cedric Fung Lam, Shuang Yin, Changhong Joy Jiang, Ke Dong
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Patent number: 10243687Abstract: A method of establishing communication between an optical line terminal and an optical network unit within an optical access network includes receiving a signal indication from an optical transceiver of an optical line terminal. The signal indication includes: (i) a loss-of-signal indication indicating non-receipt of an upstream optical signal from the optical network unit; or (ii) a signal-received indication indicating receipt of the upstream optical signal from the optical network unit. The method includes determining whether the signal indication includes the loss-of-signal indication. When the signal indication includes the loss-of-signal indication, the method includes instructing the optical transceiver to cease signal transmission from the optical transceiver to the optical network unit.Type: GrantFiled: November 17, 2016Date of Patent: March 26, 2019Assignee: Google LLCInventors: Xiangjun Zhao, Cedric Fung Lam, Shuang Yin, Changhong Joy Jiang, Ke Dong