Patents by Inventor Tony Shuo-Chun Kao

Tony Shuo-Chun Kao 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: 10355655
    Abstract: A TIA circuit is provided that utilizes current steering to adjust the gain of a TIA of the TIA circuit. As the optical input power of the optoelectronic (OE) detector that is coupled to the input of the TIA increases, the gain of the TIA is decreased via current steering, and as the optical input power of the OE detector decreases, the gain of the TIA is increased via current steering. Utilizing current steering to adjust the gain of the TIA allows the TIA circuit to have a configuration that has reduced power consumption compared to TIA circuits that use shunt feedback TIAs. In addition the TIA circuit configuration provides reduced peaking, improved linearization and high bandwidth.
    Type: Grant
    Filed: June 29, 2017
    Date of Patent: July 16, 2019
    Assignee: Avago Technologies International Sales Pte. Limited
    Inventors: Chakravartula Nallani, Georgios Asmanis, Faouzi Chaahoub, Alfred Sargezisardrud, Tony Shuo-Chun Kao
  • Publication number: 20190020320
    Abstract: A TIA circuit is provided that utilizes current steering to adjust the gain of a TIA of the TIA circuit. As the optical input power of the optoelectronic (OE) detector that is coupled to the input of the TIA increases, the gain of the TIA is decreased via current steering, and as the optical input power of the OE detector decreases, the gain of the TIA is increased via current steering. Utilizing current steering to adjust the gain of the TIA allows the TIA circuit to have a configuration that has reduced power consumption compared to TIA circuits that use shunt feedback TIAs. In addition the TIA circuit configuration provides reduced peaking, improved linearization and high bandwidth.
    Type: Application
    Filed: June 29, 2017
    Publication date: January 17, 2019
    Inventors: Chakravartula Nallani, Georgios Asmanis, Faouzi Chaahoub, Alfred Sargezisardrud, Tony Shuo-Chun Kao
  • Patent number: 9153936
    Abstract: An optical transmitter is disclosed. In accordance with some embodiments of the present disclosure, an optical transmitter may comprise a vertical-cavity surface-emitting laser (VCSEL) and a VCSEL driver. The VCSEL driver may comprise an input stage configured to receive a voltage signal and a low-impedance output stage comprising an input coupled to the input stage and a low-impedance output coupled to the VCSEL and configured to provide a modulated output current to the VCSEL.
    Type: Grant
    Filed: June 20, 2013
    Date of Patent: October 6, 2015
    Assignee: Fujitsu Limited
    Inventors: Tony Shuo-Chun Kao, Nikola Nedovic
  • Publication number: 20140376582
    Abstract: An optical transmitter is disclosed. In accordance with some embodiments of the present disclosure, an optical transmitter may comprise a vertical-cavity surface-emitting laser (VCSEL) and a VCSEL driver. The VCSEL driver may comprise an input stage configured to receive a voltage signal and a low-impedance output stage comprising an input coupled to the input stage and a low-impedance output coupled to the VCSEL and configured to provide a modulated output current to the VCSEL.
    Type: Application
    Filed: June 20, 2013
    Publication date: December 25, 2014
    Inventors: Tony Shuo-Chun Kao, Nikola Nedovic
  • Patent number: 8861560
    Abstract: In one embodiment, a driver circuit of a vertical-cavity surface-emitting laser (VCSEL) includes bias current sources, modulation current sources, and a switch component connected to the bias current sources at a first node and to the modulation current sources at second nodes; the switch component is configured to modulate a current from the bias and modulation current sources based on an input signal to the switch component; and the switch component is also configured to provide the modulated current to the VCSEL through a folded cascode transistor.
    Type: Grant
    Filed: November 6, 2012
    Date of Patent: October 14, 2014
    Assignee: Fujitsu Limited
    Inventors: Nikola Nedovic, Tony Shuo-Chun Kao
  • Patent number: 8787776
    Abstract: An optical receiver includes a photodetector for detecting incoming optical data signals and an amplifier for providing signal gain and current to voltage conversion. The detection signal generated by the photodetector may include a distortion component caused by an operating characteristic of the photodetector. A signal compensating circuit may reconstruct the received optical data signal by effectively canceling the distortion component. For this purpose, the signal compensating circuit may include a decision feedback equalizer implemented using at least one feedback filter matched to the operating characteristic of the photodetector causing the signal distortion so as to reproduce the distortion component for cancellation. Use of a control module may also configure the optical receiver in real time to account for other operating and environmental conditions of the optical receiver.
    Type: Grant
    Filed: June 3, 2011
    Date of Patent: July 22, 2014
    Assignee: The Governing Council of the University of Toronto
    Inventors: Anthony Chan Carusone, Tony Shuo-Chun Kao, Hemesh Yasotharan
  • Publication number: 20140126595
    Abstract: In one embodiment, a driver circuit of a vertical-cavity surface-emitting laser (VCSEL) includes bias current sources, modulation current sources, and a switch component connected to the bias current sources at a first node and to the modulation current sources at second nodes; the switch component is configured to modulate a current from the bias and modulation current sources based on an input signal to the switch component; and the switch component is also configured to provide the modulated current to the VCSEL through a folded cascode transistor.
    Type: Application
    Filed: November 6, 2012
    Publication date: May 8, 2014
    Inventors: Nikola Nedovic, Tony Shuo-Chun Kao
  • Publication number: 20120141122
    Abstract: An optical receiver includes a photodetector for detecting incoming optical data signals and an amplifier for providing signal gain and current to voltage conversion. The detection signal generated by the photodetector may include a distortion component caused by an operating characteristic of the photodetector. A signal compensating circuit may reconstruct the received optical data signal by effectively canceling the distortion component. For this purpose, the signal compensating circuit may include a decision feedback equalizer implemented using at least one feedback filter matched to the operating characteristic of the photodetector causing the signal distortion so as to reproduce the distortion component for cancellation. Use of a control module may also configure the optical receiver in real time to account for other operating and environmental conditions of the optical receiver.
    Type: Application
    Filed: June 3, 2011
    Publication date: June 7, 2012
    Inventors: Anthony Chan Carusone, Tony Shuo-Chun Kao, Hemesh Yasotharan