Patents by Inventor Lee Dardis

Lee Dardis 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).

  • Alignment of in-phase and quadrature data in quadrature phase shift keying optical transmitters
    Patent number: 8644420
    Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include streams of alternating ones and zeroes.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: February 4, 2014
    Assignee: Opnext Subsystems, Inc.
    Inventors: Sunil Kumar Singh Khatana, Lee Dardis
  • Mach-Zehnder Modulator Drive Level Optimization
    Publication number: 20140016172
    Abstract: A method for determining, by a modulator assembly, an optimal drive point for a Mach-Zehnder modulator (MZM). The modulator assembly applies an electrical modulation signal to the MZM to modulate an optical input signal and create a modulated optical output signal, the modulated optical output having a spectrum that includes a first and third harmonic. The modulator assembly measures the difference in magnitude between the first harmonic and the third harmonic as the amplitude of the electrical modulation signal is varied, and determines a value for the amplitude of the electrical modulation signal that corresponds to a maximum difference between the first harmonic and the third harmonic.
    Type: Application
    Filed: July 11, 2013
    Publication date: January 16, 2014
    Inventors: Sunil Kumar Singh Khatana, Lee Dardis
  • Alignment of In-phase and Quadrature Data in Quadrature Phase Shift Keying Optical Transmitters
    Publication number: 20120250792
    Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include streams of alternating ones and zeroes.
    Type: Application
    Filed: April 1, 2011
    Publication date: October 4, 2012
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Sunil Kumar Singh Khatana, Lee Dardis