Patents by Inventor William B. Hwang

William B. Hwang 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: 5708573
    Abstract: A DC to DC converter including a resonant switching circuit (13, 51 , 115, 151, 125, 153); an impedance matching circuit (53) responsive to the resonant switching circuit; a rectifier circuit (55) responsive to the impedance matching circuit; an output filter circuit (57) responsive to rectifier circuit for providing a filtered DC to DC converter voltage output; and a varactor diode circuit (27, 29, 31, 61) responsive to the filtered DC to DC converter voltage output for controlling the impedance matching circuit such that the filtered DC to DC converter output voltage is substantially constant.
    Type: Grant
    Filed: February 1, 1996
    Date of Patent: January 13, 1998
    Assignee: Hughes Electronics
    Inventors: David M. Lusher, Wilbur E. Hong, William B. Hwang
  • Patent number: 5703771
    Abstract: A VHF inverter including an inverter circuit (100) for providing an inverter output; a constant magnitude, variable phase impedance transforming circuit (54, 154) responsive the inverter; and a load circuit (55, 155) responsive to the impedance transforming circuit.
    Type: Grant
    Filed: July 19, 1996
    Date of Patent: December 30, 1997
    Assignee: Hughes Electronics
    Inventors: Wilbur E. Wong, David M. Lusher, William B. Hwang
  • Patent number: 5673188
    Abstract: A DC to AC inverter that includes a first capacitor (11) and a first inductor (13) connected in series between a positive voltage supply node and a central node; a first active switch switching (15) connected across the first capacitor and driven with a first periodic drive signal of a predetermined frequency; a second capacitor (21) and a second inductor (23) connected in series between a negative voltage supply node and the central node; a second active switch (25) connected across the second capacitor and being driven with a second periodic signal of said predetermined frequency and being out of phase by 180 degrees relative to the first periodic drive signal; a bandpass filter (31, 33) connected between the central node and an output node; and a load (47) connected between the output node and ground.
    Type: Grant
    Filed: March 25, 1996
    Date of Patent: September 30, 1997
    Assignee: Hughes Electronic
    Inventors: David M. Lusher, Wilbur E. Hong, William B. Hwang
  • Patent number: 5668715
    Abstract: VHF DC to AC inverters which include switching circuitry (13, 115, 125) and multiple resonant waveshaping networks (C11, L11, C12; C21, L21, C22; C111, L111; C221, L221; C331, L331; C441, L441) connected between the switching circuitry and respective load circuits (33, 43, 133, 143).
    Type: Grant
    Filed: June 27, 1996
    Date of Patent: September 16, 1997
    Assignee: Hughes Electronics
    Inventors: Wilbur E. Hong, David M. Lusher, William B. Hwang
  • Patent number: 5610569
    Abstract: A co-fired inductor structure that includes a plurality of planar co-fired ceramic dielectric insulating layers (13); a plurality of elongated conductive strips (11-1-11-4, 12-1-12-4, 21-1-21-3, 22-1-22-3) arranged in four groups of parallel elongated conductive strips each group disposed on a respective dielectric insulating layer; and a plurality of via columns (101, 102, 103, 104) for interconnecting the ends of the elongated conductive strips such that the elongated conductive strips and the via columns form a winding.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: March 11, 1997
    Assignee: Hughes Electronics
    Inventors: William B. Hwang, David M. Lusher
  • Patent number: 5410276
    Abstract: Circuits for modulating an RF input signal applied to an RF high power amplifier to produce a modulated RF output signal. The present invention employs a VHF power supply or converter with a modulation control circuit that enables the power supply to be pulsed at frequencies commensurate with a radar in which it is employed, for example. Modulation of the high power amplifier is accomplished by applying a pulsed voltage output signal to a DC bias input of the high power amplifier. More particularly, the modulation control circuit receives a logic control signal, generates a pulse control signal in response thereto, and modulates a DC input signal processed by the converter. The VHF converter receives and modulates the DC input signal in response to the pulse control signal to cause the pulsed voltage output signal from the converter to pulse at a rate and duty cycle determined by the logic control signal. The output signal modulates the RF input signal amplified by the RF high power amplifier.
    Type: Grant
    Filed: December 28, 1993
    Date of Patent: April 25, 1995
    Assignee: Hughes Aircraft Company
    Inventors: William B. Hwang, Michael Brand, Ronnie B. Chan, Robert S. Boiles