Patents by Inventor Koon Whye Loh

Koon Whye Loh 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: 6922102
    Abstract: An amplifier includes a main amplifier circuit and at least one auxiliary amplifier circuit. Portions of an RF signal to be amplified are delivered to the main and auxiliary amplifiers. The auxiliary amplifier circuit is selectively operable to operate in combination with the main amplifier circuit, such as based on the level of the RF signal. At least one hybrid coupler circuit has input ports coupled with outputs of the main amplifier circuit and auxiliary amplifier circuit. The hybrid coupler circuit is operable to combine amplifier circuit output signals at a coupler first output port. A coupler second output port is terminated with one of an electrical short and an electrical open circuit.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: July 26, 2005
    Assignee: Andrew Corporation
    Inventors: Robert E. Myer, Koon Whye Loh, Loren Francis Root, Edward Vincent Louis
  • Publication number: 20040189380
    Abstract: An amplifier includes a main amplifier circuit and at least one auxiliary amplifier circuit. Portions of an RF signal to be amplified are delivered to the main and auxiliary amplifiers. The auxiliary amplifier circuit is selectively operable to operate in combination with the main amplifier circuit, such as based on the level of the RF signal. At least one hybrid coupler circuit has input ports coupled with outputs of the main amplifier circuit and auxiliary amplifier circuit. The hybrid coupler circuit is operable to combine amplifier circuit output signals at a coupler first output port. A coupler second output port is terminated with one of an electrical short and an electrical open circuit.
    Type: Application
    Filed: March 28, 2003
    Publication date: September 30, 2004
    Applicant: Andrew Corporation
    Inventors: Robert E. Myer, Koon Whye Loh, Loren Francis Root, Edward Vincent Louis
  • Patent number: 5646578
    Abstract: The present invention is directed to a wide dynamic range power amplifier having a power amplification circuit for increasing the power of an incoming signal to an output power suitable for transmitting the signal over a communication medium, and a feedback circuit coupled between the output and gain control input of the power amplification circuit for changing the output power to a new, desired output power.The feedback circuit may include a digital step attenuator, a power detector, a reference D.C. voltage, and a comparator. To change the output power, the digital step attenuates the output power sensed by the power detector, from a first attenuation level to a second attenuation level, by an amount corresponding to the desired change in output power. The power conversion circuit converts the output power at the second attenuation level to a D.C. voltage for comparison with the reference D.C. voltage which corresponds to the output power at the first attenuation level.
    Type: Grant
    Filed: July 30, 1996
    Date of Patent: July 8, 1997
    Assignee: Lucent Technologies Inc.
    Inventors: Koon Whye Loh, Yatish Swarup Pathak