Patents by Inventor Sang Ho Kam

Sang Ho Kam 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: 8466746
    Abstract: A three-stage GaN HEMT Doherty power amplifier for high frequency applications includes: a carrier amplifier; first and second peaking amplifier; a 10-dB power divider configured to divide an input signal to the carrier amplifier and the first and second peaking amplifiers; a first path for controlling input power of the carrier amplifier; and a second path for maintaining an efficiency of 40% or more in an output range of 40 dBm to 50 dBm.
    Type: Grant
    Filed: January 6, 2012
    Date of Patent: June 18, 2013
    Assignee: Postech Academy-Industry Foundation
    Inventors: Yoon Ha Jeong, Mun Woo Lee, Sang Ho Kam
  • Patent number: 8400216
    Abstract: Disclosed is a 3-way Doherty power amplifier using a driving amplifier in which driving amplifiers are connected to the front stages of a carrier amplifier and a peaking amplifier, respectively, so as to obtain a high gain and a high efficiency. To this end, the Doherty power amplifier includes: a hybrid power distributor for distributing an input signal into first and second path units; and a driving amplifier for receiving a signal outputted from the hybrid power distributor and controlling the driving of a carrier amplifier, a first peaking amplifier, and a second peaking amplifier, wherein: the carrier amplifier, the first peaking amplifier, and the second peaking amplifier are connected to a rear stage of the driving amplifier, respectively; the first path unit generates a high efficiency at a low input power; and the second path unit maintains a high efficiency and gain in a high output range.
    Type: Grant
    Filed: November 1, 2011
    Date of Patent: March 19, 2013
    Assignee: Postech Academy-Industry Foundation
    Inventors: Yoon Ha Jeong, Sang Ho Kam, Yong Sub Lee, Mun Woo Lee
  • Publication number: 20120218044
    Abstract: A three-stage GaN HEMT Doherty power amplifier for high frequency applications includes: a carrier amplifier; first and second peaking amplifier; a 10-dB power divider configured to divide an input signal to the carrier amplifier and the first and second peaking amplifiers; a first path for controlling input power of the carrier amplifier; and a second path for maintaining an efficiency of 40% or more in an output range of 40 dBm to 50 dBm.
    Type: Application
    Filed: January 6, 2012
    Publication date: August 30, 2012
    Applicant: POSTECH ACADEMY- INDUSTRY FOUNDATION
    Inventors: Yoon Ha JEONG, Mun Woo LEE, Sang Ho KAM
  • Publication number: 20120112833
    Abstract: Disclosed is a 3-way Doherty power amplifier using a driving amplifier in which driving amplifiers are connected to the front stages of a carrier amplifier and a peaking amplifier, respectively, so as to obtain a high gain and a high efficiency. To this end, the Doherty power amplifier includes: a hybrid power distributor for distributing an input signal into first and second path units; and a driving amplifier for receiving a signal outputted from the hybrid power distributor and controlling the driving of a carrier amplifier, a first peaking amplifier, and a second peaking amplifier, wherein: the carrier amplifier, the first peaking amplifier, and the second peaking amplifier are connected to a rear stage of the driving amplifier, respectively; the first path unit generates a high efficiency at a low input power; and the second path unit maintains a high efficiency and gain in a high output range.
    Type: Application
    Filed: November 1, 2011
    Publication date: May 10, 2012
    Applicant: POSTECH ACADEMY- INDUSTRY FOUNDATION
    Inventors: Yoon- Ha JEONG, Sang- Ho KAM, Yong- Sub LEE, Mun- Woo LEE