Patents by Inventor Wan Jong Kim

Wan Jong Kim 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: 9225296
    Abstract: A system for time aligning widely frequency spaced signals includes a digital predistortion (DPD) processor and a power amplifier coupled to the DPD processor and operable to provide a transmit signal at a power amplifier output. The system also includes a feedback loop coupled to the power amplifier output. The feedback loop comprises an adaptive fractional delay filter, a delay estimator coupled to the adaptive fractional delay filter, and a DPD coefficient estimator coupled to the delay estimator.
    Type: Grant
    Filed: July 18, 2013
    Date of Patent: December 29, 2015
    Assignee: Dali Systems Co. Ltd.
    Inventor: Wan Jong Kim
  • Patent number: 9197259
    Abstract: A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.
    Type: Grant
    Filed: September 8, 2014
    Date of Patent: November 24, 2015
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
  • Patent number: 9184703
    Abstract: A power amplifier using N-way Doherty structure with adaptive bias supply power tracking for extending the efficiency region over the high peak-to-average power:ratio of the multiplexing modulated signals such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. In an embodiment, present invention uses a dual-feed distributed structure to an N-way Doherty amplifier to improve the isolation between at least one main amplifier and at least one peaking amplifier and, and also to improve both gain and efficiency performance at high output back-off power. Hybrid couplers can be used at either or both of the input and output. In at least some implementations, circuit space is also conserved due to the integration of amplification, power splitting and combining.
    Type: Grant
    Filed: November 22, 2013
    Date of Patent: November 10, 2015
    Assignee: Dali Systems Co. Ltd.
    Inventors: Kyoung Joon Cho, Wan Jong Kim, Shawn Patrick Stapleton
  • Publication number: 20150180519
    Abstract: A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.
    Type: Application
    Filed: November 24, 2014
    Publication date: June 25, 2015
    Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
  • Publication number: 20150171899
    Abstract: A high performance and cost effective method of RF-digital hybrid mode power amplifier systems with high linearity and high efficiency for multi-frequency band wideband communication system applications is disclosed. The present disclosure enables a power amplifier system to be field reconfigurable and support multiple operating frequency bands on the same PA system over a very wide bandwidth. In addition, the present invention supports multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels.
    Type: Application
    Filed: November 25, 2014
    Publication date: June 18, 2015
    Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton
  • Patent number: 9048797
    Abstract: A remote radio head unit (RRU) system is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier inside the RRU. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by a wideband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, embodiments of the present invention can compensate for the nonlinearities as well as memory effects of the power amplifier systems and also improve performance, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers, multi-frequency bands and multi-channels.
    Type: Grant
    Filed: July 18, 2014
    Date of Patent: June 2, 2015
    Assignee: DALI SYSTEMS CO. LTD.
    Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton, Ying Xiao
  • Publication number: 20150092830
    Abstract: An efficient baseband predistortion linearization method for reducing the spectral regrowth and compensating memory effects in wideband communication systems using effective multiplexing modulation technique such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. The present invention is based on the method of piecewise pre-equalized lookup table based predistortion, which is a cascade of a lookup table predistortion and piecewise pre-equalizers.
    Type: Application
    Filed: September 8, 2014
    Publication date: April 2, 2015
    Inventors: Wan-Jong Kim, Kyoung Joon Cho, Jong Heon Kim, Shawn Patrick Stapleton
  • Publication number: 20150080054
    Abstract: A remote radio head unit (RRU) system is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier inside the RRU. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by a wideband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, embodiments of the present invention can compensate for the nonlinearities as well as memory effects of the power amplifier systems and also improve performance, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers, multi-frequency bands and multi-channels.
    Type: Application
    Filed: July 18, 2014
    Publication date: March 19, 2015
    Applicant: DALI SYSTEMS CO. LTD.
    Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton, Ying Xiao
  • Publication number: 20150010110
    Abstract: A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels. As a result, the digital hybrid mode power amplifier system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems, where baseband I-Q signal information is not readily available.
    Type: Application
    Filed: July 21, 2014
    Publication date: January 8, 2015
    Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Ying Xiao
  • Publication number: 20140376661
    Abstract: A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.
    Type: Application
    Filed: September 8, 2014
    Publication date: December 25, 2014
    Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
  • Patent number: 8913689
    Abstract: A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.
    Type: Grant
    Filed: February 26, 2013
    Date of Patent: December 16, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
  • Patent number: 8903337
    Abstract: A high performance and cost effective method of RF-digital hybrid mode power amplifier systems with high linearity and high efficiency for multi-frequency band wideband communication system applications is disclosed. The present disclosure enables a power amplifier system to be field reconfigurable and support multiple operating frequency bands on the same PA system over a very wide bandwidth. In addition, the present invention supports multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels.
    Type: Grant
    Filed: May 15, 2013
    Date of Patent: December 2, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton
  • Publication number: 20140327481
    Abstract: A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by the narrowband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, the present invention could compensate the nonlinearities as well as memory effects of the power amplifier systems and also improve performances, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels.
    Type: Application
    Filed: May 7, 2014
    Publication date: November 6, 2014
    Applicant: DALI SYSTEMS CO., LTD.
    Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Jong Heon Kim, Dali Yang
  • Patent number: 8873674
    Abstract: A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.
    Type: Grant
    Filed: September 24, 2012
    Date of Patent: October 28, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
  • Patent number: 8855234
    Abstract: An efficient baseband predistortion linearization method for reducing the spectral regrowth and compensating memory effects in wideband communication systems using effective multiplexing modulation technique such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. The present invention is based on the method of piecewise pre-equalized lookup table based predistortion, which is a cascade of a lookup table predistortion and piecewise pre-equalizers.
    Type: Grant
    Filed: May 3, 2013
    Date of Patent: October 7, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan Jong Kim, Kyoung Joon Cho, Jong Heon Kim, Shawn Patrick Stapleton
  • Patent number: 8823152
    Abstract: In one embodiment, a semiconductor package (e.g., a QFP package) includes a leadframe sized and configured to increase the available number of exposed leads in the semiconductor package. More particularly, the semiconductor package includes a generally planar die pad defining multiple peripheral edge segments. In addition, the semiconductor package includes a plurality of leads. Some of these leads include exposed bottom surface portions that are provided in at least one row or ring, which at least partially circumvents the die pad, with other leads including portions that protrude from respective side surfaces of a package body of the semiconductor package. At least one semiconductor die is connected to the top surface of the die pad and is electrically connected to at least some of the leads.
    Type: Grant
    Filed: July 12, 2011
    Date of Patent: September 2, 2014
    Assignee: Amkor Technology, Inc.
    Inventors: Gi Jeong Kim, Wan Jong Kim
  • Patent number: 8824595
    Abstract: A remote radio head unit (RRU) system is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier inside the RRU. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by a wideband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, embodiments of the present invention can compensate for the nonlinearities as well as memory effects of the power amplifier systems and also improve performance, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers, multi-frequency bands and multi-channels.
    Type: Grant
    Filed: September 6, 2013
    Date of Patent: September 2, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton, Ying Xiao
  • Publication number: 20140241461
    Abstract: A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.
    Type: Application
    Filed: February 26, 2013
    Publication date: August 28, 2014
    Applicant: DALI SYSTEMS CO. LTD.
    Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
  • Patent number: 8811917
    Abstract: A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by the narrowband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, the present invention could compensate the nonlinearities as well as memory effects of the power amplifier systems and also improve performances, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels.
    Type: Grant
    Filed: April 23, 2008
    Date of Patent: August 19, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Jong Heon Kim, Dali Yang
  • Patent number: 8804870
    Abstract: A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels. As a result, the digital hybrid mode power amplifier system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems, where baseband I-Q signal information is not readily available.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: August 12, 2014
    Assignee: Dali Systems Co. Ltd.
    Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Ying Xiao