Patents by Inventor Kyoung Joon Cho
Kyoung Joon Cho 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).
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Publication number: 20160173040Abstract: 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: ApplicationFiled: October 16, 2015Publication date: June 16, 2016Inventors: Kyoung Joon Cho, Wan Jong Kim, Shawn Patrick Stapleton
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Patent number: 9246731Abstract: 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: GrantFiled: September 8, 2014Date of Patent: January 26, 2016Assignee: Dali Systems Co. Ltd.Inventors: Wan-Jong Kim, Kyoung Joon Cho, Jong Heon Kim, Shawn Patrick Stapleton
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Publication number: 20150381217Abstract: 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: ApplicationFiled: May 4, 2015Publication date: December 31, 2015Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton, Ying Xiao
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Patent number: 9184703Abstract: 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: GrantFiled: November 22, 2013Date of Patent: November 10, 2015Assignee: Dali Systems Co. Ltd.Inventors: Kyoung Joon Cho, Wan Jong Kim, Shawn Patrick Stapleton
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Publication number: 20150171899Abstract: 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: ApplicationFiled: November 25, 2014Publication date: June 18, 2015Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton
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Patent number: 9048797Abstract: 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: GrantFiled: July 18, 2014Date of Patent: June 2, 2015Assignee: DALI SYSTEMS CO. LTD.Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton, Ying Xiao
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Publication number: 20150092830Abstract: 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: ApplicationFiled: September 8, 2014Publication date: April 2, 2015Inventors: Wan-Jong Kim, Kyoung Joon Cho, Jong Heon Kim, Shawn Patrick Stapleton
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Publication number: 20150080054Abstract: 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: ApplicationFiled: July 18, 2014Publication date: March 19, 2015Applicant: DALI SYSTEMS CO. LTD.Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton, Ying Xiao
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Publication number: 20150010110Abstract: 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: ApplicationFiled: July 21, 2014Publication date: January 8, 2015Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Ying Xiao
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Patent number: 8903337Abstract: 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: GrantFiled: May 15, 2013Date of Patent: December 2, 2014Assignee: Dali Systems Co. Ltd.Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton
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Publication number: 20140327481Abstract: 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: ApplicationFiled: May 7, 2014Publication date: November 6, 2014Applicant: DALI SYSTEMS CO., LTD.Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Jong Heon Kim, Dali Yang
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Patent number: 8855234Abstract: 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: GrantFiled: May 3, 2013Date of Patent: October 7, 2014Assignee: Dali Systems Co. Ltd.Inventors: Wan Jong Kim, Kyoung Joon Cho, Jong Heon Kim, Shawn Patrick Stapleton
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Patent number: 8824595Abstract: 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: GrantFiled: September 6, 2013Date of Patent: September 2, 2014Assignee: Dali Systems Co. Ltd.Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton, Ying Xiao
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Patent number: 8811917Abstract: 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: GrantFiled: April 23, 2008Date of Patent: August 19, 2014Assignee: Dali Systems Co. Ltd.Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Jong Heon Kim, Dali Yang
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Patent number: 8804870Abstract: 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: GrantFiled: December 21, 2010Date of Patent: August 12, 2014Assignee: Dali Systems Co. Ltd.Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Ying Xiao
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Publication number: 20140191805Abstract: 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: ApplicationFiled: November 22, 2013Publication date: July 10, 2014Applicant: Dali Systems Co., Ltd.Inventors: Kyoung Joon Cho, Wan Jong Kim, Shawn Patrick Stapleton
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Publication number: 20140079153Abstract: 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: ApplicationFiled: September 6, 2013Publication date: March 20, 2014Applicant: DALI SYSTEMS CO. LTD.Inventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton, Ying Xiao
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Patent number: 8618883Abstract: 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: GrantFiled: July 20, 2012Date of Patent: December 31, 2013Assignee: Dali Systems Co. Ltd.Inventors: Kyoung Joon Cho, Wan Jong Kim, Shawn Patrick Stapleton
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Publication number: 20130251066Abstract: 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: ApplicationFiled: May 15, 2013Publication date: September 26, 2013Applicant: DALI SYSTEMS CO., LTD., Maples Corporate Services LimitedInventors: Wan-Jong Kim, Kyoung-Joon Cho, Shawn Patrick Stapleton
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Patent number: 8542768Abstract: A remote radio head unit (RRU) 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 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: GrantFiled: December 21, 2010Date of Patent: September 24, 2013Assignee: Dali Systems Co. Ltd.Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Ying Xiao