Patents by Inventor Changhyuk Cho

Changhyuk 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).

  • Publication number: 20130029614
    Abstract: Systems, methods, and apparatuses may provide for antenna switch controllers. An example antenna switch controller may include: a plurality of antenna switches commonly connected to one or more antennas, where each of the plurality of antenna switches includes a plurality of stacked transistors, where one of the plurality of antenna switches is enabled when transmitting or receiving one or more radio frequency (RF) signals via the one or more antennas; a voltage generator that receives an external supply voltage from a battery, where the voltage generator generates an internal supply voltage, where the internal supply voltage remains constant despite fluctuations in the external supply voltage from the battery; a clock buffer that generates clock signals from the constant internal supply voltage; and a charge pump that receives the clock signals and generates a constant negative voltage, where the constant negative voltage is for biasing of one or more of the plurality of antenna switches that are disabled.
    Type: Application
    Filed: July 29, 2011
    Publication date: January 31, 2013
    Applicant: SAMSUNG ELECTRO-MECHANICS COMPANY
    Inventors: Changhyuk Cho, Jeongwon Cha, Minsik Ahn, Chang-Ho Lee, Wyangmyong Woo, Jae Joon Chang
  • Patent number: 8334708
    Abstract: Example driver circuits can utilize shared-charge recycling charge pump structures. In particular, an example shared-charge recycling process may be applied to a clock buffer and charge transfer cells of the charge pump in a driver circuit. An example recycling process may include recycling of shared charges between the capacitors/capacitances in the charge transfer cells. An example recycling process may use the charges in one or more capacitors to charge one or more other capacitors before the charges are wasted or otherwise discharged to ground. Such recycling may significantly reduce the power consumption of the charge pump while still providing a high output voltage level, according to an example embodiment of the invention.
    Type: Grant
    Filed: July 29, 2011
    Date of Patent: December 18, 2012
    Assignee: Samsung Electro-Mechanics
    Inventors: Jeongwon Cha, Taejoong Song, Changhyuk Cho, Minsik Ahn, Chang-Ho Lee, Wangmyong Woo, Jae Joon Chang
  • Patent number: 7890063
    Abstract: Embodiments of the invention may provide for a CMOS antenna switch, which may be referred to as a CMOS SP4T switch. The CMOS antenna switch may operate at a plurality of frequencies, perhaps around 900 MHz and 1.9 GHz according to an embodiment of the invention. The CMOS antenna switch may include both a receiver switch and a transmit switch. The receiver switch may utilize a multi-stack transistor with body substrate tuning to block high power signals from the transmit path as well as to maintain low insertion loss at the receiver path. On the other hand, in the transmit switch, a body substrate tuning technique may be applied to maintain high power delivery to the antenna. Example embodiments of the CMOS antenna switch may provide for 31 dBm P 1 dB at both bands (e.g., 900 MHz and 1.8 GHz). In addition, a 0.9 dB and ?1.1 dB insertion loss at 900 MHz and 1.9 GHz, respectively, may be obtained according to example embodiments of the invention.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: February 15, 2011
    Assignees: Samsung Electro-Mechanics, Georgia Tech Research Corporation
    Inventors: Minsik Ahn, Chang-Ho Lee, Changhyuk Cho, Jaejoon Chang, Wangmyong Woo, Haksun Kim, Joy Laskar
  • Patent number: 7772816
    Abstract: Embodiments of the invention may provide for a load regulation tuner that reduces the load regulation effect. The load regulation tuner may include a load current controlled current source that is responsive to a load current from a power transistor of a linear regulator, where the load current controlled current source includes a sensing transistor that generates a fraction of the load current as a sensed partial load current. The load regulation tuner may also include a resistor in parallel with a load current controlled current source, and where the paralleled resistor and the load current controlled current source form at least a portion of a feedback block that adjusts an operation of the linear regulator to provide a substantially constant load voltage.
    Type: Grant
    Filed: October 15, 2007
    Date of Patent: August 10, 2010
    Assignees: Samsung Electro-Mechanics, Georgia Tech Research Corporation
    Inventors: Changhyuk Cho, Chang-Ho Lee, Jaejoon Chang, Wangmyong Woo, Haksun Kim, Joy Laskar
  • Publication number: 20080088286
    Abstract: Embodiments of the invention may provide for a load regulation tuner that reduces the load regulation effect. The load regulation tuner may include a load current controlled current source that is responsive to a load current from a power transistor of a linear regulator, where the load current controlled current source includes a sensing transistor that generates a fraction of the load current as a sensed partial load current. The load regulation tuner may also include a resistor in parallel with a load current controlled current source, and where the paralleled resistor and the load current controlled current source form at least a portion of a feedback block that adjusts an operation of the linear regulator to provide a substantially constant load voltage.
    Type: Application
    Filed: October 15, 2007
    Publication date: April 17, 2008
    Inventors: Changhyuk Cho, Chang-Ho Lee, Jaejoon Chang, Wangmyong Woo, Haksun Kim, Joy Laskar
  • Publication number: 20080079653
    Abstract: Embodiments of the invention may provide for a CMOS antenna switch, which may be referred to as a CMOS SP4T switch. The CMOS antenna switch may operate at a plurality of frequencies, perhaps around 900 MHz and 1.9 GHz according to an embodiment of the invention. The CMOS antenna switch may include both a receiver switch and a transmit switch. The receiver switch may utilize a multi-stack transistor with body substrate tuning to block high power signals from the transmit path as well as to maintain low insertion loss at the receiver path. On the other hand, in the transmit switch, a body substrate tuning technique may be applied to maintain high power delivery to the antenna. Example embodiments of the CMOS antenna switch may provide for 31 dBm P 1 dB at both bands (e.g., 900 MHz and 1.8 GHz). In addition, a 0.9 dB and ?1.1 dB insertion loss at 900 MHz and 1.9 GHz, respectively, may be obtained according to example embodiments of the invention.
    Type: Application
    Filed: September 18, 2007
    Publication date: April 3, 2008
    Inventors: Minsik Ahn, Chang-Ho Lee, Changhyuk Cho, Jaejoon Chang, Wangmyong Woo, Haksun Kim, Joy Laskar