Changhyuk Cho

US Patent:

7890063, Feb 15, 2011

Filed:

Sep 18, 2007

Appl. No.:

11/857322

Inventors:

Minsik Ahn - Atlanta GA, US
Chang-Ho Lee - Marietta GA, US
Changhyuk Cho - Roswell GA, US
Jaejoon Chang - Duluth GA, US
Haksun Kim - Daejeon, KR
Joy Laskar - Marietta GA, US

Assignee:

Samsung Electro-Mechanics
Georgia Tech Research Corporation - Atlanta GA

International Classification:

H04B 1/44

US Classification:

455 78

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.

US Patent:

8334708, Dec 18, 2012

Filed:

Jul 29, 2011

Appl. No.:

13/194315

Inventors:

Jeongwon Cha - Duluth GA, US
Taejoong Song - Seongnam-si, KR
Changhyuk Cho - Roswell GA, US
Minsik Ahn - Atlanta GA, US
Chang-Ho Lee - Marietta GA, US
Jae Joon Chang - Duluth GA, US

Assignee:

Samsung Electro-Mechanics - Gyunngi-Do

International Classification:

H03K 19/00
H03K 19/02

US Classification:

326 58, 326 56, 326 33

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.

US Patent:

20080088286, Apr 17, 2008

Filed:

Oct 15, 2007

Appl. No.:

11/872519

Inventors:

Changhyuk Cho - Roswell GA, US
Chang-Ho Lee - Marietta GA, US
Jaejoon Chang - Duluth GA, US
Haksun Kim - Daejeon, KR
Joy Laskar - Marietta GA, US

International Classification:

G05F 1/565

US Classification:

323280000, 323275000

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.

US Patent:

20130029614, Jan 31, 2013

Filed:

Jul 29, 2011

Appl. No.:

13/194325

Inventors:

Changhyuk Cho - Roswell GA, US
Jeongwon Cha - Duluth GA, US
Minsik Ahn - Atlanta GA, US
Chang-Ho Lee - Marietta GA, US
Jae Joon Chang - Duluth GA, US

Assignee:

SAMSUNG ELECTRO-MECHANICS COMPANY - Gyunggi-Do

International Classification:

H04B 1/44

US Classification:

455 83

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.