Patents by Inventor Chi Wah Kok

Chi Wah Kok 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: 11316576
    Abstract: A wireless communication system and a precoder device for use in such system. The precoder device includes a delay element arranged to introduce a delay to a plurality of sub-channels of a signal at a transmitter end of the communication system; wherein the delay in a plurality of sub-channels are associated with a process time of a receiver component at a receiver end of the communication system.
    Type: Grant
    Filed: October 30, 2019
    Date of Patent: April 26, 2022
    Assignee: City University of Hong Kong
    Inventors: Chi Wah Kok, Wing Shan Tam, Wai Ming Chan, Hing Cheung So
  • Publication number: 20210135731
    Abstract: A wireless communication system and a precoder device for use in such system. The precoder device includes a delay element arranged to introduce a delay to a plurality of sub-channels of a signal at a transmitter end of the communication system; wherein the delay in a plurality of sub-channels are associated with a process time of a receiver component at a receiver end of the communication system.
    Type: Application
    Filed: October 30, 2019
    Publication date: May 6, 2021
    Inventors: Chi Wah Kok, Wing Shan Tam, Wai Ming Chan, Hing Cheung So
  • Patent number: 8547168
    Abstract: Systems, methods, and devices that employ a dynamic gate boost component (DGBC) to generate a desired boosted gate voltage to facilitate controlling an enhanced charge pump are presented. An enhanced charge pump can comprise a desired number of charge transfer switches (CTSs) and a desired number of DGBCs, wherein a DGBC can apply a desired boosted gate voltage to the gate of an associated CTS to control switching of the CTS. An auxiliary gate boost component (AGBC) of one circuit path can apply a desired boosted gate voltage to a CTS of another circuit path to control switching of that CTS. The AGBC and DGBC can operate to facilitate maintaining the overdrive voltages of all of the CTSs in the enhanced charge pump so that the overdrive voltages are essentially unchanged under various loading current conditions. Multiple enhanced charge pumps can be cascaded to produce a higher output voltage.
    Type: Grant
    Filed: October 14, 2011
    Date of Patent: October 1, 2013
    Assignee: Jen-Ai Holdings, LLC
    Inventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
  • Publication number: 20130093503
    Abstract: Systems, methods, and devices that employ a dynamic gate boost component (DGBC) to generate a desired boosted gate voltage to facilitate controlling an enhanced charge pump are presented. An enhanced charge pump can comprise a desired number of charge transfer switches (CTSs) and a desired number of DGBCs, wherein a DGBC can apply a desired boosted gate voltage to the gate of an associated CTS to control switching of the CTS. An auxiliary gate boost component (AGBC) of one circuit path can apply a desired boosted gate voltage to a CTS of another circuit path to control switching of that CTS. The AGBC and DGBC can operate to facilitate maintaining the overdrive voltages of all of the CTSs in the enhanced charge pump so that the overdrive voltages are essentially unchanged under various loading current conditions. Multiple enhanced charge pumps can be cascaded to produce a higher output voltage.
    Type: Application
    Filed: October 14, 2011
    Publication date: April 18, 2013
    Applicant: CANAAN MICROELECTRONICS CORPORATION LIMITED
    Inventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
  • Patent number: 8362824
    Abstract: Described herein are switched capacitor charge pump designs for a 2n× voltage converter. The 2n× voltage converter is constructed by cascading n units of substantially identical unit cells, which are respectively composed of cross-coupled single cell doubler circuits. Dynamic inverters are used to completely activate and deactivate the power switches in the respective unit cells to increase area efficiency. The charge pump designs described herein are implemented with standard high-voltage CMOS processes without requiring MOSFET transistors with different threshold voltages, giving the charge pump a regular structure that simplifies design and layout and reduces production costs. In addition, techniques for constructing a charge pump according to the designs provided herein are described.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: January 29, 2013
    Assignee: Canaan Microelectronics Corporation Limited
    Inventors: Oi Ying Wong, Wing Shan Tam, Chi Wah Kok
  • Patent number: 8339184
    Abstract: Systems, methods, and devices that generate a desired boosted gate voltage to facilitate controlling a charge pump are presented. A multi-phase charge pump (e.g., two-phase CMOS charge pump) can comprise a desired number of switch cells (SCs), wherein each SC can include a gate boost switch control component, which employs two transistors (without the need for external circuitry), and generates a desired gate voltage, based at least in part on a desired clock signal, wherein the desired gate voltage is applied to a charge transfer switch, Mc, of the SC to facilitate transferring a voltage across the Mc to a node on the other side of the Mc, in each stage of the charge pump, wherein the SCs are associated with a desired number of flying capacitors to facilitate increasing the input voltage to a desired output voltage.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: December 25, 2012
    Assignee: Canaan Microelectronics Corporation Limited
    Inventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
  • Publication number: 20120105137
    Abstract: Systems, methods, and devices that generate a desired boosted gate voltage to facilitate controlling a charge pump are presented. A multi-phase charge pump (e.g., two-phase CMOS charge pump) can comprise a desired number of switch cells (SCs), wherein each SC can include a gate boost switch control component, which employs two transistors (without the need for external circuitry), and generates a desired gate voltage, based at least in part on a desired clock signal, wherein the desired gate voltage is applied to a charge transfer switch, Mc, of the SC to facilitate transferring a voltage across the Mc to a node on the other side of the Mc, in each stage of the charge pump, wherein the SCs are associated with a desired number of flying capacitors to facilitate increasing the input voltage to a desired output voltage.
    Type: Application
    Filed: October 29, 2010
    Publication date: May 3, 2012
    Applicant: CANAAN MICROELECTRONICS CORPORATION LIMITED
    Inventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
  • Publication number: 20110285455
    Abstract: Described herein are switched capacitor charge pump designs for a 2n× voltage converter. The 2n× voltage converter is constructed by cascading n units of substantially identical unit cells, which are respectively composed of cross-coupled single cell doubler circuits. Dynamic inverters are used to completely activate and deactivate the power switches in the respective unit cells to increase area efficiency. The charge pump designs described herein are implemented with standard high-voltage CMOS processes without requiring MOSFET transistors with different threshold voltages, giving the charge pump a regular structure that simplifies design and layout and reduces production costs. In addition, techniques for constructing a charge pump according to the designs provided herein are described.
    Type: Application
    Filed: December 15, 2010
    Publication date: November 24, 2011
    Applicant: CANAAN MICROELECTRONICS CORPORATION LIMITED
    Inventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
  • Patent number: 7969493
    Abstract: An active pixel sensor includes a photosensitive device and a dynamic comparator that when coupled with a voltage ramp will form a digital pixel sensor with pulse width modulated digital output. A number of switches are included in the digital pixel sensor to configure the input of the dynamic comparator to couple with the photosensitive device or the voltage ramp such that the dynamic comparator is free from input transistor mismatch problem, as both input use the same input transistor. A cascade of dynamic comparator is disclosed in this invention, such as to improve the sensitivity and conversion speed of the digital pixel sensor. There are a number of switches that connect and isolate the digital pixel sensor from the bit line, which is shared by a plurality of digital pixel sensors in the sensor array. Photosensitive devices in close proximity can share the dynamic comparator by a number of selection switches, such that each photosensitive device can be read out in a time shared manner.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: June 28, 2011
    Assignee: Intellectual Ventures Fund 27 LLC
    Inventor: Chi Wah Kok
  • Patent number: 7652374
    Abstract: A semiconductor package structure for flip chip package includes at least a patterned circuit layer and an insulating layer alternately stacking up each other. The patterned layer includes a plurality of bump pads, and the insulating layer includes a plurality of etching holes. The etching holes and the bump pads are aligned, such that the bump pads are exposed through the etching holes. A plurality of bumps is disposed on the active surface of the chip, which can be obtained by stud bumping. The etching holes are filled with solder paste, and the bumps of the chips penetrate into the solder filled etching holes. Vibration obtained by mechanical equipment, or ultrasonic equipment can be applied to assist the alignment of the bumps to the corresponding bump pads. A reflow process is applied to collapse the solder paste that fills the etching holes to form electrical connection between the bumps and bump pads.
    Type: Grant
    Filed: July 31, 2006
    Date of Patent: January 26, 2010
    Inventors: Chi Wah Kok, Yee Ching Tam
  • Patent number: 7602429
    Abstract: Imaging devices—as well as methods for operating such devices—that include active pixel sensors and a transistor that, when paired with the transistor in an adjacent pixel, will form a differential input pair of an operational amplifier. At least some portion of the operational amplifier circuit is located off the active pixel sensor, and shared by the rows or columns of the active pixel sensor array.
    Type: Grant
    Filed: February 1, 2006
    Date of Patent: October 13, 2009
    Inventor: Chi Wah Kok
  • Patent number: 7414562
    Abstract: An asynchronous cyclic current-mode analog-to-digital converter (ADC) is disclosed. The ADC comprises a plurality of sub-ADCs cascading from the first stage to the last stage, each sub-ADC comprising a current-mode ADC having a digital output, an analog current input, a reference current input and an analog current output. The analog current input of each stage, except the first stage, is operatively connected to the analog current output of the immediately preceding stage. The plurality of sub-ADCs are configured to operate without synchronization with each other.
    Type: Grant
    Filed: July 25, 2006
    Date of Patent: August 19, 2008
    Assignee: Intellectual Ventures Fund 27 LLC
    Inventors: Chi Wah Kok, Wing Shan Tam
  • Patent number: 7405606
    Abstract: A D flip-flop with a reduced power product or reduced clock line capacitance is disclosed. The flip-flop includes a half-static slave stage or a master stage with clock gating by the input and output. The half-static slave stage an output inverter and a feedback element consisting of a single switching transistor having a gate connected to the output of the flip-flop and the input of the inverter as its load. The clock gating circuit, which may comprise an XNOR gate, reduces the frequency of switching events by permitting clock pulses to pass into the master or slave stage only when the input and output of the flip-flop are at the same logical state.
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: July 29, 2008
    Assignee: Intellectual Ventures Fund 27 LLC
    Inventors: Chi Wah Kok, Yee Ching Tam
  • Publication number: 20080024346
    Abstract: An asynchronous cyclic current-mode analog-to-digital converter (ADC) is disclosed. The ADC comprises a plurality of sub-ADCs cascading from the first stage to the last stage, each sub-ADC comprising a current-mode ADC having a digital output, an analog current input, a reference current input and an analog current output. The analog current input of each stage, except the first stage, is operatively connected to the analog current output of the immediately preceding stage. The plurality of sub-ADCs are configured to operate without synchronization with each other.
    Type: Application
    Filed: July 25, 2006
    Publication date: January 31, 2008
    Applicant: Promax Technology (Hong Kong) Limited
    Inventors: Chi Wah Kok, Wing Shan Tam
  • Publication number: 20080023829
    Abstract: A semiconductor package structure for flip chip package includes at least a patterned circuit layer and an insulating layer alternately stacking up each other. The patterned layer includes a plurality of bump pads, and the insulating layer includes a plurality of etching holes. The etching holes and the bump pads are aligned, such that the bump pads are exposed through the etching holes. A plurality of bumps is disposed on the active surface of the chip, which can be obtained by stud bumping. The etching holes are filled with solder paste, and the bumps of the chips penetrate into the solder filled etching holes. Vibration obtained by mechanical equipment, or ultrasonic equipment can be applied to assist the alignment of the bumps to the corresponding bump pads. A reflow process is applied to collapse the solder paste that fills the etching holes to form electrical connection between the bumps and bump pads.
    Type: Application
    Filed: July 31, 2006
    Publication date: January 31, 2008
    Applicant: Promax Technology (Hong Kong) Limited
    Inventors: Chi Wah Kok, Yee Ching Tam
  • Publication number: 20050288923
    Abstract: The invention provides a method and apparatus for noise reduction of a signal, for example speech enhancement of a speech signal. The method involves a two-stage algorithm comprising performing a preprocessing first spectral subtraction to remove tonal noise and generate a tonal noise removed signal, and performing a second spectral subtraction to remove noise from the said tonal noise removed signal. In both spectral subtraction stages noise is not removed completely but only to a level below an audible threshold in order to avoid unwanted artifacts.
    Type: Application
    Filed: June 25, 2004
    Publication date: December 29, 2005
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventor: Chi-Wah Kok
  • Patent number: 6642932
    Abstract: A method is proposed for converting a multicolor image in which each pixel has a color intensity value for only a single color, into a full color image. For pixels for which the intensity value of a first color is known, the intensity value of a second (missing) color is interpolated as the intensity value of the first color multiplied by the local average intensity of the second color and divided by the local average intensity of the first color. Each of the intensity values of the first and second color values is determined over a set of nearest neighboring pixels. The smoothing artifact produced by the proposed method is much less than some known algorithms described above, but the computational complexity of the proposed method is low.
    Type: Grant
    Filed: September 13, 2001
    Date of Patent: November 4, 2003
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Chi Wah Kok, Suk Han Lam
  • Publication number: 20030048279
    Abstract: A method is proposed for converting a multicolor image in which each pixel has a color intensity value for only a single color, into a full color image. For pixels for which the intensity value of a first color is known, the intensity value of a second (missing) color is interpolated as the intensity value of the first color multiplied by the local average intensity of the second color and divided by the local average intensity of the first color. Each of the intensity values of the first and second color values is determined over a set of nearest neighboring pixels. The smoothing artifact produced by the proposed method is much less than some known algorithms described above, but the computational complexity of the proposed method is low.
    Type: Application
    Filed: September 13, 2001
    Publication date: March 13, 2003
    Inventors: Chi Wah Kok, Suk Han Lam
  • Patent number: 6489995
    Abstract: An innovative method and apparatus for decoding an encoded image such as a video. In one embodiment a method for decoding an encoded block of an image, e.g.,a video frame, having an error in its motion vector is disclosed. Sub-blocks are extracted from neighboring blocks to the encoded block. A motion vector is generated for each sub-portion and the generated motion vectors are used, for example, averaged, to estimate a motion vector for the encoded portion.
    Type: Grant
    Filed: October 22, 1998
    Date of Patent: December 3, 2002
    Assignees: Sony Corporation, Sony Electronics Inc.
    Inventors: Chi Wah Kok, Ning Lu
  • Patent number: 6363117
    Abstract: The present invention provides fast block motion estimation. In one embodiment, a process for fast block motion estimation decimates search locations in a hierarchical manner to reduce the computational complexity of block motion estimation. Different search window sizes and decimation patterns are used at different stages of the search. The use of a large window size in the first stage and different decimation patterns in the following stages reduces the risk of being trapped in local minima. In one embodiment, the process for fast motion estimation uses fast stopping criteria for search locations near the center of the search window, which makes the process center-biased. The average number of search locations examined for each block motion estimation is computationally efficient, and the block motion estimation accuracy is of high quality.
    Type: Grant
    Filed: December 31, 1998
    Date of Patent: March 26, 2002
    Assignees: Sony Corporation, Sony Electronics Inc.
    Inventor: Chi Wah Kok