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: 11316576Abstract: 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: GrantFiled: October 30, 2019Date of Patent: April 26, 2022Assignee: City University of Hong KongInventors: Chi Wah Kok, Wing Shan Tam, Wai Ming Chan, Hing Cheung So
-
Publication number: 20210135731Abstract: 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: ApplicationFiled: October 30, 2019Publication date: May 6, 2021Inventors: Chi Wah Kok, Wing Shan Tam, Wai Ming Chan, Hing Cheung So
-
Patent number: 8547168Abstract: 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: GrantFiled: October 14, 2011Date of Patent: October 1, 2013Assignee: Jen-Ai Holdings, LLCInventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
-
Publication number: 20130093503Abstract: 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: ApplicationFiled: October 14, 2011Publication date: April 18, 2013Applicant: CANAAN MICROELECTRONICS CORPORATION LIMITEDInventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
-
Patent number: 8362824Abstract: 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: GrantFiled: December 15, 2010Date of Patent: January 29, 2013Assignee: Canaan Microelectronics Corporation LimitedInventors: Oi Ying Wong, Wing Shan Tam, Chi Wah Kok
-
Patent number: 8339184Abstract: 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: GrantFiled: October 29, 2010Date of Patent: December 25, 2012Assignee: Canaan Microelectronics Corporation LimitedInventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
-
Publication number: 20120105137Abstract: 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: ApplicationFiled: October 29, 2010Publication date: May 3, 2012Applicant: CANAAN MICROELECTRONICS CORPORATION LIMITEDInventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
-
Publication number: 20110285455Abstract: 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: ApplicationFiled: December 15, 2010Publication date: November 24, 2011Applicant: CANAAN MICROELECTRONICS CORPORATION LIMITEDInventors: Chi Wah Kok, Oi Ying Wong, Wing Shan Tam
-
Patent number: 7969493Abstract: 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: GrantFiled: March 20, 2006Date of Patent: June 28, 2011Assignee: Intellectual Ventures Fund 27 LLCInventor: Chi Wah Kok
-
Patent number: 7652374Abstract: 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: GrantFiled: July 31, 2006Date of Patent: January 26, 2010Inventors: Chi Wah Kok, Yee Ching Tam
-
Patent number: 7602429Abstract: 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: GrantFiled: February 1, 2006Date of Patent: October 13, 2009Inventor: Chi Wah Kok
-
Patent number: 7414562Abstract: 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: GrantFiled: July 25, 2006Date of Patent: August 19, 2008Assignee: Intellectual Ventures Fund 27 LLCInventors: Chi Wah Kok, Wing Shan Tam
-
Patent number: 7405606Abstract: 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: GrantFiled: April 3, 2006Date of Patent: July 29, 2008Assignee: Intellectual Ventures Fund 27 LLCInventors: Chi Wah Kok, Yee Ching Tam
-
Publication number: 20080024346Abstract: 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: ApplicationFiled: July 25, 2006Publication date: January 31, 2008Applicant: Promax Technology (Hong Kong) LimitedInventors: Chi Wah Kok, Wing Shan Tam
-
Publication number: 20080023829Abstract: 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: ApplicationFiled: July 31, 2006Publication date: January 31, 2008Applicant: Promax Technology (Hong Kong) LimitedInventors: Chi Wah Kok, Yee Ching Tam
-
Publication number: 20050288923Abstract: 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: ApplicationFiled: June 25, 2004Publication date: December 29, 2005Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGYInventor: Chi-Wah Kok
-
Patent number: 6642932Abstract: 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: GrantFiled: September 13, 2001Date of Patent: November 4, 2003Assignee: The Hong Kong University of Science and TechnologyInventors: Chi Wah Kok, Suk Han Lam
-
Publication number: 20030048279Abstract: 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: ApplicationFiled: September 13, 2001Publication date: March 13, 2003Inventors: Chi Wah Kok, Suk Han Lam
-
Patent number: 6489995Abstract: 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: GrantFiled: October 22, 1998Date of Patent: December 3, 2002Assignees: Sony Corporation, Sony Electronics Inc.Inventors: Chi Wah Kok, Ning Lu
-
Patent number: 6363117Abstract: 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: GrantFiled: December 31, 1998Date of Patent: March 26, 2002Assignees: Sony Corporation, Sony Electronics Inc.Inventor: Chi Wah Kok