Patents Represented by Attorney, Agent or Law Firm Edward C. Kwok
  • Patent number: 7964932
    Abstract: A rectenna capable of power conversion from electromagnetic (EM) waves of high frequencies is provided. In one embodiment, a rectenna element generates currents from two sources—based upon the power of the incident EM wave and from an n-type semiconductor, or another electron source attached to a maximum voltage point of an antenna element. The combined current from both sources increases the power output of the antenna, thereby increasing the detection sensitivity of the antenna of a low power signal. Full wave rectification is achieved using a novel diode connected to a gap in the antenna element of a rectenna element. The diode is conductive at forward bias voltage or reverse bias voltage, and rectifies the antenna signal generated by the desired EM wave received by antenna raise from The rectenna element of the present invention may be used as a building block to create large rectenna arrays.
    Type: Grant
    Filed: October 7, 2005
    Date of Patent: June 21, 2011
    Inventors: Guy Silver, Juinerong Wu
  • Patent number: 6836241
    Abstract: A method in a Global Positioning System (GPS) receiver achieves enhanced performance by scheduling searches in the Doppler search space according to a cost function. The cost function relates to both the cost of building a 3-dimensional correlation grid and the cost of searching satellite, code phase, Doppler and integration time interval spaces for values that provide a maximum in the correlation grid. In one embodiment, after the clock Doppler is determined upon acquiring one satellite, the Doppler search range associated with a cell in the grid is dominated by the receiver's own motion. The scheduler schedules searching of the Doppler search space using search ranges determined empirically by the expected receiver velocity. In one embodiment, the scheduler increases integration times before changing Doppler search ranges, which require a recalculation of the grid.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: December 28, 2004
    Assignee: SiRF Technology, Inc.
    Inventors: Jesse Stone, Andrew Chou, Wallace Mann
  • Patent number: 6832087
    Abstract: The present invention provides a tunnel-based IP handoff process that can minimize the handoff latency associated with the standard Mobile IP registration. In the present invention, when neighboring nodes are detected, these detected nodes are identified as candidate nodes. Detection of just the existence of neighboring nodes should be possible even in situations where these neighboring nodes use different access technologies. For instance, pilot beacon signals may be taken as indication of the existence of candidate nodes although it may be impossible to compare them quantitatively if the beacon signals emanate from different access technologies. As soon as candidate nodes are identified, tunnels are established between the source node and the candidate nodes. The tunnels are used to forward data to the mobile node after a communication link between the mobile node and the source node goes down.
    Type: Grant
    Filed: June 28, 2002
    Date of Patent: December 14, 2004
    Assignee: NTT DoCoMo Inc.
    Inventors: Youngjune Gwon, Daichi Funato, Guangrui Fu, Atsushi Takeshita
  • Patent number: 6832140
    Abstract: Presented are a method and a system by which an individual can obtain usage information of a vehicle. A mobile unit, which may be located inside a vehicle, receives data from a part of the vehicle (e.g., the odometer) and/or Global Positioning System satellites and derives parameters such as the velocity and the travel distance from the received data. Using these parameters, the mobile unit may determine time information such as the amount of time the vehicle is traveling, in idle, or in a parked state within a given time period. Alternatively, the mobile unit may transmit the parameters to a remote computer, which then determines the time information. When a user submits a query requesting a parameter or a mathematical operation on a parameter, either the mobile unit or a remote computer prepares a response and transmits the response to the appropriate user interface.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: December 14, 2004
    Assignee: At Road, Inc.
    Inventors: Rodric C. Fan, Kenny Man D. Nguyen
  • Patent number: 6823082
    Abstract: A method of compressing digital representations of images stores the images in multiple subsampling quality scales in a progressive manner such that a higher quality scale contains only data incremental to the data in an adjacent lower quality scale. The data in each quality scale is transformed, quantized, and entropy encoded. A discrete wavelet cosine transformation combining frequency transformation features of a discrete cosine transformation and spatial transformation features of a wavelet transformation is provided. Sequences of subsampling quality scales are provided for multi-scale representations of images. A novel context selection method is used which treats color components and coefficients of different positions differently. An image compressed in a given quality scale can be transmitted or decompressed progressively allowing progressive downloading or transmission over the Internet.
    Type: Grant
    Filed: May 16, 2001
    Date of Patent: November 23, 2004
    Assignee: Boly Media Communications, Inc.
    Inventor: Xiaoping Hu
  • Patent number: 6809416
    Abstract: A method for enhancing thermal performance of an integrated circuit package attaches a dummy die to the semiconductor die of the integrated circuit. The dummy die is then thermally coupled through external terminals to the conductive layers of a printed circuit board. In one embodiment, the integrated circuit package includes an insulating substrate on which the dummy die is attached. Conductive vias thermally connect conductive terminals provided on one side of the insulating substrate to conductive terminals provided on the other side of the insulating substrate. In one embodiment, the integrated circuit package is provided as a ball grid array (BGA) package. In addition, multiple layers of conductors can be provided in both the insulating substrate of the integrated circuit and in the external printed circuit board.
    Type: Grant
    Filed: May 28, 2002
    Date of Patent: October 26, 2004
    Assignee: Intersil Corporation
    Inventor: Nirmal K. Sharma
  • Patent number: 6807660
    Abstract: A current waveform for an electronic circuit is calculated from a description of the circuit at a given level of abstraction without requiring a detailed simulation. In one embodiment, the waveform is estimated without using test vectors, and uses an analysis time step or “granularity” that is much shorter than a clock cycle. The method is applicable for calculating worst-case instantaneous current.
    Type: Grant
    Filed: October 1, 2002
    Date of Patent: October 19, 2004
    Assignee: Sequence Design, Inc.
    Inventor: Gerald L. Frenkil
  • Patent number: 6792061
    Abstract: A detector compares a first bit of a bit stream to a first bit of a pattern. If the first bit of the bit stream and the first bit of the pattern are the same, another detector is allowed to read a second bit of the bit stream and compare it to a second bit of the pattern. This continues until all bits of the pattern are detected. By performing the comparison as each bit of the bit stream arrives on a node, the present detectors are able to detect bit patterns in high-speed bit streams.
    Type: Grant
    Filed: August 21, 2000
    Date of Patent: September 14, 2004
    Assignee: BitBlitz Communications, Inc.
    Inventors: Yue-Hong Sutu, Bin Wu
  • Patent number: 6778556
    Abstract: A wireless communication network includes numerous mobile terminals and numerous transceivers (“base stations”). In this wireless communication network, messages sent from the base stations to the mobile terminals are transmitted at a higher data rate than the messages sent from the mobile terminals to the base stations. In one embodiment, a “half-duplex” protocol assigns separate times slots for base stations and mobile terminal transmissions. In another embodiment, a modified “full-duplex” protocol provides “half-duplex” operation in the mobile terminals and “full-duplex”operation in the base stations.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: August 17, 2004
    Assignee: GWCOM, Inc.
    Inventors: Raymond Chin, Weijia Wang, Arlin Torbett
  • Patent number: 6757429
    Abstract: A method of compressing digital representations of images stores the images in multiple subsampling quality scales in a progressive manner such that a higher quality scale contains only data incremental to the data in an adjacent lower quality scale. The data in each quality scale is transformed, quantized, and entropy encoded. A discrete wavelet cosine transformation combining frequency transformation features of a discrete cosine transformation and spatial transformation features of a wavelet transformation is provided. Sequences of subsampling quality scales are provided for multi-scale representations of images. A novel context selection method is used which treats color components and coefficients of different positions differently. An image compressed in a given quality scale can be transmitted or decompressed progressively allowing progressive downloading or transmission over the Internet.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: June 29, 2004
    Assignee: Boly Media Communications Inc.
    Inventor: Xiaoping Hu
  • Patent number: 6757610
    Abstract: A method for providing an initial estimate for an interval of possible values for a parameter used in an acquisition of a signal maintains parameter values obtained from previous signal acquisitions and the times at which the signal acquisitions were made. The maintained values of the parameter are used to derive a candidate value for the parameter to be used in a new signal acquisition. To make the maintained values available even after a brief period during which the GPS receiver is powered down, the maintained values can be stored in a non-volatile memory. The signal acquisitions may correspond to GPS satellite signal acquisitions, and the maintained parameter values can be grouped according to whether a successful receiver location determination was accomplished.
    Type: Grant
    Filed: February 4, 2002
    Date of Patent: June 29, 2004
    Assignee: SiRF Technology, Inc.
    Inventors: Wallace Mann, Jesse Stone
  • Patent number: 6754877
    Abstract: A method for optimal driver selection uses a cost function that is based on the non-linear delay characteristics and the stage gain of the candidate drivers. The cost function operates to select an optimal driver for driving the predetermined capacitive load which simultaneously minimizes the delay and the amount of input capacitance introduced. In one embodiment, a method for selecting a driver for driving a load capacitance from a group of drivers includes: computing for each driver a cost based on a cost function associated with the driver, and selecting the driver having the smallest cost. The cost function is directly proportional to a delay of the driver and inversely proportional to the logarithm of a stage gain of the driver. In another embodiment, the stage gain is an output capacitance driven by the driver (the load capacitance) divided by an input capacitance of the driver.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: June 22, 2004
    Assignee: Sequence Design, Inc.
    Inventor: Adi Srinivasan
  • Patent number: 6727732
    Abstract: A method and a circuit detect the presence of a high-speed signal, such as a high-speed differential signal, based on a software-programmable signal amplitude threshold. In one embodiment, when the amplitude threshold is exceeded, a current is generated to charge a capacitor. The voltage on the capacitor is compared to a second pre-set voltage in a low-speed comparator, which provides an output voltage indicating detection of the high-speed signal.
    Type: Grant
    Filed: September 18, 2002
    Date of Patent: April 27, 2004
    Assignee: BitBlitz Communications, Inc.
    Inventors: Bin Wu, Manoj N. Rana
  • Patent number: 6724342
    Abstract: In a mobile communication device, a method for compensating for a frequency adjustment in an oscillator shared between a communication circuit and a positioning signal receiver is provided. In one embodiment, the method begins to receive and store a positioning signal at a first time point. When, at a second time point, the operating frequency of the shared oscillator is adjusted, the frequency adjustment is recorded. After the positioning signal is completely received and stored, the processing of the positioning signal takes into consideration the frequency adjustment. In that embodiment, the processing hypothesizes a frequency shift in the received positioning signal. According to another aspect of the present invention, a method for determining the operating frequency of an oscillator detects a beginning time point of a reference signal received by the mobile communication device and enables a counter to count in step with a clock signal derived from the oscillator.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: April 20, 2004
    Assignee: SiRF Technology, Inc.
    Inventors: L. Scott Bloebaum, Piyush Bharti, Sherk Chung, Benjamin Van Roy, Wallace Mann
  • Patent number: 6711418
    Abstract: A wireless personal mobile terminal in a cellular data network includes a packet radio transceiver for communicating with cellular base stations and a paging receiver for receiving paging signals from a paging transmitter serving a large geographical area. The wireless personal mobile message unit has power-saving features built into the signal format. This personal mobile message unit accommodates many communication applications due to the high bandwidth and the low latency achieved in the cellular data network. Low-power operation and wide coverage is achieved using existing one-way paging infrastructure. The wireless personal mobile unit can be achieved inexpensively by modifying a conventional one-way pager.
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: March 23, 2004
    Assignee: General Wireless Communications Inc.
    Inventors: Weijia Wang, Nhan Tri Nguyen
  • Patent number: 6701505
    Abstract: A method is provided to optimize delay insertions for reducing timing violations. The method includes inserting a buffer between a driver and a receiver in a timing path and placing the buffer either inside or outside a bounding box that encloses the driver and the receiver. The placement of the buffer inside or outside the bounding box creates the appropriate effective loading on the buffer to generates the required minimum delay to avoid timing violations.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: March 2, 2004
    Assignee: Sequence Design, Inc.
    Inventor: Adi Srinivasan
  • Patent number: 6701506
    Abstract: A method for “match-delay” buffer insertion is provided to add delays at a node without changing the input capacitance of the node as seen by the upstream node. In one embodiment, a method for inserting a delay in a node in an electrical design associated with a logic gate includes: adding the delay at the node by adding a new logic gate before the node where the new logic gate is the same cell type as the logic gate and is positioned near the logic gate. The method may further include: determining if the delay can be added by adding a new logic gate before the node, and if a new logic gate cannot be added before the node, adding the delay by adding a new logic gate after the logic gate where a combination of the logic gate and the new logic gate giving the delay to be added.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: March 2, 2004
    Assignee: Sequence Design, Inc.
    Inventors: Adi Srinivasan, David L. Allen
  • Patent number: 6701507
    Abstract: A method for computing a position for a zero-skew driver insertion point in an area occupied by nodes driven by the driver is described. The zero-skew driver insertion point is the position in the area where the spread of the signal arrival times at the nodes driven by the driver is minimized. The method includes: expressing a function describing a distance from each of the nodes to the zero-skew driver insertion point, expressing the variance of the function, minimizing the variance of the function, and solving an equation representative of the minimization of the variance of the function to determine the position of the zero-skew driver insertion point. In one embodiment, the minimizing the variance of the function includes: taking a first derivative of the function with respect to the distance, and setting the first derivative of the function to zero.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: March 2, 2004
    Assignee: Sequence Design, Inc.
    Inventor: Adi Srinivasan
  • Patent number: 6698006
    Abstract: A clock tree insertion method for distributing a clock signal in an integrated circuit design includes providing a physical design representative of the integrated circuit design, specifying a location for a root node of the clock tree in the physical design, constructing an array of buffers as the clock tree where the array of buffers is constructed to minimize the maximum insertion delay from the root node to the clock signal endpoints and to meet a predefined maximum insertion delay constraint, identifying locations in the clock tree where clock skew violations occur and correcting the clock skew violations by introducing delay at buffer locations in the clock tree having the fastest clock signal arrival times, and identifying locations in the clock tree where minimum insertion delay violations occur and correcting the minimum insertion delay violations by slowing down the arrival times of clock signal endpoints of the clock tree.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: February 24, 2004
    Assignee: Sequence Design, Inc.
    Inventors: Adi Srinivasan, David L. Allen
  • Patent number: 6664922
    Abstract: A method for distributing locating-relevant information includes providing a GPS position of a client to a server on a data network, and returning location-relevant information by the server based on the specified GPS position. Such location-relevant information include travel or tourist information (e.g., locations of tourist attractions, hotels, or restaurants). Commercial information such as discount coupons or advertising selected based on the Client's GPS position can also be provided. Financial or business transactions can be conducted using the GPS position for authentication or identification.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: December 16, 2003
    Assignee: At Road, Inc.
    Inventor: Rodric C. Fan