Patents by Inventor Vernon R. Brethour

Vernon R. Brethour 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: 6763057
    Abstract: An apparatus and method for communicating information using an ultra wideband impulse radio transmitter and receiver is disclosed. The method includes the steps of generating and transmitting a series of time-modulated pulses, each pulse delayed by one of four predetermined time delay periods and representative of at least two data bits of information, and receiving and demodulating the series of time-modulated pulses to estimate the data bits associated with each pulse. The apparatus includes an impulse radio transmitter and an impulse radio receiver. The transmitter transmits the series of time-modulated pulses and includes a transmitter time base, a time delay modulator, a code time modulator, an output stage, and a transmitting antenna. The receiver receives and demodulates the series of time-modulated pulses using a receiver time base and two correlators, one correlator designed to operate after a pre-determined delay with respect to the other correlator.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: July 13, 2004
    Assignee: Time Domain Corporation
    Inventors: Larry W. Fullerton, James L. Richards, Ivan A. Cowie, Vernon R. Brethour
  • Patent number: 6677796
    Abstract: A system and method of implementing precision time delays that provides important and novel improvements over prior techniques of implementing time delays by utilizing a new strategy for selecting the values in the sine and cosine lookup tables. Sine and cosine values which result in non-uniform amplitudes enable increased overall accuracy with fewer bits communicated from the look-up tables to the analogue portion of the system. Further, herein is provided the addition of a variable amplitude threshold crossing capability following the combining of the sine and cosine signals. The time delay accuracy of the resulting phase and amplitude hybrid system can be improved either by increasing the number of bits in the sine/cosine phase management section or by increasing the number of bits in the amplitude section. There is provided herein an optimum strategy for choosing the number of bits used in the phase and amplitude sections for the best overall delay accuracy with the fewest overall control bits.
    Type: Grant
    Filed: September 20, 2001
    Date of Patent: January 13, 2004
    Assignee: Time Domain Corp.
    Inventors: Vernon R. Brethour, Marcus H. Pendergrass, Ryan N. Confer
  • Publication number: 20030053572
    Abstract: A system and method of implementing precision time delays that provides important and novel improvements over prior techniques of implementing time delays by utilizing a new strategy for selecting the values in the sine and cosine lookup tables. Sine and cosine values which result in non-uniform amplitudes enable increased overall accuracy with fewer bits communicated from the look-up tables to the analogue portion of the system. Further, herein is provided the addition of a variable amplitude threshold crossing capability following the combining of the sine and cosine signals The time delay accuracy of the resulting phase and amplitude hybrid system can be improved either by increasing the number of bits in the sine/cosine phase management section or by increasing the number of bits in the amplitude section. There is provided herein an optimum strategy for choosing the number of bits used in the phase and amplitude sections for the best overall delay accuracy with the fewest overall control bits.
    Type: Application
    Filed: September 20, 2001
    Publication date: March 20, 2003
    Inventors: Vernon R. Brethour, Marcus H. Pendergrass, Ryan N. Confer
  • Patent number: 6529568
    Abstract: An impulse radio concurrently receives an impulse signal and interference. An interference sampler samples the interference before an expected time of arrival of an impulse in the impulse signal, to produce an interference nulling sample. Then, when the impulse arrives, a data sampler samples the impulse in the presence of the interference to produce a data sample including undesired interference energy. The anticipatory nulling sample is an estimate of the undesired interference energy captured in the subsequent data sample so that the nulling sample can be used to cancel the interference energy from the data sample. When the nulling sample precedes the data sample by an odd number of half cycle periods of the interference, the nulling sample is additively combined with the data sample to derive a corrected data sample, from which a portion of the interference energy is canceled.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: March 4, 2003
    Assignee: Time Domain Corporation
    Inventors: James L. Richards, Vernon R. Brethour, Jack Thomas Matheney
  • Publication number: 20020075972
    Abstract: Apparatus, systems and methods for transmitting and receiving one-of-many positions modulated impulse radio signals. An impulse radio receiver for demodulating a received impulse radio signal that is modulated according to a one-of-N positions modulation scheme, where N is the number of different possible positions where an impulse can be located within each time frame of the impulse radio signal, comprises a timing generator, one or more samplers and a data detector. The timing generator generates N timing signal, wherein each of the N timing signals is separated in time by more than ½ the width of impulses of the received impulse radio signal. The one or more samplers are triggered to sample the received impulse radio signal in accordance with the N timing signal and to provide a first to Nth sampler outputs. The data detector produces a demodulation decisions based on the first to Nth sampler outputs.
    Type: Application
    Filed: June 7, 2001
    Publication date: June 20, 2002
    Applicant: Time Domain Corporation
    Inventors: James L. Richards, Vernon R. Brethour, Jack T. Matheney
  • Publication number: 20020061081
    Abstract: Potential interference is reduced in an impulse radio. A signal including an impulse signal and potential interference is received by the impulse radio. The impulse signal includes a sequence of impulses. The sequence of impulses of the received signal is sampled at a sequence of data sample times to produce a sequence of data samples. The received signal is also sampled at a plurality of time offsets from each of the data sample times to produce a plurality of nulling samples corresponding to each of the data samples. Each of the data samples is then separately combined with the corresponding plurality of nulling samples to produce a sequence of adjusted samples.
    Type: Application
    Filed: February 8, 2001
    Publication date: May 23, 2002
    Inventors: James L. Richards, Vernon R. Brethour, Marcus H. Pendergrass
  • Publication number: 20020061080
    Abstract: Potential interference is reduced in an impulse radio. A signal including an impulse signal and potential interference is received by the impulse radio. The impulse signal includes a sequence of impulses. The sequence of impulses of the received signal is sampled at a sequence of data sample times to produce a sequence of data samples. The received signal is also sampled at a plurality of time offsets from each of the data sample times to produce a plurality of nulling samples corresponding to each of the data samples. A separate sequence of nulling samples for each of the time offsets is thereby produced. Each of the data samples is then separately combined with a corresponding nulling sample from each of the separate sequences of nulling samples to produce a separate sequence of adjusted samples corresponding to each of the time offsets. A separate quality metric, representative of a signal-to-interference level, is then determined for each of the separate sequences of adjusted samples.
    Type: Application
    Filed: January 5, 2001
    Publication date: May 23, 2002
    Inventors: James L. Richards, Vernon R. Brethour
  • Patent number: 5636130
    Abstract: A method is provided for accurately determining the propagation delay of a gate under consideration in a static timing analyzer. This is accomplished by determining both the output load and input rise time of the gate under consideration. These values are then compared with a load versus rise time grid having previously determined values of propagation delay (points) for specified combinations of load and input rise time. These points are then used to interpolate a value of propagation delay for the gate under consideration by an interpolation technique that accounts for at least one of the following non-linear effects: the feed forward capacitance of a gate, soft switching, gate resistance, source and drain resistance, and/or other non-linear effects. The method accounts for each non-linear effect by imparting a corresponding component to propagation delay only in that range of output load and input rise time for which that non-linear effect is most pronounced.
    Type: Grant
    Filed: July 5, 1995
    Date of Patent: June 3, 1997
    Assignee: Sun Microsystems, Inc.
    Inventors: Raoul B. Salem, Vernon R. Brethour, Wen-Jay Hsu, Raymond A. Heald, Subramanian Ganesan