Patents by Inventor David S. Wisherd

David S. Wisherd 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).

  • Publication number: 20070230424
    Abstract: A wireless local area network (WLAN) includes a server and receiver, which includes a radio frequency (RF) front-end circuit that receives wireless signals from the mobile nodes within the WLAN and detects baseband signals. A signal waveform detector edge detects a signal waveform and generates a trigger signal indicative of the modulation type, data format and time-of-arrival (TOA) information of a desired signal to be captured. A baseband processor receives the trigger signal from the signal waveform detector and captures the desired signal. A system controller is connected to the baseband processor and configures the baseband processor for processing the desired signal and obtaining message data and signal metrics that are transferred to the system controller to be communicated outbound from the receiver as a client to the server.
    Type: Application
    Filed: March 28, 2007
    Publication date: October 4, 2007
    Applicant: WHERENET CORP.
    Inventor: David S. Wisherd
  • Patent number: 7212563
    Abstract: A location system includes a plurality of signal readers for receiving signals from a wireless transmitter to be located. The signals include a wideband, spread spectrum signal and a timing marker appended a predetermined time in front of the wideband, spread spectrum signal for indicating the presence of the wideband, spread spectrum signal. A location processor is operatively coupled to the signal readers for detecting the timing markers of signals and responsive to a detection of a timing marker, correlating a signal as a first-to-arrive signal and conducting differentiation of first-to-arrive signals to locate a wireless transmitter.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: May 1, 2007
    Assignee: Wherenet Corp
    Inventors: Robert W. Boyd, Donald K. Belcher, Michael A. Wohl, David S. Wisherd
  • Patent number: 6593885
    Abstract: A time division multiplexed reader to shared RF channel processor signal transport network for a geolocation system in which the number of readers is relatively small, allowing the use of only a single shared RF channel processor. The differential signal transport delays among respective segments of the network creates an inherent set of time division multiplexed time slots for the various readers, that allows the shared RF channel processor to receive and process the output of each reader in a known, independent time frame.
    Type: Grant
    Filed: April 20, 2001
    Date of Patent: July 15, 2003
    Assignee: Wherenet Corp
    Inventors: David S. Wisherd, Donald K. Belcher
  • Publication number: 20020181565
    Abstract: A location system includes a plurality of signal readers for receiving signals from a wireless transmitter to be located. The signals include a wideband, spread spectrum signal and a timing marker appended a predetermined time in front of the wideband, spread spectrum signal for indicating the presence of the wideband, spread spectrum signal. A location processor is operatively coupled to the signal readers for detecting the timing markers of signals and responsive to a detection of a timing marker, correlating a signal as a first-to-arrive signal and conducting differentiation of first-to-arrive signals to locate a wireless transmitter.
    Type: Application
    Filed: May 3, 2002
    Publication date: December 5, 2002
    Applicant: WHERENET CORP
    Inventors: Robert W. Boyd, Donald K. Belcher, Michael A. Wohl, David S. Wisherd
  • Publication number: 20020039080
    Abstract: A time division multiplexed reader to shared RF channel processor signal transport network for a geolocation system in which the number of readers is relatively small, allowing the use of only a single shared RF channel processor. The differential signal transport delays among respective segments of the network creates an inherent set of time division multiplexed time slots for the various readers, that allows the shared RF channel processor to receive and process the output of each reader in a known, independent time frame.
    Type: Application
    Filed: April 20, 2001
    Publication date: April 4, 2002
    Applicant: Wherenet Corp
    Inventors: David S. Wisherd, Donald K. Belcher
  • Patent number: 5920287
    Abstract: An asset management radio location system uses time-of-arrival differentiation for random and repetitive spread spectrum, short duration pulse `blinks` from object-attached tags, to provide a practical, continuous identification of the location of each and every object within an environment of interest, irrespective whether the object is stationary or moving. Correlation-based RF processors determine which signals received by tag transmission readers are first-to-arrive signals as transmitted from any blinking tag, and an object location processor carries out time-of-arrival differentiation of these first-to-arrive transmissions from any blinking tag to determine where the respective object is located within the environment. A low power interrogation wand may be employed to refine the location of an object by a user programmed transmission-response exchange between the wand and the tag associated with the object of interest.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: July 6, 1999
    Assignee: Widata Corporation
    Inventors: Donald K. Belcher, John A. Eisenberg, David S. Wisherd
  • Patent number: 5338974
    Abstract: An RF power transistor is mounted on a ceramic substrate with a plurality of input leads extending from one edge of the substrate, a plurality of output leads extending from an opposite edge of the substrate, a plurality of input ground leads with ground leads positioned between adjacent input leads, and a plurality of output ground leads with ground lead positioned between adjacent output leads. All ground leads are ohmically connected with the current paths between adjacent ground leads reduced in length.
    Type: Grant
    Filed: March 17, 1993
    Date of Patent: August 16, 1994
    Assignee: Spectrian, Inc.
    Inventors: David S. Wisherd, Howard D. Bartlow
  • Patent number: 5315265
    Abstract: An RF power FET amplifier is designed using parasitic resonant matching to reduce low intermodulation distortion. An input inductor is connected in parallel with the capacitance of the common-source input capacitance, an output inductor is connected in parallel with the common-source output capacitance. Feedback provided by the common-source capacitance between gate and drain is utilized to improve linearization and stability. The field effect transistor is designed so that the feedback signal resulting from the feedback capacitance is 180.degree. with respect to the forward gain.
    Type: Grant
    Filed: December 11, 1992
    Date of Patent: May 24, 1994
    Assignee: Spectrian, Inc.
    Inventors: David S. Wisherd, William H. McCalpin
  • Patent number: 5304959
    Abstract: A planar balun including first and second spaced parallel elongated conductors on one surface of a ceramic, plastic, polymer, synthetic fiber or a composite substrate and a third elongated conductor on a second surface of the substrate opposite from the first and second conductors. The spacing from an outer edge of each of the first and second conductors to an outer edge of the third conductor being greater than the thickness of the ceramic substrate, and the spacing between the two parallel elongated conductors being greater than ##EQU1## The substrate is mounted on a metallic support plate which provides a ground plane spaced from the third conductor by a distance t2 in an atmosphere comprising air with the distance t2 being greater than ##EQU2## An input of the balun is at one end of the first and second conductors and an output of the balun is at the other end of the first and second conductors.
    Type: Grant
    Filed: October 16, 1992
    Date of Patent: April 19, 1994
    Assignee: Spectrian, Inc.
    Inventors: David S. Wisherd, Joseph M. O'Reilly, Brian L. Baskin
  • Patent number: 5272450
    Abstract: The frequency response of an RF power amplifier in a Cellular Phone Base station is improved by providing a shunt capacitor with the choke coil which interconnects a DC power source to the active device of the amplifier. The cutoff frequency of the bias network can be adjusted so that sum and difference frequencies of multiple-input signals are not attenuated by the feed network thereby permitting the sum and difference frequency signals to be shunted to ground. The linearity and bandwidth of the power amplifier is thus improved.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: December 21, 1993
    Assignee: Microwave Modules & Devices, Inc.
    Inventor: David S. Wisherd
  • Patent number: 5027082
    Abstract: An RF power device including a DMOS field effect transistor has increased efficiency and reduced distortion. A capacitor is connected between the gate and source input of the transistor which swamps non-linear variations of the parasitic capacitance (C.sub.GD) between the gate and drain, thereby offsetting the Miller effect of the feedback provided by the MOS transistor parasitic capacitance. The capacitor, the Ciss of the MOS transistor, and the inductance of input leads provide a device input resonant frequency between the input signal fundamental frequency and the first harmonic.
    Type: Grant
    Filed: May 1, 1990
    Date of Patent: June 25, 1991
    Assignee: Microwave Modules & Devices, Inc.
    Inventors: David S. Wisherd, Howard D. Bartlow, Pablo E. D'Anna
  • Patent number: D249689
    Type: Grant
    Filed: November 15, 1976
    Date of Patent: September 26, 1978
    Assignee: Communications Power, Inc.
    Inventors: David S. Wisherd, Stephen L. Mieth, Larry H. Mitchell