Patents by Inventor Daniel W. Tam

Daniel W. Tam 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: 9863989
    Abstract: A system includes a bottle, a first wire, a second wire, a current probe and an output line. The bottle holds a dielectric liquid therein. The first wire is disposed longitudinally on the bottle and generates a first oscillating electrical current in response to an electromagnetic wave, wherein the first oscillating electrical current thereby generates a corresponding first oscillating magnetic field. The second wire is disposed in parallel with the first wire on the bottle and generates a second oscillating electrical current in response to the electromagnetic wave, wherein the second oscillating electrical current thereby generating a corresponding second oscillating magnetic field. The current probe is arranged to surround the bottle such that the bottle is rotatable within the current probe or such that the current probe is rotatable around the bottle.
    Type: Grant
    Filed: August 18, 2016
    Date of Patent: January 9, 2018
    Assignee: The United States of America as represented by Secretary of the Navy
    Inventors: Daniel W. Tam, Marcus L. Maurer, Randall A. Reeves
  • Patent number: 9509052
    Abstract: An antenna comprising: a transceiver; a current probe operatively coupled to the transceiver, wherein the current probe comprises an outer conductive non-magnetic housing, a toroidal magnetic core having a central aperture, wherein the core is insulated from the housing, and a primary winding wound about the core; and an animal body, a portion of which is positioned within the aperture such that incoming and outgoing electromagnetic signals are transferred between the portion of the animal body and the current probe by magnetic induction.
    Type: Grant
    Filed: February 4, 2011
    Date of Patent: November 29, 2016
    Assignee: The United States of America as represented by Secretary of the Navy
    Inventor: Daniel W. Tam
  • Patent number: 9000776
    Abstract: A method for estimating the characteristic impedance of a structure comprising the following steps: providing a current probe comprising a magnetic core having an aperture therein and a primary winding wrapped around the core; measuring, with a calibrated vector network analyzer (VNA), the impedance (Zop) of the current probe while in an open configuration wherein nothing but air occupies the aperture and the current probe is isolated from a ground; measuring, with the VNA, the impedance (Zsh) of the current probe while in a short configuration, wherein the current probe is electrically shorted; measuring, with the VNA, the impedance (Zin) of the current probe while the current probe is mounted to the structure such that the structure extends through the aperture; and calculating an estimated characteristic impedance (Z?mast) of the structure according to the following equation: Z?mast=(Zin?Zsh)(Zop?Zsh)/(Zop?Zin).
    Type: Grant
    Filed: December 9, 2010
    Date of Patent: April 7, 2015
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Daniel W. Tam, Randall A. Reeves, John H. Meloling
  • Patent number: 8553817
    Abstract: Systems and methods are disclosed for removing interference in a time-harmonic received composite signal, comprising, sampling an in-band interfering signal from a stationary transmitter at a stationary receiver; sampling a composite signal having the in-band interfering signal and an in-band desired signal from a stationary transmitter at the receiver, deriving at least one of a phase and time difference from the composite signal and sampled in-band interfering signal, applying the derived at least one of phase and time difference to the sampled in-band interfering signal to estimate a synchronized current in-band interfering signal, and generating the un-interfered, in-band desired signal by subtracting the synchronized current in-band interfering signal from a current composite signal.
    Type: Grant
    Filed: March 1, 2011
    Date of Patent: October 8, 2013
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Vincent V. Dinh, Daniel W. Tam
  • Patent number: 8311752
    Abstract: A method for quantifying the effective loss of a mast-clamp-current-probe (MCCP) antenna comprising the following steps: providing a vector network analyzer (VNA) having first and second ports (Ports 1 and 2 respectively); coupling a transmit monopole antenna to Port 1 via a first transmission line; coupling a receive antenna to Port 2 via a second transmission line; determining the S-parameters of the two coupled antennas; calculating the power at the receive antenna (Pr); converting the transmit antenna to the MCCP antenna by shorting the transmit antenna to ground and clamping a current probe around the transmit antenna; determining the S?-parameters of the MCCP antenna and the receive antenna; calculating the power at the receive antenna (Pr?) when coupled to the MCCP antenna; and quantifying the effective loss of the MCCP antenna as the difference Pr?Pr?.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: November 13, 2012
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Daniel W. Tam, Peder M. Hansen, Daniel R. Gaytan
  • Patent number: 6549560
    Abstract: A comb limiter combiner for frequency-hopped communications includes an input signal coupler for coupling to a receiving antenna and distributing the antenna signal to a bank of input bandpass filters. The input bandpass filters have contiguous passbands that comprise the total receiver bandwidth. Each input bandpass filter is connected to a limiter having a threshold substantially equal to the limiting threshold of the receiver. Each limiter is connected to an output bandpass filter similar to the corresponding input bandpass filter to remove out-of-band intermodulation products generated by the limiter. The bank of output bandpass filters is connected to an output signal coupler for coupling to the front end of the receiver.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: April 15, 2003
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Michael A. Maiuzzo, Shing T. Li, John W. Rockway, James H. Schukantz, Daniel W. Tam
  • Patent number: 6211732
    Abstract: The present invention is a Comb linear amplifier combiner (CLAC) apparatus that allows one or more transmitters to transmit through one transmit antenna. The CLAC apparatus passes low powered transmit signals through a bank of bandpass filters. The transmit signals then pass through Class A amplifiers which amplify the transmit signals to the full transmit power. The full transmit power signals then pass through a second bank of bandpass filters. The transmission signals are then transmitted through a single transmission antenna.
    Type: Grant
    Filed: March 12, 1998
    Date of Patent: April 3, 2001
    Assignee: Sentel Corporation
    Inventors: Michael A. Maiuzzo, Shing T. Li, John W. Rockway, James H. Schukantz, Daniel W. Tam