USA As Represented by Secretary of the Navy

Sentel Corporation

Daniel W Tam

James H Schukantz, Jr

John W Rockway

Peder M Hansen

Michael A Maiuzzo

Aldo Monges

Shing Ted Li

Marcus L Maurer

Randall A Reeves

Jack Y Dea

John Harold Meloling

Robert S Abramo

James C Logan

David Earl Hurdsman

Vincent V Dinh

Daniel R Gaytan

Jodi McGee

Chris Dilay

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.

Current probe fed dipole array on dielectric water bottle with brine water loading

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.

Animal body antenna

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 (Z) 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 (Z) of the current probe while in a short configuration, wherein the current probe is electrically shorted; measuring, with the VNA, the impedance (Z) 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') of the structure according to the following equation: Z&#x2032;=(Z&#x2212;Z)(Z&#x2212;Z)/(Z&#x2212;Z).

Structure characteristic impedance estimator using current probe

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.

Method and apparatus for shipboard co-site in-band desired signal extraction

Methods for remote detection of humans can include the step of transmitting vertically polarized electromagnetic signals into an area of interest (AOI) when no humans are present. A first time domain measurement of return response signal energy from the AOI can be accomplished to establish a background signal. A second time domain measurement of response signal energy from the AOI can be made when at least one human is present, to establish a background-plus-human signal. The two signals can be subtracted to yield a reference time domain human signal. The electromagnetic signal is periodically re-transmitted. The background subtracted from subsequent response energy, and the result compared to the reference time domain human signal. A visual or audible indication occurs when the resulting signal matches the reference signal. Fast Fourier Transforms (FFT) of the time domain signals can be used to yield frequency responses, which can be monitored.

Remote human presence detection system

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 (P); 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 (P&#x2032;) when coupled to the MCCP antenna; and quantifying the effective loss of the MCCP antenna as the difference P&#x2212;P&#x2032;.

Method and apparatus to quantify mast clamp current probe effective loss on pole-mast antenna

Methods and systems for detection of an electric field generated by the human/animal body can include providing a passive antenna system for detecting changes in the ambient electric field due to interaction of the ambient with the charges generated by the human/animal body, and a high impedance sensor that is fixed to the encapsulated wire antenna. The result is a passive human/animal detection system without any moving parts. The antenna can be an encapsulated wire, and the wire length can be chosen according the desired application. For systems that are intended to detect the presence of a human being or animal, the encapsulated wire can have a length of one hundred feet or more, and a grid of wires can be used for detection within an Area of Interest (AOI).

Human presence electric field sensor

An apparatus for remotely detecting metal objects carried by a person includes an antenna and a signal generator coupled to the antenna operable to cause the antenna to emit a first electromagnetic signal to the person at a frequency that is known to be resonant with the human body. The apparatus further includes a data capture device operable to capture response signal energy received by the antenna, the response signal energy being provided from the person in response to the first electromagnetic signal. Processing circuitry for the apparatus is operable to determine whether the response signal energy is indicative whether or not the person is carrying an appreciable amount of metal, based on reference response templates for persons that are known to be metal-free.

Remote detection of covertly carried metal objects

A multi-band antenna comprising a conductive structure and a plurality of current probes coupled around the conductive structure. Each current probe is designed to receive and transmit in a substantially different frequency band than the other current probes. The current probes are positioned on the conductive structure so as to effectively create a plurality of transmit/receive antennas such that each respective antenna has a voltage standing wave ratio (VSWR) of less than or equal to approximately 3:1 for a given range within each respective frequency band.

Multiband current probe fed antenna

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.

Comb limiter combiner for frequency-hopped communications

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.

Growing community of inventors

San Diego, CA, United States of America

Daniel W Tam