Johns Hopkins University

United States of America As Represented by the Secretary of the Air Force

Syntonics, LLC

Joseph J Suter

Ark L Lew

Binh Q Le

Paul D Schwartz

Jay C Poret

Sharon X Ling

George M Murray

Terry E Phillips

O Manuel Uy

Dennis J Duven

Richard C Benson

Paul A Bernhardt

Bruce G Montgomery

Albert C Sadilek

David D Scott

Thomas R Sanderson

Matthew J Reinhart

James M Cloeren

Jason E Jenkins

An ensemble clock comprises: an input for receiving a reference signal; multiple free-running oscillators each configured to generate a corresponding free-running frequency; an output oscillator configured to generate a controlled frequency having a frequency responsive to a control signal; a differencer unit configured to derive difference measurements indicative of time and frequency-based errors associated with each of (i) the controlled frequency, and (ii) the free-running frequency, relative to the reference signal; and a controller configured to generate the control signal responsive to the difference measurements.

Ensemble oscillator and related methods

An explosive detector that utilizes an array of molecularly imprinted polymer (MIP) coated, bifurcated fiber optic cables to form an image of a target molecule source. Individual sensor fiber assemblies, each with a calibrated airflow, are used to expose the fibers to the target molecule. The detector energizes a dedicated excitation light source for each fiber, while simultaneously reading and processing the intensity of the resulting fluorescence that is indicative of the concentration of the target molecule. Processing electronics precisely controls the excitation current, and measures the detected signal from each narrow band pass filter and photodiode. A computer with display processes the data to form an image of the target molecule source that can be used to identify the source even when low level contamination of the same molecule is present. The detector can be used to detect multiple and/or non-explosive targets by varying the MIP coating.

Apparatus and methods for detecting explosives and other substances

A self-contained, small, lightweight, portable, renewable, modular integrated power source. The power source consists of a recharging means such as solar cells that are laminated onto a rechargeable energy source such as a solid state polymer battery which in turn is laminated onto a substrate containing circuits which manage the polymer battery charging. Charging of the battery can occur via solar energy or, alternatively, via RF coupling using external RF charging equipment or a hand held generator. For added support, the integrated power source is then bonded to an applications housing or structure. This integrated power source can independently power the electronic application. It can also serve as casing or housing by taking the shape of the application enclosure.

Integrated power source layered with thin film rechargeable batteries, charger, and charge-control

An improved RF beacon for use in space/earth communications and positioning determination provides better spectral purity and frequency stability. A power supply provides regulated voltage and control signals to the beacon. Each of two oscillators operate at a slightly different frequency very near the aforementioned 16.7 MHz. The slight difference provides for a frequency selection with respect to the transmitter frequency spectra. The oscillator provides a signal to a plurality of multiplier circuits. The resulting multiplied frequency signals are fed to respective amplifiers. Some of the features of the radio frequency beacon include redundant switchable oscillators, a 1067 MHz signal having data modulation capabilities, the ability to change power levels, improved frequency stability and temperature control characteristics, and a triplexer to optionally combine the three outputs into a single port.

Radio frequency beacon

The invention comprises a means for generating energy while walking or running for storage in a rechargeable battery. One embodiment uses lever arm movement in the heel of a shoe resulting from normal walking or running to generate energy from a built-in generator. The linear or rotational motion of the lever arm engages the circular gear assembly and turns the generator/motor/turbine, thus generating power. The second embodiment uses fluid reservoirs embedded in the shoes. Pressure changes resulting from normal walking or running moves the fluid through a narrow channel connecting two reservoirs, thus generating power by rotating a flywheel and an attached motor/generator/turbine in the middle of the channel. Secondary (rechargeable) batteries are incorporated into the invention either in an integrated form or as an add-on design. Additional features include a digital diagnostic data output, which would serves as a &ldquo;fuel gauge&rdquo; for the secondary batteries, and a smart charging circuit that efficiently controls battery charging from a generator output that varies with step rate and force.

Rechargeable shoe

A microprocessor-based charge control architecture which provides individual battery cell charge control in order to insure an equality of charge among all cells in a rechargeable battery cell array during a single charge cycle. The array is arranged in parallel strings with an identical number of cells in series in each string. The microprocessor controls the amount of charge current in each battery cell via a shunt element for each battery cell, and adjusts the shunt element to bypass a portion of the string current for each battery cell. The invention also permits charge control algorithms to be conveniently updated, provides individual cell coulometry, and autonomously monitors and corrects conditions which can result in battery failure. Any type of rechargeable battery cell and array size can be accommodated. The array size can be set to accommodate the specific voltage and load current requirements of each application.

Topology for individual battery cell charge control in a rechargeable

A pair of interleaved finger-like electrodes are positioned over a pyro-electric sheet of polyvinylidine fluoride and a pair of coatings are formed upon the electrodes having different optical reflectance, and as a result, a light beam energy absorption differential will be produced between the coatings and the resulting change in temperature in the sheet material under the electrodes will cause a voltage to be generated. A differential amplifier is connected across the electrodes to sense this voltage, indicative of the detection of an incoming laser light beam. A light chopper is positioned to interrupt the light beam directed at a portion of the pyro-electric sheet.

Narrow band optical radiation sensor using pyroelectric material

A self-contained, small, lightweight, portable, renewable, modular integrated power source. The power source consists of solar cells that are laminated onto a solid state polymer battery which in turn is laminated onto a substrate containing circuits which manage the polymer battery charging. Charging of the battery can occur via solar energy or, alternatively, via RF coupling using external RF charging equipment or a hand held generator. For added support, the integrated power source is then bonded to an applications housing or structure. This integrated power source can independently power the electronic application. It can also serve as casing or housing by taking the shape of the application enclosure.

Integrated power source

An ionizing radiation detector employs optical fibers as the medium for sensing ionizing radiation emitted by a radioactive source. Light in the infrared region is pumped continuously through an optical fiber located in an area or region where the unintentional discharge of ionizing radiation may be expected, so that such emission is detected the moment it occurs. The source of optical light emits a constant output within a specific wavelength band which changes only when irradiation of the fibers by ionizing radiation causes their internal color centers to change. The output of the fibers is optically coupled to a photomultiplier via a light pipe. A single light source, detector, and associated electronics complete the system. A hand-held unit unique for remote sensing may house these components. Due to safety conditions, these components are located at a point remote from the position liable to become under the influence of the radiation exposure field. Annealing of that portion of the optical fiber influenced by irradiation field restores the exposed portion of the optical fiber to substantially its previous level of sensitivity thereby reversibly establishing the fiber optic for any subsequent exposure. In response to particle bombardment from a cobalt-60 source, the detector reacts to the energy remaining after passage of the beam through a shielding enclosure, thereby giving a reliable indication of the shielding effectiveness of the enclosure.

Growing community of inventors

Ellicott City, MD, United States of America

Joseph J Suter