NAVAL POSTGRADUATE SCHOOL

Technology Transfer Program

U. S. Patents 

 

 

Patent No. US6262942B1
Title: Turbulence-Resolving Coherent Acoustic Sediment Flux Probe Device and Method for Using
Inventor: Timothy Peter Stanton
Date of Issue: July 17 2000
Abstract: This invention describes a new method to estimate the sediment flux in front of a Coherent Acoustic Sediment Probe (CASP) instrument. Also, describer is a newly invented Bistatic Doppler Velocity and Sediment Profiler (BDVSP) device for measuring sediment concentration, sediment velocity, and the resultant sediment transport in a sediment bed, and for the measurement of turbulent stresses and dissipation in the ocean

 

Patent No: US6150848
Title: Two-Phase Dynamic Logic Circuits For Gallium Arsenide Complementary HIGFET Fabrication
Inventor: Douglas Jai Fouts, Khaled Ali Shehata
Date of Issue: Nov 21, 2000
Abstract: A two-phase dynamic logic circuit for complementary GaAs HIGFET fabrication processes has a precharge transistor connected between a precharge voltage source and an output node of the logic circuit. The precharge transistor is controlled by a clock signal such that the output node precharges when the clock signal is low and is isolated from the precharge voltage source when the clock signal is high. An evaluate transistor connected to the output node and an NFET logic block has a first terminal connected to the evaluate transistor such that the evaluate transistor is between the NFET logic block and the output node. A second terminal of the logic block is connected to a voltage source and a data input terminal that is arranged to receive more transistor(s) is arranged to generate a logic value. The evaluated transistor is controlled by the clock signal such that when the clock signal is low, the output node is isolated from the NFET logic black, and when the clock signal is high, the logic value generated by the logic block is allowed to determine the voltage on the output node of logic circuit. A pass-gate is arranged to receive an input signal to the gate(s) of the transistor(s) in the NFET logic block under the control of the clock signal such that the input is allowed to influence the gate voltage of the evaluation transistor when the clock signal is low, but is not allowed to influence the gate voltage of the transistor(s) in the logic block when the clock signal is high

 

 

Patent No: US6047359
Title: Predictive Read Cache Memories For Reducing Primary Cache Miss Latency In Embedded Microprocessor Systems
Inventor: Douglas Jai Fouts
Date of Issue:
Abstract: A predictive read cache reduces primary cache miss latency in a microprocessor system that includes a microprocessor, a main memory and a primary cache memory connected between the main memory and the microprocessor via an instruction address bus, a data address bus and a data bus. The predictive read cache tracks the patters of data read addresses that cause misses in the primary cache and associates the pattern with the specific instruction that generates the pattern of miss addresses. When a pattern has been determined, the address where the next cache data read miss will occur is predicted and sent to memory at a time when the memory is not busy with other transactions. The data at the predicted miss address is then fetched and stored in the predictive read cache. The next time a data read miss occurs in the primary cache, if the miss address matches one of the predicted miss addresses stored in the cache, then the required data is immediately sent to the primary cache from the predictive cache, rather than having to be read out of the much slower main memory.

 

Patent No.: US5996345
Title: Heat Driven Acoustic Power Source Coupled to An Electric Generator
Inventor: Thomas J. Hofler
Date of Issue: December 7, 1999
Abstract: The electricity generating engine has modest efficiency, but may be attrave in remote applications where high-reliability or low-cost or low-environmental noise or solar powering is important. The generator is likely to be most attractive in capacities of a few kW to below 100 W where a tine engine would be impractical using other technologies.

 

Patent No.: US5975462
Title: Integrated Propulsion/Lift/Control System For Aircraft And Ship Applications
Inventor: Max F. Platzer
Date of Issue:
Abstract: A new method for Boundary layer energization and boundary layer propulsion for use on vehicles moving through fluids, which comprises mounting small airfoils parallel or perpendicular to the vehicle’s surface, said airfoils being embedded within the said vehicle’s boundary layer and juxtaposed the surface of said vehicle, said airfoils being approximately the height of the boundary layer thickness and exciting said airfoils into flapping oscillation parallel to the chord plane of said airfoils, said oscillation at a frequency up to 100 cycles per second at an amplitude up to 20 percent of the chord length of said airfoil, whereby flow separation is delayed or suppressed which enables the redesign of said vehicle.

 

Patent No: US5926038
Title: Two-Phase Dynamic Logic Circuits for Gallium Arsenide Complementary HIGFIT Fabrication
Inventor: Douglas Jai Fouts and Khaled Ali Shehata
Date of Issue: July 20, 1999
Abstract: A two-phase dynamic logic circuit for complementary GaAs HIGFET fabrication-processes has a Protegra transistor connected between a precharge voltage source and an output node of the logic circuit. The precharge transistor is controlled by a clock signal such that the output node precharges when the clock signal is low and isolated from the precharge voltage source when the clock signal is high. An evaluate transistor connected to the output node and an NFET logic block has a first terminal connected to the evaluate transistor such that the evaluate transistor is between the NFET logic block and the output node. A second terminal of the logic block is connected to a voltage source and a data input terminal that is arranged to receive data input signals. The NFET logic block includes on or more transistor(s) is arranged to generate a logic value. The evaluate transistor is controlled by the clock signal such that the when the clock signal is low, the output node is isolated from the NFET logic block, and when the clock signal is high, the logic value generated by the logic block is allowed to determine the voltage on the output node of the logic circuit. A pass gate is arranged to receive an input signal and conditionally pass the input signal to the gate(s) of the transistor(s) in the NFET logic block under the control of the clock signal such that the input is allowed to influence the gate voltage of the evaluation transistor when the clock signal is low, but is not allowed to influence the gate voltage of the transistor(s) in the logic block when the clock signal is high.

 

Patent No: US5901556
Title: High-Efficiency Heat-Driven Acoustic Cooling Engine With No Moving Parts
Inventor: Thomas J. Hofler
Date of Issue: May 11, 1999
Abstract: This invention describes a new geometry for a heat driven thermoacoustic me mover (i.e., acoustic motor) and its application to a thermoacoustic refrigerator and to an electricity generator. The heat driven acoustic refrigerator has no moving parts, and is thus extremely reliable, simple, and cheap to manufacture. Unlike previous heat driven acoustic cooling engines, it has good efficiency and compactness and is easy to start, avoiding destructively high temperatures upon start-up. The cooling engine is saleable over an extremely wide range of cooling capacities from integrated circuit and sensor cooling to building air-conditioning. The electricity generating engine has modest efficiency, but may be attractive in remote applications where high-reliability or low- cost or low-environmental noise or solar powering is important. The generator is likely to be most attractive in capacities of a few kW to below 100 W where a tiny engine would be impractical using other technologies.

 

Patent No: US5810716
Title: Articulated Manipulator for Minimally Invasive Surgery (AMMIS)
Inventor: Ranjan Mukherjee and Gangbing Song
Date of Issue: September 22, 1998
Abstract: A mechanism is described to provide dexterity through articulation. The mechanism includes a plurality of concatenated segments for transferring angular rotational motion from a driving device located at its base to the distal end. Each segment in the mechanism acts as both a driven element and a driving element whereby each segment is articulated so that the total articulation of the mechanism is the sum of the articulation motions of each segment.

 

Patent No: US6031879
Title: Wideband Undersampling Digital Receiver
Inventor: Phillip E. Pace, Richard E. Leino and David Styer
Date of Issue: February 29, 2000
Abstract: An antenna receives an analog waveform and an analog signal indicative of the ampli-tude and frequency of the analog waveform. The analog signal is processed in a plurality of parallel digital processing channels each arranged to digitize the analog signal at a corresponding sampling frequency fsi to produce a plurality of digital signals output to produce a corresponding plurality of unique Fourier spectra of length m1=(fsi) (TLi) where TLi is the integration time for the discrete Fourier transform for each digital processing channel. The lengths of the Fourier spectra(mi) are selected to be pairwise relatively prime. The discrete Fourier transform encodes the signals in same form as the symmetrical number system (SNS). A SNS-to-decimal algorithm is then applied to the detected bin values (ai) to determine the numerical value of the frequency f of the analog waveform. The receiver resolves all undersampling ambiguities exactly, thereby relaxing the speed requirements on the digital section of the receiver.

 

Patent No: US5853888
Title: Surface Modification of Synthetic Diamond for Producing Adherent Thick and Thin Film Metallizations for Electronic Packaging
Inventor: Indranath Dutta and Sarath K. Menon
Date of Issue: December 29, 1998
Abstract: An article and a method of making surface modified synthetic diamond substrates at temperatures below 500º C. for electronic packaging applications are described. The article consists of a synthetic diamond substrate, the surface of which has been modified by providing an adherent thin coating of a ceramic (alumina) material so as to enable metallization of synthetic diamond by current industrial methods. The method of surface modification comprises deposition of a thin transition metal layer on the synthetic diamond substrate prior to low temperature reactive vapor deposition of aluminum followed by annealing in an oxygen atmosphere.

 

Patent No: US5953921
Title: Torsionally Resonant Toroidal Thermoacoutic Refrigerator
Inventor: Steven L. Garrett
Date of Issue: September 21, 1999
Abstract: This invention for the production of high amplitude acoustic standing way which can be used for thermoacoustic heat transport purposes, describes the use of a rigid barrier in place of a piston, thereby allowing the suspension of the resonator to be external to the pressurized resonator and allowing an independent choice of motor mechanism, including the use of rotary motors instead of linear motors, while incidently providing a mechanism for circulating external heat transport fluids without requiring additional pumps or heat pipes.

 

Patent No: US5647216
Title: High-Power Thermoacoustic Refrigerator
Inventor: Steven L. Garrett
Date of Issue: July 15, 1997
Abstract: A high-power thermoacoustic refrigerator including a half-wave length resonator, first and second drivers located in housings at first and second ends of said resonator, two pusher cones, a plurality of heat exchangers, a first and second stack, utilizing a compressible gas mixture capable of being tuned to the driver resonance frequency, a halfwave length tube, fluids disposed within said heat exchangers for transferring heat, and voice coils wired 180 degrees out of phase for compressing said compressible fluid into a standing wave oscillating within said resonator.

 

Patent No: US5719762
Title: Method of Controlling a Vehicle to Make a Combination of Arbitrary Translational and Rotational Motions
Inventor: Yutaka John Kanayama
Date of Issue: February 17, 1998
Abstract: A method of controlling a rotary vehicle to navigate a heading using a conation of translational and rotational motions by a plurality of driving-steering wheels controlling the motion in three degrees of freedom for a manned or unmanned vehicle having at least two drive-steering wheels, wherein a drive-steering wheel is a wheel with its heading orientation and driving velocity positively controlled, wherein a global motion is a vehicle trajectory with vehicle orientation from the initial position (with orientation) to a final destination (with orientation), which comprises comparing a global motion selected to the vehicle’s body position and orientation to compute a motion instruction in three degrees of freedom, the acceleration, path of curvature, and rotation rate, collectively known as the motion command then converting the motion command into a translational speed, a translational direction, and a rotational rate and converting the translational speed, the translational direction and the rotational rate into the direction and driving speed for each

 

Patent No: US5763979
Title: Actuation System for the Control of Multiple Shape Memory Alloy Elements
Inventor: Ranjan Mukherjee and Thomas F. Christian
Date of Issue: June 9, 1998
Abstract: An actuation system for the control of multiple shape memory alloy elements is achieved by arranging the shape memory actuators into a matrix comprised of rows and columns which results in approximate a fifty percent reduction in the number of electrical connecting wires. This method of actuation provides the scope for resistance measurements of the shape memory alloy actuators and therefore feedback control of the actuators can be accomplished without additional wires.

 

Patent No: US4577414
Title: Remotely Readable Fiber Optic Compass
Inventor: Albert Migliori, Gregory W. Swift and Steven L. Garrett
Date of Issue: March 25, 1986
Abstract: A remotely readable fiber optic compass. A sheet polarizer is affixed to a magnet rotatably mounted in a compass body, such that the polarizer rotates with the magnet. The optic axis of the sheet polarizer is preferably aligned with the north-south axis of the magnet. A single excitation light beam is divided into four identical beams, two of which are passed through the sheet polarizer and through two fixed polarizing sheets which have their optical axes at right angles to one another. The angle of the compass magnet with respect to a fixed axis of the compass body can be determined by measuring the ratio of the intensities of the two light beams. The remaining ambiguity as to which of the four possible quadrants the magnet is pointing to is resolved by the second pair of light beams, which are passed through the sheet polarizer at positions which are transected by two semicircular opaque strips formed on the sheet polarizer. The incoming excitation beam and the four return beams are communicated by means of optical fibers, giving a remotely readable compass which has no electrical parts.

 

Patent No: US5617092
Title: High Resolution Encoding Circuit and Process for Analog to Digital Conversion
Inventor: Phillip E. Pace
Date of Issue: April 1, 1997
Abstract: An analog-to-digital converter in which an analog input signal is folded by a plurality of folding circuits whose moduli, and hence half folding periods, are mutually prime with respect to one another. Each folding circuit has an associated comparator ladder having one less comparator than the modulus of the folding circuit. The collective output of the ladders, i.e., the states of the comparators in the ladders, uniquely corresponds to input signal magnitude over a dynamic range equal to the folding circuits’ moduli, permitting a greater dynamic range for the converter for the number of comparators used.

 

Patent No: US5369485
Title: Fiber Optic Accelerometer with Centrally Supported Flexural Disk
Inventor: Thomas J. Hofler, David A. Brown and Steven L. Garrett
Date of Issue: November 29, 1994
Abstract: An accelerometer or seiesmometer has an elastic disk bearing a mass distributed peripherally around the disk. The disk is supported for flexure and for isolation from mounting strain by a stob centrally through the disk. The accelerometer or seismometer has a pair of flat spirals of optical fiber, each spiral being fixedly attached to a corresponding disk side so that disk flexure lengthens a spiral on one disk side and shortens a spiral on an oppositely facing disk side and so that temperature differences between the spirals are minimized. The pair of spirals are connected as legs of a fiber optic interferometer so that the interferometer provides an output corresponding to the flexure. Several of the disks and associated pairs of spirals may be coaxially mounted to provide increased sensitivity.

 

Patent No: US5546797
Title: Constant-Depth Scratch Test for the Quantification of Interfacial Shear Strength at Film-Substrate Interfaces
Inventor: Indranath Dutta and David P. Lascurain
Date of Issue: August 20, 1996
Abstract: A Constant-Depth Scratch Test (CDST) technique to quantitatively determine the shear strength of interfaces between thin metallic or non-metallic films and metal or ceramic substrates is revealed. The test overcomes two problems associated with other types of scratch tests, namely the instrumental complexity required for real-time detection of interfacial strength. These problems are circumvented by maintaining a constant depth during scratching through the coating and the substrate, monitoring the horizontal and vertical forces to sustain the constant depth scratch, and finally by using a model to analyze the test results to quantify the interfacial shear strength. Unlike other scratch tests, this test is capable of measuring interfacial shear strength as a function of position on the film-substrate sample.

 

Patent No: US5456082
Title: Pin Stack Array for Thermoacoustic Energy Conversion
Inventor: Robert M. Keolian and Gregory W. Swift
Date of Issue: October 10, 1995
Abstract: A thermoacoustic stack for connecting two heat exchangers in a thermoacoustic energy converter provides a convex fluid-solid interface in a plane perpendicular to an axis for acoustic oscillation of fluid between the two heat exchangers. The convex surfaces increase the ratio of the fluid volume in the effective thermoacoustic volume that is displaced from the convex surface to the fluid volume that is adjacent to the surface within which viscous energy losses occur. Increasing the volume ratio results in an increase in the ratio of transferred thermal energy to viscous energy losses, with a concomitant increase in operating efficiency of the thermoacoustic converter. The convex surfaces may be easily provided by a pin array having elements arranged parallel to the direction of acoustic oscillations and with effective radial dimensions much smaller than the thicknesses of the viscous energy loss and thermoacuostic energy transfer volumes.

 

Patent No: US5454048
Title: Apparatus for Multiplexed Imaging Using Optically-Generated Kronecker Products
Inventor: David S. Davis
Date of Issue: September 26, 1995
Abstract: A new type of fully-multiplexed imaging device is described for use at wavelengths where efficient focal plane array detectors are unavailable. It shares some properties in common with the familiar technique of cycle-redundancy (i.e., Hadamard transform) imaging, but many of its features and capabilities are unique. Some of these characteristics are, first, the new approach employs image encoding masks that are both transmitting and reflecting, thereby increasing optical efficiency, and second, the technique requires only 2.sqroot.N encoding masks to image a field of N pixels, a dramatically smaller number than that needed (~2N) by traditional methods. Dual complementary inputs are used for first-order passive rejection of radiation background interference. The resulting image spatial resolutions along two coordinate directions are completely independent of each other. The measured image is formed by a convergent tiling of the image plane, quite unlike conventional raster scanning. In principle, the technique is capable of versatile adaptation to a wide variety of imaging and target discrimination tasks in infrared and microwave remote sensing.

 

Patent No: US5313266
Title: Demodulators for Optical Fiber Interferometers with [3X3] Outputs
Inventor: Robert M. Keolian, Steven L. Garrett and Charles B. Cameron
Date of Issue: May 17, 1994
Abstract: A highly sensitive optical fiber interferometer sensor comprising a laser light source, a [2X2] optical fiber coupler to split the beam in two, a differential transducer which converts a signal of interest into optical phase shift in the laser light transmitted through the two optical fibers in the interferometer and a [3X3] optical fiber complex which recombines the two beams, producing interference which can be electronically detected. The use of the [3X3] coupler permits Passive Homodyne demodulation of the phase-modulated signals provided by the interferometer without feedback control or modulation of the laser itself and without requiring the use of electronics within the interferometer.

 

Patent No: US5212670
Title: Flextensional Hydrophone
Inventor: David A. Brown
Date of Issue: May 18, 1993
Abstract: An omnidirectional hydrophone having an elastic shell in the form of an ote ellipsoid of revolution having the ratio of its major axis to its minor axis greater than about sq root.(2-.nu.) where .nu. is Poisson’s ratio of the shell material, wherein the circular circumference of the shell (at different circular parallels of latitude) undergoes strains of opposite sign when the shell is subjected to a pressure change. The differential strains are advantageously measured by an optical fiber interferometer having one leg wound about the equatorial circumference of the shell and another leg spirally wound near one or both of the poles.

 

Patent No: US5317929
Title: Fiber Optic Flexural Disk Accelerometer
Inventor: David a. Brown, Steven L. Garrett and Thomas J. Hofler
Date of Issue: June 7, 1994
Abstract: An accelerometer or seismometer has a pair of flat spirals of optical fiber and has one or more elastic disks bearing a mass and supported for flexure. Each spiral is fixedly attached to a corresponding disk side so that disk flexure lengthens a spiral on one disk side and shortens a spiral on an oppositely facing disk side, the spirals being connected as legs of a fiber optic interferometer so that the interferometer provides an output corresponding to the flexure. A pair of the disks may be mounted oppositely of a sealed body with a pair of the spirals arranged to minimize the effect of pressure changes on the sensor, and a pair of the spirals may be mounted oppositely of a thermally conducting disk to minimize temperature differences between the spirals. The mass may be centrally mounted on a disk with the disk peripherally supported, or the mass may be distributed around the disk periphery with the disk centrally supported for isolation from mounting strain. Several of the disks may be coaxially mounted to provide increased sensivity.

 

Patent No: US 5073711
Title: Fiber-Optic Remote Angular Position Sensor Including a Polarization Track
Inventor: Michael R. Brininstool, Jeffrey T. Newmaster and Steven L. Garrett
Date of Issue: December 17, 1991
Abstract: A sensor for remotely detecting an angular position of a shaft rotatable within a frame includes: first means for generating collimated first, second, third, and polarized optical beams; second means positioned proximate to the first means for receiving and combining the first, second, third, and polarized optical beams into a composite optical beam having an intensity; and a code wheel fixedly mounted to the shaft and interposed between the first and second means. The code wheel includes first, second, and third channel mask patterns and a first polarizing filter positioned to transect the first, second, third, and polarized optical beams, respectively. Interaction between the code wheel and the light beams results in the composite light beam being encoded such that the angular position of the wheel is functionally related to the intensity of the composite optical beam. The sensor further includes third means operably coupled to receive the composite optical beam for providing an output corresponding to the angular position of the code wheel.

 

Patent No: US 5042157
Title: Fiber Optic Angular Orientation Sensor Digital Serial Encoding
Inventor: Steven L. Garrett, Michael R. Brininstool, Jeffrey T. Newmaster and Thomas Hofler
Date of Issue: August 27, 1991
Abstract: A sensor provides remote angular orientation sensing. A rotational signal transmitted To a rotatable input shaft mounted in an encoder body causes the shaft to rotate. Light signals are transmitted through a digital code wheel mounted to the shaft. As the code wheel and shaft rotate, the light signals passing through the code wheel are super-imposed with light pulses corresponding to incremental and directional changes of angular position of the code wheel with respect to the encoder body. The light signals are propagated through an optical fiber to a remote combination digital and analog circuit which converts them into a digital representation of the angular position of the code wheel.

 

Patent No: US 4959539
Title: Flexural Disk Fiber Optic Hydrophone
Inventor: Thomas J. Hofler and Steven L. Garrett
Date of Issue: September 25, 1990
Abstract: A hydrophone or other acoustic vibration sensing apparatus having a disk circumferentially supported for flexure induced by acoustic vibrations and wound on each side with a flat spiral of optical fiber fixedly attached to the disk side so that flexure of the disk due to the vibrations lengthens the spiral on one side and shortens the spiral on the other side. The spirals are connected as two legs of a fiber optic interferometer to provide an output corresponding to the vibrations while canceling errors due to pressure and temperature effects common to the legs. A pair of the disks and associated optical fiber spirals may be mounted on opposite ends of a body with the outer spirals connected as one interferometer leg and the inner spirals as another leg to cancel differences in the lengths of the legs due to acceleration induced flexure of the disks and to provide double the sensitivity to pressure differential of a single disk.

 

Patent No: US4958072
Title: Remote Fiber Optic Angular-Orientation Sensor Using Phase Detection of Two Orthogonal Oscillating Polarization Vectors
Inventor: Thomas Hofler, Michale R. Brininstool, Jeffrey T. Newmaster and Steven L. Garrett
Date of Issue: September 18, 1990
Abstract: A method of remotely detecting the angular position of a rotatable code wheel is provided by generating two sine wave modulated light beams which are orthogonally polarized with respect to each other. The beams are combined and then directed through a polarization filter mounted on the code wheel. The combined beam incurs a phase shift with respect to a reference signal which depends upon the position of the code wheel. The combined polarized beam provides angular position resolution between zero and ninety degrees, but lacks quadrant resolution. Two other light beams are directed to a two channel digital mask pattern imprinted on the code wheel. The mask pattern encodes these latter beams with "on" or "off" pulses to provide quadrant resolution. The beams are converted to digital electric signals which are received by a programmable read only memory (PROM). The PROM provides an output corresponding to the angular position of the code wheel to a display.

 

Patent No: US 4951271
Title: Flextensional Hydrophone
Inventor: Steven L. Garrett and Donald A. Danielson
Date of Issue: August 21, 1990
Abstract: An omnidirectional hydrophone having an elastic shell which is spheroidal so that the circumference of the shell about different axes changes differentially when the shell is subjected to pressure variations. The differences in circumference are advantageously measured by an optical fiber interferometer having one leg wound about the equatorial circumference of the shell and another leg wound about its meridional circumference. The shell may be an oblate spheroid having the ratio of its major axis to its minor axis greater than about (2-v)¼, where v is Poisson’s ratio of the shell material, so that the shell narrows along one axis and widens along the other when the shell is subjected to a pressure change.

 

Patent No: US 4893930
Title: Multiple Axis, Fiber Optic Interferometric Seismic Sensor
Inventor: Steven L. Garrett and David L. Gardner
Date of Issue: January 16, 1990
Abstract: A mechanical vibration transducer includes a seismic mass is supported by a plurality of cylindrical silicone rubber mandrels. Each mandrel is wound with a length of optical fiber which has a reflective end and a transmissive end. A case surrounds the assemblage and is connected to the supports. When the case is displaced, the supports change the diameter in response to the relative motion between the seismic mass and the case. This change in diameter is translated to a change in length of the optical fiber. By using the fibers as arms of a michelson interferometer, a sensitive instrument responsive to displacing vibrations is obtained. This instrument is energized entirely by light transmitted through optical fiber waveguides and whose information is transmitted to the observor using only light-waves in optical fibers.