Patents Represented by Attorney Ronald F. Sandler
  • Patent number: 6377202
    Abstract: An icing hazard avoidance system and method utilizes a forward-looking, single frequency, dual-polarization pulse radar system as well as temperature sensing means to determine if supercooled liquid water (SLW) drops are present in an aircraft's flight path. A processor determines the ratio of co-polarized and cross-polarized returns. This ratio and the temperature of the atmosphere indicate if SLW drops exists. If an icing hazard is determined, an indicator in the cockpit of the aircraft alerts pilots so that avoidance measures may be taken.
    Type: Grant
    Filed: March 24, 2000
    Date of Patent: April 23, 2002
    Assignees: The United States of America as represented by the Secretary of Commerce, University Technology Corporation
    Inventors: Robert A. Kropfli, Roger F. Reinking, Bruce W. Bartram, Sergey Y. Matrosov, Brooks E. Martner
  • Patent number: 5399993
    Abstract: High input impedance amplifiers are provided which reduce the input impedance solely to a capacitive reactance, or, in a somewhat more complex design, provides an extremely high essentially infinite, capacitive reactance. In one embodiment, where the input impedance is reduced in essence, to solely a capacitive reactance, an operational amplifier in a follower configuration is driven at its non-inverting input and a resistor with a predetermined magnitude is connected between the inverting and non-inverting inputs. A second embodiment eliminates the capacitance from the input by adding a second stage to the first embodiment. The second stage is a second operational amplifier in a non-inverting gain-stage configuration where the output of the first follower stage drives the non-inverting input of the second stage and the output of the second stage is fed back to the non-inverting input of the first stage through a capacitor of a predetermined magnitude.
    Type: Grant
    Filed: August 26, 1993
    Date of Patent: March 21, 1995
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Leonard L. Kleinberg
  • Patent number: 5363288
    Abstract: A high voltage power supply in a dc--dc converter configuration includes a pre-regulator which filters and regulates the dc input and drives an oscillator which applies, in turn, a low voltage ac signal to the low side of a step-up high voltage transformer. The high voltage side of the transformer drives a voltage multiplier which provides a stepped up dc voltage to an output filter. The output voltage is sensed by a feedback network which then controls a regulator. Both the input and output of the regulator are on the high voltage side, avoiding isolation problems. The regulator furnishes a portion of the drive to the voltage multiplier, avoiding having a regulator in series with the load with its attendant, relatively high power losses. This power supply is highly regulated, has low power consumption, a low parts count and may be manufactured at low cost. The power supply has a programmability feature that allows for the selection of a large range of output voltages.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: November 8, 1994
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Karen D. Castell, Arthur P. Ruitberg
  • Patent number: 5311198
    Abstract: An antenna, which may be a search coil, is connected to an operational amplifier circuit which provides negative impedances, each of which is in the order of magnitude of the positive impedances which characterize the antenna. The antenna is connected to the inverting input of the operational amplifier, a resistor is connected between the inverting input and the output of the operational amplifier, a capacitor-resistor network, in parallel, is connected between the output and the noninverting input of the operational amplifier, and a resistor is connected from the noninverting input and the circuit common. While this circuit provides a negative resistance and a negative inductance, in series, which appear, looking into the noninverting input of the operational amplifier, in parallel with the antenna, these negative impedances appear in a series loop with the antenna positive impedances, so as to algebraically add.
    Type: Grant
    Filed: August 23, 1990
    Date of Patent: May 10, 1994
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: John F. Sutton
  • Patent number: 5296866
    Abstract: An antenna, which may be a search coil, connected to an active circuit which provides negative impedances, each of which is of the order of magnitude of the positive impedances which characterize this active antenna. In one embodiment, one coil terminal is connected to an amplifier which drives a voltage-controlled current source that, in turn, drives a feedback coil which is coupled to the original search coil. In another embodiment that additionally exhibits an advantageous signal-to-noise characteristic, both terminals of the search coil are connected to a differential amplifier that, in turn, provides the control voltage for a current source, which, as in the first embodiment, drives the feedback winding. The feedback coil is wound to provide positive feedback by additive superposition of both coil fields.The positive feedback provided by the feedback current lowers the antenna impedance which, in turn, increases the effective area of the antenna.
    Type: Grant
    Filed: July 29, 1991
    Date of Patent: March 22, 1994
    Assignee: The United States of America as represented by the Adminsitrator of the National Aeronautics and Space Administration
    Inventor: John F. Sutton
  • Patent number: 5184241
    Abstract: A laser transmitting and receiving system includes doppler compensation for large doppler shifts in frequency caused by relative motion between a collocated transceiver and a target or relative motion between separated transmitters and receivers. The system includes a tunable laser, a dithered laser optical frequency standard, and a computer for calculating the estimated doppler shift at a given time using platform navigation and attitude control inputs as well as inputs relating to pointing data controlling the direction of transmission. The frequency standard and the computer output are employed to develop a doppler compensation signal which may be used to shift the frequency of the laser transmitter or shift the bandpass of a laser receiver filter. The doppler compensation is provided by a feedback loop which may include r.f. components, a timing trigger from the computer, or wavemeters.
    Type: Grant
    Filed: June 21, 1989
    Date of Patent: February 2, 1993
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics & Space Admininstration
    Inventor: Geary K. Schwemmer
  • Patent number: 5041881
    Abstract: A Schottky diode for millimeter and submillimeter wave applications is comprised of a multi-layered structure including active layers of gallium arsenide on a semi-insulating gallium arsenide substrate with first and second insulating layers of silicon dioxide on the active layers of gallium arsenide. An ohmic contact pad lays on the silicon dioxide layers. An anode is formed in a window which is in and through the silicon dioxide layers. An elongated contact finger extends from the pad to the anode and a trench, preferably a transverse channel or trench of predetermined width, is formed in the active layers of the diode structure under the contact finger. The channel extends through the active layers to or substantially to the interface of the semi-insulating gallium arsenide substrate and the adjacent gallium arsenide layer which constitutes a buffer layer.
    Type: Grant
    Filed: March 6, 1989
    Date of Patent: August 20, 1991
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: William L. Bishop, Kathleen A. McLeod, Robert J. Mattauch
  • Patent number: 5029216
    Abstract: A multi-channel electronic visual aid device which is able to signal to the user whether sound is coming from the left or right, front or back, or both. For the plurality of channels, which may operate in pairs, the sound is picked up by a respective microphone and amplified and rectified into a DC voltage. The DC voltage is next fed to an analog to digital converter and then to a digital encoder. The binary code from the encoder is coupled into a logic circuit where the binary code is decoded to provide a plurality of output levels which are used to drive an indicator which, in turn, provides a visual indication of the sound level received. The binary codes for each pair of channels are also fed into a digital comparator.
    Type: Grant
    Filed: June 9, 1989
    Date of Patent: July 2, 1991
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics & Space Administration
    Inventors: Murzban D. Jhabvala, Hung C. Lin
  • Patent number: 5021729
    Abstract: A differential, voltage-controlled current source, employing operational amplifiers as the active elements, provides an essentially symmetrical, differential, high impedance drive to a load, the drive being isolated from any circuit common or system ground. Because of the "floating" differential drive and the identical source impedances of the two outputs, errors from common mode voltages are eliminated.
    Type: Grant
    Filed: October 6, 1989
    Date of Patent: June 4, 1991
    Assignee: The United States of America as represented by the Administrator of the Administration National Aeronautics and Space
    Inventor: John F. Sutton
  • Patent number: 5015963
    Abstract: A synchronous demodulator includes a switch which is operated in synchronism with an incoming periodic signal and both divides and applies that signal to two signal channels. The two channels each include a network for computing and holding, for a predetermined length of time, the average signal value on that channel and applies those values, in the form of two other signals, to the inputs of a diffferential amplifier. The networks may be R-C networks. The output of the differential amplifier may or may not form the output of the synchronous detector and may or may not be filtered. The output will not include a periodic signal due to the presence of a dc offset. Additionally, the output will not contain any substantial ripple due to periodic components in the input signal.
    Type: Grant
    Filed: September 29, 1989
    Date of Patent: May 14, 1991
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: John F. Sutton
  • Patent number: 5014340
    Abstract: A transmitter generates three signals for sequential transmission. These signals are an unmodulated r.f. carrier, an r.f. carrier amplitude modulated by a first audio frequency waveform and an r.f. carrier amplitude modulated by a second audio frequency waveform which is distinguishable from the first and which may be employed as a means for identifying a particular transmitter. The composite, sequentially transmitted signal may be varied in terms of the individual signal transmission sequence, the duration of the individual signals, overall composite signal repetition rate and the frequency of the second audio waveform. Various combinations of signal variations may be employed to transmit different information.
    Type: Grant
    Filed: September 9, 1988
    Date of Patent: May 7, 1991
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Paul E. Wren
  • Patent number: 4973914
    Abstract: A digitized synchronous demodulator is constructed entirely of digital components including timing logic, an accumulator, and means to digitally filter the digital output signal. Indirectly, it accepts, at its input, periodic analog signals which are converted to digital signals by traditional analog-to-digital conversion techniques. Broadly, the input digital signals are summed to one of two registers within an accumulator, based on the phase of the input signal and mediated by timing logic. At the end of a predetermined number of cycles of the inputted periodic signals, the contents of the register that accumulated samples from the negative half cycle is subtracted from the accumulated samples from the positive half cycle. The resulting difference is an accurate measurement of the narrow band amplitude of the periodic input signal during the measurement period.
    Type: Grant
    Filed: October 10, 1989
    Date of Patent: November 27, 1990
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Christopher E. Woodhouse
  • Patent number: 4946421
    Abstract: A cable-compliant robotic joint includes two "U" configuration cross-section brackets with their "U" cross-sections lying in different planes, one of the brackets being connected to a robot arm and the other to a tool. Additional angle brackets are displaced from the other brackets at corners of the robotic joint. All the brackets are connected by cable segments which lie in one or more planes which are perpendicular to the direction of tool travel as it approaches a work object. The compliance of the joint is determined by the cable segment characteristics, such as their length, material, angle, stranding, pre-twisting and pre-stressing.
    Type: Grant
    Filed: May 13, 1988
    Date of Patent: August 7, 1990
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: James J. Kerley, Jr.
  • Patent number: 4902574
    Abstract: Fluoroepoxy compounds are made by reacting a fluoroepoxy resin with an effective curing agent, such as an adduct amine, and, while the compound is sufficiently liquid to wet a fluoroplastic surface, it may be applied to a fluoroplastic adherend, such as a Teflon, to be employed as an adhesive, to form various fluoroplastic products, without requiring any surface treatment of the adherend. The compounds are intentionally formulated with high fluorine contents, normally above 46% by weight, preferably for bonding fluoroplastics with a high F-content, above 55% by weight.
    Type: Grant
    Filed: October 14, 1987
    Date of Patent: February 20, 1990
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Sheng Y. Lee
  • Patent number: 4888595
    Abstract: An encoded information transmitter which transmits a radio frequency carrier that is amplitude modulated by a constant frequency waveform and thereafter amplitude modulated by a predetermined encoded waveform, the constant frequency waveform modulated carrier constituting an acquisition signal and the encoded waveform modulated carrier constituting an information bearing signal, the acquisition signal providing enhanced signal acquisition and interference rejection favoring the information bearing signal. One specific application for this transmitter is as a distress transmitter where a conventional, legislated audio tone modulated signal is transmitted followed first by the acquisition signal and then the information bearing signal, the information bearing signal being encoded with, among other things, vehicle identification data.
    Type: Grant
    Filed: February 29, 1988
    Date of Patent: December 19, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Morton L. Friedman
  • Patent number: 4883116
    Abstract: A wick for use in a capillary loop pump heat pipe. The wick material is an essentially uniformly porous, permeable, open-cell, silicon dioxide/aluminum oxide inorganic ceramic foam having a silica fiber to alumina fiber ratio, by weight, of about 78 to 22, respectively, a density of 6 lbs/ft.sup.3, and an average pore size of less than 5 microns. A representative material having these characteristics is Lockheed Missiles and Space Company, Inc. HTP 6-22. This material is fully compatible with the FREONs and anhydrous ammonia and allows for the use of these very efficient working fluids, and others, in capillary loops.
    Type: Grant
    Filed: January 31, 1989
    Date of Patent: November 28, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Benjamin Seidenberg, Theodore D. Swanson
  • Patent number: 4873498
    Abstract: A reflection oscillator is provided which employs an active device operated in its roll-off region and two resonant circuits. For an oscillator employing a bipolar transistor, the emitter is connected to a series resonant capacitor-crystal network and the base is connected to an L-C tank circuit with the transistor being operated in the roll-off region of its gain versus frequency curve. This will provide a very high frequency of operation with a relatively inexpensive, low frequency, active device. These oscillators are easily tuned, stable, and require little d.c. power.
    Type: Grant
    Filed: December 30, 1988
    Date of Patent: October 10, 1989
    Assignee: The United States of America as represented by the Administrator, National Aeronautics and Space Administration
    Inventor: Leonard L. Kleinberg
  • Patent number: 4862114
    Abstract: A simple and inexpensive crystal oscillator is provided which employs negative voltage gain, single pole response amplifiers. The amplifiers may include such configurations as gate inverters, operational amplifiers and conventional bipolar transistor amplifiers, all of which operate at a frequency which is on the roll-off portion of their gain versus frequency curve. Several amplifier feedback circuit variations are employed to set desired bias levels and to allow the oscillator to operate at the crystal's fundamental frequency or at an overtone of the fundamental frequency. The oscillator is made less expensive than comparable oscillators by employing relatively low frequency amplifiers and operating them at roll-off, at frequencies beyond which they are customarily used. Simplicity is provided because operation at roll-off eliminates components ordinarily required in similar circuits to provide sufficient phase-shift in the feedback circuitry for oscillation to occur.
    Type: Grant
    Filed: June 23, 1988
    Date of Patent: August 29, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Leonard L. Kleinberg
  • Patent number: 4843123
    Abstract: Thermosetting fluoropolymer foams are made by mixing fluid form thermosetting fluoropolymer components having a substantial fluorine content, placing the mixture in a pressure tight chamber, filling the chamber with a gas, at relatively low pressure, that is unreactive with the fluoropolymer components, allowing the mixture to gel, removing the gelled fluoropolymer from the chamber and thereafter heating the fluoropolymer at a relatively low temperature to simultaneously cure and foam the fluoropolymer. The resulting fluoropolymer product is closed celled with the cells storing the gas employed for foaming. The fluoropolymer resins employed may be any thermosetting fluoropolymer including fluoroepoxies, fluoropolyurethanes and fluoroacrylates.
    Type: Grant
    Filed: March 4, 1988
    Date of Patent: June 27, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Sheng Y. Lee
  • Patent number: 4843440
    Abstract: Electrodes of a high power, microwave field effect transistor are substantially matched to external input and output networks. The field effect transistor includes a metal ground plane layer, a dielectric layer on the ground plane layer, a gallium arsenide active region on the dielectric layer, and substantially coplanar spaced source, gate and drain electrodes having active segments covering the active region. The active segment of the gate electrode is located between edges of the active segments of the source and drain electrodes. The gate and drain electrodes include inactive pads remote from the active segments thereof. The pads are connected directly to the input and output networks. The source electrode is connected to the ground plane layer.
    Type: Grant
    Filed: November 29, 1984
    Date of Patent: June 27, 1989
    Assignee: United States of America as represented by the Administrator of the National Aeronautics & Space Administration
    Inventor: Ho-Chung Huang