Patents Examined by T. H. Tubbesing
  • Patent number: 5237328
    Abstract: This invention concerns a system to protect active or passive electronic equipment from radar detection. In other words equipment which transmits or receives microwave radiation, for example a radar or telecommunications transmitter or receiver.For this purpose, the transmitting surface of the equipment is covered by a device which can be controlled to apply a phase shift of approximately .pi./2 to the incident wave; this enables a microwave incident on the equipment to be modulated in phase. The frequency spectrum of the wave reflected by the equipment is modified and spread thus making it more difficult to detect the equipment. To avoid any perturbation of the operation of the equipment, an inverse modulation is applied to signals transmitted and/or received by the equipment itself.
    Type: Grant
    Filed: December 27, 1991
    Date of Patent: August 17, 1993
    Assignee: Thomson-CSF Radant
    Inventors: Jacques Dorey, Claude Chekroun
  • Patent number: 5235336
    Abstract: In a Traffic Alert and Collision Avoidance System on an aircraft having a plurality of antennas, an optimal bearing value is obtained for each target aircraft by generating a target data block for each response to an interrogation, each target data block including a measured bearing value and an associated priority code. A priority code is assigned based on the antenna receiving the information, and the number of valid bearing measurements used to determine a measured bearing value for the reply. If more than one target data block is obtained in a surveillance period, one target data block is retained based on predetermined criteria. The measured bearing value of all the target data blocks having the same, highest priority code are selected or combined, the result being saved in the target data block. The priority codes are then used to select the proper reply bearing measurement, the bearing track update filtering parameters, and to aid in the reply qualification for bearing track initialization.
    Type: Grant
    Filed: September 27, 1991
    Date of Patent: August 10, 1993
    Assignee: Honeywell Inc.
    Inventors: Patricia K. Sturm, Gregory T. Stayton
  • Patent number: 5235337
    Abstract: An improved search and rescue transponder having an improved housing assembly that permits the device to be turned on or off by rotating one segment of the housing relative to the other for ease of use even with heavy or bulky gloves. In addition, the housing assembly exterior surface includes a plurality of longitudinal ridges for ease in gripping. The housing assembly includes an upper housing and lower housing joined by a retaining ring and O-ring seal, eliminating the need for fasteners for manufacturing efficiency. The lower housing includes quick disconnect that attaches to a mounting disk affixed to a ship or life raft. The mounting disk includes a plurality of resilient fingers which act in conjunction with cam surfaces on the flange of the lower housing, which when rotated together allow for a quick disconnect.
    Type: Grant
    Filed: April 7, 1992
    Date of Patent: August 10, 1993
    Assignee: ACR Electronics, Inc.
    Inventors: Mark S. Clark, Edward I. Nelson
  • Patent number: 5231402
    Abstract: To detect and classify a helicopter as a target by means of a radar system equipped with a Doppler filter bank, an initial determination is made as to whether the threshold value has been exceeded in a substantial number of the individual filters of the Doppler filter bank, and if so, the width of that amplitude band delimited by the highest and lowest amplitudes of the filter output signals is determined and a decision regarding the presence of a helicopter target is derived from the width of the amplitude band.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: July 27, 1993
    Assignee: Telefunken Systemtechnik GmbH
    Inventors: Albrecht Ludloff, Manfred Minker, Frank Hagedorn
  • Patent number: 5229773
    Abstract: An absorbing assembly for absorbing electromagnetic radiation in the range 10 MHz to 100 GHz comprises a lossy dielectric material and chiral elements disposed outside the lossy dielectric. The chiral elements may be springs, Mobius bands, irregular tetrahedra, tapering helical springs or handed non-planar forks. The lossy dielectric material may be in the form of a shaped structure e.g. for use in an anechoic chamber.
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: July 20, 1993
    Assignee: Grace N.V.
    Inventors: Jan M. A. Dauwen, August T. Timmerman, Michel A. C. Van Craenendonck, Hugo F. Pues
  • Patent number: 5229776
    Abstract: A method for obtaining the far field pattern of a phased array MLS antenna using measurements by a monitor located in the near field of the MLS antenna. The near field pattern differs from the far field pattern because of the presence of phase error terms in the measured near field pattern. The method comprises computing the Fourier transform of the complex conjugates of the phase error term of the near field pattern and convolving that transform with the measured near field pattern to obtain the far field pattern.
    Type: Grant
    Filed: June 11, 1992
    Date of Patent: July 20, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Robert J. Kelly, Edward F. C. LaBerge
  • Patent number: 5229775
    Abstract: A digital pulse compression apparatus comprises a plurality of doppler correction circuits for carrying out doppler correction in the time domain or the frequency domain and for carrying out pulse compression, and a maximum amplitude selecting means for selecting and outputting the maximum amplitude signal out of the compressed signals obtained from the doppler correction circuit at the rate of range bin period. The present invention can supply a pulse compression apparatus having a stable compression performance, even if a doppler frequency of the input signal is not known.
    Type: Grant
    Filed: April 13, 1992
    Date of Patent: July 20, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shoko Sakamoto, Haruo Akagi, Shoji Matsuda
  • Patent number: 5227796
    Abstract: A method of detecting the division of a radar target can detect a target, for instance caused by the release of a weapon from an aircraft which is tracked by a monopulse radar whose antenna is aligned onto the target with the aid of azimuth and/or elevation difference signals. Division of the radar target can be detected irrespective of whether the target is equipped with and uses an interference transmitter, by establishing a search channel in the radar difference channels. This channel has a sensitivity which is very low in a direction towards the tracked target, but which increases rapidly in directions which deviate somewhat from the direction towards the target. The search channel can be established by comparison of the absolute values of the signal levels in the difference channels with a threshold value.
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: July 13, 1993
    Assignee: Telefonaktiebolaget L M Ericsson
    Inventor: Erik R. Arvidsson
  • Patent number: 5227799
    Abstract: A road void search radar system includes a rotary encoder, a radar controller, an analyzer, and a recording unit. The rotary encoder generates a pulse signal having a period corresponding to a predetermined distance interval traveled by a vehicle. The radar controller outputs a wave every time the pulse signal is supplied from the rotary encoder. The analyzer analyzes an underground state by processing the output signal received from the radar controller. The recording unit records digital data signals and analyzes results.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: July 13, 1993
    Assignee: Mitsui Engineering & Shipbuilding Co., Ltd.
    Inventors: Noriaki Kimura, Kanji Murasawa, Masuo Konishi
  • Patent number: 5225838
    Abstract: An AWTSS is shown to be made up of an improved synthetic aperture radar (SAR) for generating radar maps with various degrees of resolution required for navigation of an aircraft and detection of ground targets in the presence of electronic countermeasures and clutter. The SAR consists, in effect, of four frequency-agile radars sharing quadrants of a single array antenna mounted within a radome on a "four axis" gimbal with a sidelobe cancelling subarray mounted at the phase center of each quadrant. Motion sensors are also mounted on the single array antenna to provide signals for compensating for vibration and stored compensating signals are used to compensate for radome-induced errors. In addition, a signal processor is shown which is selectively operable to generate radar maps of any one of a number of desired degrees of resolution, such processor being adapted to operate in the presence of clutter or jamming signals.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: July 6, 1993
    Assignee: Raytheon Company
    Inventors: Irving Kanter, Donald C. Null, George W. Ogar, Theodore J. Peregrim
  • Patent number: 5225839
    Abstract: An AWTSS is shown to be made up of an improved synthetic aperture radar (SAR) for generating radar maps with various degrees of resolution required for navigation of an aircraft and detection of ground targets in the presence of electronic counter-measures and clutter. The SAR consists, in effect, of four frequency-agile radars sharing quadrants of a single array antenna mounted within a radome of a "four axis" gimbal with a sidelobe cancelling subarray mounted at the phase center of each quadrant. Motion sensors are also mounted on the single array antenna to provide signals for compensating for vibration and stored compensating signals are used to compensate for radome-induced errors. In addition, a signal processor is shown which is selectively operable to generate radar maps of any one of a number of desired degrees of resolution, such processor being adapted to operate in the presence of clutter or jamming signals.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: July 6, 1993
    Inventors: Frank A. Okurowski, Rosario Mangiapane, Theodore J. Peregrim, Arthur Crain
  • Patent number: 5223840
    Abstract: A moving target simulator is provided for testing a wide variety of radars ithout the need for a direct connection between the simulator and the radar under test. The simulator accurately replicates the pulse width and amplitude of transmitted radar signals and provides a delay feature that permits simulated target scenarios to be presented to a radar under test. The simulator incorporates control features that allow Doppler frequency changes to be accounted for and that permit signal level changes to be made as in accordance with inverse 4th law distance-dependent target-return power variation.
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: June 29, 1993
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Willard M. Cronyn
  • Patent number: 5223839
    Abstract: An improved passive IFF system operating as a supplement to a conventional adar system including a coded variable delay system to produce like time-coded variable phase delayed identifying signal components indicative of cooperating or friendly objects and which overlap signals of other reflecting echo signals from the objects. The IFF system is provided with a retro-directive type antenna. The overlapping cooperating or friendly signal components and the corresponding other echo reflecting object signals are simultaneously detected at the radar system which is provided with a compensating or complementary phase delay means time coded in the same manner as the identifying IFF signal components. The identifying IFF signal components are thus produced in uniform phase and are summed up to provide a signal at the radar system whose magnitude is relatively large as compared to the combined corresponding echo reflecting signals which are in random-phase relationship.
    Type: Grant
    Filed: June 1, 1970
    Date of Patent: June 29, 1993
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Sidney J. Grossman
  • Patent number: 5223842
    Abstract: An AWTSS is shown to be made up of an improved synthetic aperture radar (SAR) for generating radar maps with various degrees of resolution required for navigation of an aircraft and detection of ground targets in the presence of electronic countermeasures and clutter. The SAR consists, in effect, of four frequency-agile radars sharing quadrants of a single array antenna mounted within a radome on a "four axis" gimbal with a sidelobe cancelling subarray mounted at the phase center of each quadrant. Motion sensors are also mounted on the single array antenna to provide signals for compensating for vibration and stored compensating signals are used to compensate for radomeinduced errors. In addition, a signal processor is shown which is selectively operable to generate radar maps of any one of a number of desired degrees of resolution, such processor being adapted to operate in the presence of clutter or jamming signals.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: June 29, 1993
    Assignee: Raytheon Company
    Inventors: Frank A. Okurowski, Rosario Mangiapane
  • Patent number: 5223837
    Abstract: A method and apparatus for preventing unauthorized sources from utilizing rcraft-borne I.F.F. for locating same. A bypass switch is inserted in the I.F.F. transponder antenna line which normally sends all incoming signals into a dummy load. Upon receipt of a proper interrogate command, the antenna is switched to the transponder.
    Type: Grant
    Filed: November 12, 1981
    Date of Patent: June 29, 1993
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Sidney J. Grossman
  • Patent number: 5223838
    Abstract: An apparatus and a method for enhancing the radar cross section of a target. The present invention is an impulse radar system that implements a method that comprises the following steps. A pilot impulse radar pulse is transmitted at a target. The pilot pulse comprises a plurality of individual pulses having respective distinct frequencies generated by the impulse radar system. A return pulse from the target is received by the impulse radar system and provides information indicative of target scattering centers. The return pulse is used as a calibration signal for generating a phase conjugated pulse. The phase conjugated pulse is then transmitted at the target. Processing a target return signal derived from the transmitted phase conjugated pulse enhances the radar cross section of the target because the waveform of the transmitted phase conjugated pulse is matched to the characteristics of the target.
    Type: Grant
    Filed: April 7, 1992
    Date of Patent: June 29, 1993
    Assignee: Hughes Aircraft Company
    Inventors: Raymond Tang, Kuan M. Lee, Ruey-shi Chu, Gordon L. Howard
  • Patent number: 5218358
    Abstract: A phase shifter assembly for use with a phased array antenna includes a plurality of phase shifter subarrays which are mounted on a ferri-magnetic substrate. There is a common power feed which is connected in series through a transmission line with each of the phase shifter subarrays. Additionally, a plurality of power combiners/splitters are connected into the transmission line to direct the proportionate power to each subarray. An alignment phase shifter is connected into the transmission line between adjacent subarrays and their associated power combiner/splitter. Separately from the transmission line, a driver is electronically connected in series with coils at each of the alignment phase shifters to alter the phase power which is fed into each of the subarray to align adjacent subarrays and produce a substantially continuous wave for the antenna.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: June 8, 1993
    Assignee: Hughes Aircraft Company
    Inventors: William A. Harrington, James V. Strahan
  • Patent number: 5214432
    Abstract: A radar absorbing material comprising multiple layers integrated to form a thin, flexible, and lightweight structure. The material includes a substrate having disposed thereon absorber elements that are resistively loaded to enable one to construct a device relatively small and thin size. The broadbanding of the device is carried out by multilayering concepts in which different size antenna patterns are multilayered with each layer designed to absorb frequencies in a specified range. The absorber elements are selected for their intrinsic impedance properties and preferrably be polarization insensitive. These absorber elements are disposed in a random and preferrably aperiodic pattern.
    Type: Grant
    Filed: February 16, 1990
    Date of Patent: May 25, 1993
    Assignee: Chomerics, Inc.
    Inventors: Raymond S. Kasevich, Michael Kocsik, Michael Heafey
  • Patent number: 5212488
    Abstract: The present invention provides reflecting chaff microellipsoids having a surface of electrically conducting material. A preferred embodiment consists of S.sub.i O.sub.2 (95%), Na.sub.2 O (1%), B.sub.2 O.sub.3 (4%) microspheres coated with silver. The present invention is best suited for reflecting electromagnetic radiation within the range of about 100 GHz to 100,000 GHz.
    Type: Grant
    Filed: January 21, 1992
    Date of Patent: May 18, 1993
    Inventor: John A. Konotchick
  • Patent number: 5208600
    Abstract: A surveillance sensor for detecting and monitoring aerodynamic conditions in a vicinity of an aircraft landing glide slope utilizes a radar transmitter to illuminate the glide slope. Radar reflections from aircraft induced vortices, clear air turbulence, and glide slope cross winds are received by a monopulse radar system wherein a sum beam doppler spectrum and a difference beam doppler spectrum for the radar returns is determined. The sum and difference beams doppler spectra are processed to determine the aerodynamic conditions in the glide slope vicinity. These aerodynamic conditions are assessed to determine whether aerodynamic hazardous conditions exist in the glide slope region.
    Type: Grant
    Filed: March 2, 1992
    Date of Patent: May 4, 1993
    Inventor: William L. Rubin