Patents Examined by Marvin L. Nussbaum
  • Patent number: 5012211
    Abstract: A microwave filter is composed of a set of circular cylindrical cavities arranged in cascade array and interconnected by irises having cross-slotted apertures for coupling electromagnetic power in two orthogonal TE.sub.113 modes. An input port is formed in a first of the cavities and an output port is formed in a last of the cavities. Each port is constructed as a transition between a section of rectangular waveguide and a section of circular waveguide, the section of circular waveguide being a portion of the first cavity and the last cavity, respectively, in the input and the output ports. The cross-sectional aspect ratio of the rectangular waveguide is 2:1. The ratio of a diameter of the cavity to length, as measured along a cylindrical axis in each cavity, is 0.26 thereby to provide for increased bandwidth while minimizing dispersion and transmission loss.
    Type: Grant
    Filed: September 2, 1987
    Date of Patent: April 30, 1991
    Assignee: Hughes Aircraft Company
    Inventors: Frederick A. Young, Roy K. Rikimaru
  • Patent number: 4897623
    Abstract: Arrays of printed circuit elements are placed in the E-plane inside waveges to reflect and pass selected bands of frequencies. The elements make no contact with the guide walls but are suspended on dielectric substrates and are held in place with foam dielectric.
    Type: Grant
    Filed: April 13, 1988
    Date of Patent: January 30, 1990
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: John Reindel
  • Patent number: 4896125
    Abstract: A dielectric notch resonator particularly suitable for use in a band reject filter operable at ultra-high frequencies comprises a dielectric resonator and an associated housing which results in a reactance having an imaginary component effectively nulled by a coupling reactance mechanism forming part of the dielectric notch resonator so as to present a relatively low resistive impedance load at a given center frequency and frequencies in a narrow bandwidth thereabout. The coupling reactive mechanism comprises an inductive wire and a serially connected variable capacitor so as to null the reactive component of the dielectric resonator at a particular center frequency and to modify the symmetry of the rejected frequency bandwidth by adjusting the capacitance of the variable capacitor.
    Type: Grant
    Filed: December 14, 1988
    Date of Patent: January 23, 1990
    Assignee: Alcatel N.A., Inc.
    Inventors: William D. Blair, Jr., Salvatore Bentivenga, Gregory J. Lamont
  • Patent number: 4896124
    Abstract: An integral phase shifting network of a transmitter filter provides a means to reduce the size and increase the efficiency of an antenna coupling network. The network to shift the phase of the transmitter filter is printed by depositing conductive material directly on a ceramic block using low-loss circuit elements and can be tuned easily by removing conductive material if required in certain applications. By utilizing an integral phase shifting network, either transmit or receive filters having a higly reactive and capacitive out-of-band impedance in the receive or transmit band, respectively, can be connected to a common antenna port without external transmission lines.
    Type: Grant
    Filed: October 31, 1988
    Date of Patent: January 23, 1990
    Assignee: Motorola, Inc.
    Inventor: Dale G. Schwent
  • Patent number: 4894628
    Abstract: A transmission delay line including a helical channel (2) formed in the surface of a cylinder (1), with a conductive sleeve (7) fitted to the cylinder to close the channel. A helical conductive member (4) is positioned within the channel (2) and spaced from the walls thereof by a dielectric material (5, 9).
    Type: Grant
    Filed: December 2, 1987
    Date of Patent: January 16, 1990
    Assignee: The Commonwealth of Australia
    Inventor: Peter J. Dadswell
  • Patent number: 4873587
    Abstract: A video signal reproducing apparatus for reproducing video signals from a record bearing medium on which many recording tracks are formed in parallel to each other with a given-period portion of the video signal recorded in each of the tracks are arranged: To compare, on the basis of signals reproduced by a reproducing head, the level of a reference signal with that of a reproduced state detection signal the level of which varies according to the reproduced state of the video signal; to determine, on the basis of the result of comparison, whether or not the video signal reproduced by the reproducing head is to be written into a memory device which is capable of storing the given-period portion of the video signal therein; and to change a level relation between the reproduced state detection signal and the reference signal from one level relation over to another according to the track pitch of the recording tracks which is detected using the signals reproduced by the reproducing head.
    Type: Grant
    Filed: August 25, 1987
    Date of Patent: October 10, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuji Yoshimura, Susumu Kozuki, Hiroo Edakubo, Chikara Sato
  • Patent number: 4873501
    Abstract: An improved transmission line filter element allows a higher difference between even and odd mode impedances than previously obtainable from planar structures. The filter element comprises a U-shaped gap formed in the strip conductor of a strip line transmission line, a microstrip structure or a suspended strip line structure. The internal transmission line filters can be cascaded to produce electromagnetic energy filters with deeper notches and steeper skirts than previously obtainable from other planar structures with the same number of elements.
    Type: Grant
    Filed: June 27, 1986
    Date of Patent: October 10, 1989
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Alfred R. Hislop
  • Patent number: 4866407
    Abstract: Four-terminal type noise filter having a first strip-like conductor with first inner and outer input/output leads each connected to the first conductor adjacent each end, a second strip-like conductor with second inner and outer input/output leads each connected to the second conductor adjacent each end, and dielectric sheets superimposed on the respective strip-like conductors. The sandwich of conductors and dielectric sheets are rolled into a flat tube such that the first and second inner leads defines a set of input and output terminals and said first and second outer leads defines another set of input and output terminals. The filter positively minimizes noise received by the filter without creation of ringing.
    Type: Grant
    Filed: July 13, 1988
    Date of Patent: September 12, 1989
    Inventor: Takeshi Ikeda
  • Patent number: 4864259
    Abstract: A ladder-type electric filter circuit apparatus having a plurality of thinner electric filter units wherein each electric filter unit includes a casing of metal into which piezoelectric resonator elements and terminal plates are inserted, and the metal casing is securely mounted on a printed circuit board by soldering. The piezoelectric resonator elements and terminal plates are insulated from the metal casing by an insulating plate and an elastic insulatiang plate which is also served as a vibration or shock absorber for protecting the contained filter from any external vibration or shock propagated through the printed circuit board.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: September 5, 1989
    Assignees: NGK Spark Plug Co., Ltd., NEC Corporation
    Inventors: Kenji Takamoro, Kenji Mizoe, Tatsuo Ogawa, Yasuhiko Nakagawa
  • Patent number: 4859972
    Abstract: A continuous microstrip phase shifter suitable for use in a phased array microwave hyperthermia system operating at 915 MHz is provided. The phase shifter utilizes a three dB quadrature hybrid coupler in conjunction with microstrip lines to change the phase of a transmitted wave. The phase change is introduced through the reflection ports of the coupler which are loaded with identical parallel resonant circuits. An abrupt junction varactor capacitance in parallel with a distributed inductance forms a voltage-tunable resonant circuit. The resonant element values are chosen to give a specified continuous phase variation with minimum transmission loss. This is accomplished without additional microwave circuit elements.
    Type: Grant
    Filed: November 1, 1988
    Date of Patent: August 22, 1989
    Assignee: The Board of Trustees of the University of Illinois
    Inventors: Steven J. Franke, Ronald D. Boesch, Richard L. Magin
  • Patent number: 4857871
    Abstract: A tunable ferrimagnetic resonator containing microwave filter with a plural piece housing is described. First and second body laminations are provided with channels and openings which form passageways and resonator receiving cavities when the laminations are assembled. These passageways and openings are preferably formed by chemical milling. Closure elements or shims overlay and close the ends of the resonator cavities. The body laminations and closure elements are of a nonmagnetic metal and are typically formed from flat thin sheets of material. Cover laminations, such as of plastic, clamp the closure and body laminations together and provide strength to the overall housing structure. Microwave filters of this invention are capable of being tuned up to 40 Gigahertz and higher.
    Type: Grant
    Filed: October 31, 1988
    Date of Patent: August 15, 1989
    Inventor: David L. Harris
  • Patent number: 4853658
    Abstract: The invention provides a phase-shifting device for inclusion into a microwave transmission line to effect a predetermined, constant, broadband shift in phase of transmitted signals. The device comprises, in its preferred form, two Gallium Arsenide field effect transistors, connected in parallel, serially included in the line, and means for switching the transistors between alternate states to effect the phase shift.
    Type: Grant
    Filed: June 27, 1988
    Date of Patent: August 1, 1989
    Assignee: Plessey Overseas Limited
    Inventor: Anthony A. Lane
  • Patent number: 4853660
    Abstract: Integratable microwave devices such as a tuneable band reject filter or an r.f. switch are provided on a gallium arsenide substrate having a (100) orientation. Each of the devices includes a layer of a ferromagnetic material having a pair of easy axes which lie in the plane of said (100) orientated substrate and a layer of a conductive, nonmagnetic material disposed thereover. The ferromagnetic material has a ferromagnetic resonant frequency related to the applied DC magnetic field, the anisotropy field, the saturation magnetization, and gyromagnetic ratio. Such devices are provided by utilizing the ferromagnetic resonant properties of the ferromagnetic material disposed on the (100) substrate.
    Type: Grant
    Filed: June 30, 1988
    Date of Patent: August 1, 1989
    Assignee: Raytheon Company
    Inventor: Ernst F. R. A. Schloemann
  • Patent number: 4851797
    Abstract: In a 1/2 wavelength side coupling filter, a plurality of resonance lines (4) are arranged on a board (20) in parallel to each other in a staggered manner so that respective ends thereof have step portions. An input coupling line (3) is arranged in parallel to the plurality of resonance lines, with an input end (5) formed opposed to an intermediate position of the adjacent resonance line and one end portion (6) formed aligned with one end portion of the adjacent resonance line. An adjusting line (7) is formed extending from one end portion (6) on the input coupling line, and the filtering characteristics adjusted by the adjusting line.
    Type: Grant
    Filed: July 28, 1988
    Date of Patent: July 25, 1989
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Makio Nakamura
  • Patent number: 4849723
    Abstract: A waveguide filter (100) is provided for functioning as a cable feed-through for previously terminated cables (50). Waveguide filter feed-through (100) includes a housing (110) of predetermined length having a plurality of bores (130, 140) extending therethrough. One of the bores (140) being centrally located, with each of the other bores (130) being located radially about the central bore (140). Each of the radially located bores (130) form an individual waveguide when a plug (120) is inserted within the central bore (140). Each of the waveguide passages (130) include a longitudinal passage extending the full length of housing (110) and opening into the central bore (140).
    Type: Grant
    Filed: May 25, 1988
    Date of Patent: July 18, 1989
    Inventor: Harry S. Oliver, Jr.
  • Patent number: 4849724
    Abstract: A waveguide band-pass filter has at least two resonators each consisting of a high-impedance section and a low-impedance section. The resonators are cascade-connected at intervals of .lambda.g/4 in a waveguide.
    Type: Grant
    Filed: December 8, 1988
    Date of Patent: July 18, 1989
    Assignee: NEC Corporation
    Inventor: Shuichi Koreeda
  • Patent number: 4845447
    Abstract: A trap filter assembly of the type employed with a video cable system to block a particular band of video frequencies has a housing formed as a generally rectangular block of square cross-section, made of cast aluminum or other suitable material. A cavity formed in the housing has first and second compartments which are separated from one another by a pair of barrier walls that define therebetween a channel passageway that extends from one corner of the first cavity compartment to a laterally opposite corner of the second cavity compartment. This prevents any direct line of sight signal path for stray video signals between the first and second compartments. First and second printed circuit filter boards are mounted in the compartments, preferably by a threaded fastener which mounts the boards onto respective pedestals in the compartments. A bare-braid coax conductor passes through the channel between the barrier walls and unites the signal paths on the two boards in the respective compartments.
    Type: Grant
    Filed: November 18, 1988
    Date of Patent: July 4, 1989
    Assignee: Northeast Filter Co., Inc.
    Inventor: Timothy M. Holdsworth
  • Patent number: 4843558
    Abstract: A regulation for a gas engine with a rotational speed probe for the crankshaft rotational speed, with a rotational speed-load-ignition angle-performance graph memory read out during each crankshaft rotation, with an ignition pulse generator controlled by the performance graph memory, with a lambda-probe, with a load probe, with a vacuum-controlled gas pressure adjusting device for the propulsion gas and with a flow-mixing device for the propulsion gas and the air. The invention provides a regulation for a gas engine which offers a full utilization of the possibilities of the gas engine above all in lean operation and in the partial load range. A rotational speed-load-lambda-performance graph (36) is provided for producing lambda-desired values. The lambda-desired values readied by the rotational speed-load-lambda-performance graph (36) are compared with the lambda-actual values under formation of a lambda difference value.
    Type: Grant
    Filed: June 29, 1987
    Date of Patent: June 27, 1989
    Assignees: Daimler-Benz Aktiengesellschaft, Atlas Fahrzeugtechnik GmbH
    Inventors: Horst Bergmann, Helmut Daudel, Burkhard Brandner, Klemens Klueppel
  • Patent number: 4843355
    Abstract: A programmable mechanical delay line is disclosed comprising one or more lengths of axially movable co-axial cable. The inner and outer conductors of the cable length are respectively accepted within cavities having electrically conductive inner walls. The conductors are electrically coupled to the cavity walls by respective toroidal springs which circumvent the conductors and which contact the cavity walls at their outer diameter. The minimal surface contact by the toroidal springs reduces wear and friction. The reduction in friction substantially eliminates overshoot which previously resulted from attempts to rapidly reposition the coaxial cables. Consequently, the disclosed device provided very rapid, repeatable, and accurate adjustment as different amounts of signal delay are desired.
    Type: Grant
    Filed: June 14, 1988
    Date of Patent: June 27, 1989
    Assignee: Colby Instruments, Inc.
    Inventor: Siegfried G. Knorr
  • Patent number: 4841265
    Abstract: A surface acoustic wave (SAW) filter has a piezoelectric substrate and a conductive transducer formed over the substrate. The transducer has first and second bus bars arranged in parallel at a prescribed interval from each other, a plurality of pairs of first electrode fingers having the same lengths, and a plurality of pairs of second electrode fingers having the same lengths. The tips of the second electrode fingers are positioned opposite those of the first electrode fingers. The transducer also has first and second weighted electrode pairs positioned between two adjacent pairs of the first electrode fingers and two adjacent pairs of the second electrode fingers, respectively.
    Type: Grant
    Filed: September 26, 1988
    Date of Patent: June 20, 1989
    Assignee: NEC Corporation
    Inventors: Takaya Watanabe, Shigeo Fushimi