Patents Represented by Attorney, Agent or Law Firm James A. DiGiorgio
  • Patent number: 5450227
    Abstract: A dual-gate self-oscillating mixer FET that is injection-locked from a remote LO frequency source. The dual-gate FET having a feedback circuit connected between the first gate port and the drain port that is tuned so that the FET can oscillate within a frequency range including a predetermined LO frequency. The FET having a remote synchronization circuit electrically connected to the FET first gate port to inject the predetermined LO frequency therein and lock the FET oscillation to that LO. Accordingly, the dual-gate FET mixes RF energy input to the second gate port with the locked LO injected in the first gate port and outputs the desired intermediate frequency through the drain port.
    Type: Grant
    Filed: May 3, 1993
    Date of Patent: September 12, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Thomas P. Higgins, Dana J. Sturzebecher, Roland Cadotte, Jr., Arthur Paolella
  • Patent number: 5448211
    Abstract: A planar, magnetically-tunable, band-rejection filter comprising a slot-l having at least one magnetically tunable, dielectric resonator-stack positioned on its top surface. The core of each resonator stack is filled with ferrite material. As a result, the filter provides a higher "Q", and thus provides greater suppression of unwanted microwave and millimeter-wave signals than the prior art.
    Type: Grant
    Filed: September 14, 1994
    Date of Patent: September 5, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Elio A. Mariani
  • Patent number: 5438308
    Abstract: A yokeless magnetic circuit composed of a permanent magnet shell having a lenoidal-cavity within which a working field is generated. The permanent magnet shell has a conical permanent end magnet adjacent each of its ends to insure that the surface at each of its ends is equipotential between the radial periphery of the permanent magnet shell and the axial centerpoint of the solenoidal cavity. The height of the conical end magnets directly depends of the magnetization and thickness of the permanent magnet shell and whether the internal field is uniform, gradient or variable.
    Type: Grant
    Filed: November 8, 1994
    Date of Patent: August 1, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Herbert A. Leupold, Ernest Potenziani, II
  • Patent number: 5428637
    Abstract: A method for reducing the synchronization overhead in Frequency Hopping communication systems. Generally, the method establishes a synchronization state during which a plurality of communications can take place without re-synchronization before each separate transmission. More particularly, the method establishes a synchronization period during which all the radios are initially synchronized, followed by a series of acknowledgment period and transmission periods during which any unit intending to transmit is assigned a specific time slot for such transmission.
    Type: Grant
    Filed: August 24, 1994
    Date of Patent: June 27, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: George R. Oliva, Jr., Gregory Lorenzo, Kenneth J. Loffer
  • Patent number: 5428335
    Abstract: A permanent magnet comprising a shell of magnetic material having a hollow avity and an access port that passes through the shell and communicates with the cavity. The shell is permanently magnetized to produce a magnetic field in the cavity. A magnetic insert is located in the cavity. The insert has a tunnel aligned with the access port and is magnetized in a direction opposite to the direction of the magnetic field. Specifically, a spherical magnetic shell has a concentric cavity in which a spherical magnetic insert is housed. An access port in the form of an axial hole passes through the spherical center of the shell and the insert. The shell ("magic sphere") is magnetized such that it is capable of producing a uniform magnetic field in the cavity. The insert is uniformly magnetized in a direction opposite to that of the cavity field produced by the shell. As such a working field that has a strength greater than that of the cavity field produced by the shell is located in the tunnel.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: June 27, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Herbert A. Leupold, Anup Tilak
  • Patent number: 5428334
    Abstract: A permanent magnet comprising a shell of magnetic material having a hollow avity and an access port that passes through the shell and communicates with the cavity. The shell is permanently magnetized to produce a magnetic field in the cavity. A magnetic insert is located in the cavity. The insert has a tunnel aligned with the access port and is magnetized in a direction opposite to the direction of the magnetic field. Specifically, a spherical magnetic shell has a concentric cavity in which a spherical magnetic insert is housed. An access port in the form of an axial hole passes through the spherical center of the shell and the insert. The shell ("magic sphere") is magnetized such that it is capable of producing a uniform magnetic field in the cavity. The insert is uniformly magnetized in a direction opposite to that of the cavity field produced by the shell. As such a working field that has a strength greater than that of the cavity field produced by the shell is located in the tunnel.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: June 27, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Herbert A. Leupold, Anup Tilak
  • Patent number: 5426402
    Abstract: A planar preselector filter with tunable narrowband excision composed of a errite substrate having a microstrip line with a fixed-tuned bandpass filter on one surface and a plurality of slotline resonators etched in a ground plane on an opposing surface. The fixed tuned bandpass filter is composed of short resonant elements of microstrip, having a length that is one-half the guide wavelength at the center frequency of its passband. The slotline resonators are positioned on the opposing surface of the substrate such that it suppresses or excises a predetermined narrowband of frequencies within the passband of the fixed-tuned bandpass filter. Moreover, the center frequency of the narrowband excision is varied by applying a tunable magnetic bias field of a predetermined strength across the ferrite substrate.
    Type: Grant
    Filed: August 19, 1994
    Date of Patent: June 20, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Elio A. Mariani
  • Patent number: 5396209
    Abstract: A light-weight permanent magnet structure having a permanent magnet shell that generates a high-intensity internal magnetic field that can be accessed without disrupting the uniformity of that internal field. Particularly, the permanent magnet shell is comprised of permanent magnet material that has a uniform magnetization at each polar angle around the shell, such that its size is minimized in regions where less than the maximum available magnetization of the material is required to maintain the internal field intensity. The resultant structure is a lightweight, low profile, low-cost distortion-free flux source that is easier to construct than the prior art.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: March 7, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 5382936
    Abstract: A permanent magnet comprising a shell of magnetic material having a hollow avity and an access port that passes through the shell and communicates with the cavity. The shell is permanently magnetized to produce a magnetic field in the cavity. A magnetic insert is located in the cavity. The insert has a tunnel aligned with the access port and is magnetized in a direction opposite to the direction of the magnetic field. Specifically, a spherical magnetic shell has a concentric cavity in which a spherical magnetic insert is housed. An access port in the form of an axial hole passes through the spherical center of the shell and the insert. The shell ("magic sphere") is magnetized such that it is capable of producing a uniform magnetic field in the cavity. The insert is uniformly magnetized in a direction opposite to that of the cavity field produced by the shell. As such a working field that has a strength greater than that of the cavity field produced by the shell is located in the tunnel.
    Type: Grant
    Filed: December 23, 1992
    Date of Patent: January 17, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Herbert A. Leupold, Anup Tilak
  • Patent number: 5382788
    Abstract: A monolithic photoconductive pulsar utilizing a radial transmission line structure to store energy and a unique optical pulse illumination means to trigger the radial transmission line to radiate extremely, high voltage gain, narrow bipolar pulses. By achieving a higher voltage gain, the bipolar RF pulses are desirable in that they substantially improve the efficiency and lifetime of the device over the prior art.
    Type: Grant
    Filed: July 16, 1993
    Date of Patent: January 17, 1995
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Anderson H. Kim, Robert J. Youmans, Maurice Weiner, Lawrence E. Kingsley
  • Patent number: 5355091
    Abstract: Disclosed is a real time interference signal rejection circuit which utils a conventional chirp-Z analyzer to generate a critical number and stop a counter circuit. The critical number is then read by a microprocessor which calculates new tap values from a set of predetermined tap values to reprogram a programmable filter.
    Type: Grant
    Filed: May 21, 1992
    Date of Patent: October 11, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Stuart D. Albert, William J. Skudera, Jr.
  • Patent number: 5351063
    Abstract: A photoconductive switch coupled to an energy storage device wherein the tch is comprised of photoconductive semiconductor material while the energy storage device comprises two spiral metalized arms that make up a spiral antenna. The photoconductive switch is electrically connected to the storage device to facilitate fast discharge of the stored energy through a load. A variation comprises a storage device comprising two separate pieces of substrate material each having a spiral metalized arm. The separate pieces being connected by highly dielectric material to form a spiral antenna ultra wideband radiator.
    Type: Grant
    Filed: May 19, 1993
    Date of Patent: September 27, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Anderson H. Kim, Leo D. DiDomenico, Maurice Weiner, Louis J. Jasper, Jr., Robert J. Youmans
  • Patent number: 5319218
    Abstract: A photoconductive ultra-wideband impulse generating device utilizing pulse harpening techniques to further increase its radiation frequency well above the gigahertz range while also substantially improving radiation efficiency. Such pulse sharpening provides for a radiator having a wider range of applications.
    Type: Grant
    Filed: May 6, 1993
    Date of Patent: June 7, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Anderson H. Kim, Maurice Weiner, Louis J. Jasper, Jr., Robert J. Youmans
  • Patent number: 5319340
    Abstract: A magnetic field source that produces a stepped field of greater magnitude than the remanence of the magnetic material used to construct it. The source is basically a magnetic igloo comprised of two hemispheres having different cavity flux value that are separated by a passive ferromagnet slab. The hemispheres are positioned such that they share the same radial center point. The slab has a predetermined thickness and a tunnel of predetermined radius passing through its center along the radial center point of said hemispheres such that the flux in the cavity of the hemisphere abruptly changes when passing from the first hemisphere flux to the second.
    Type: Grant
    Filed: July 28, 1993
    Date of Patent: June 7, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 5317321
    Abstract: A situation awareness display device for providing a graphical display of e relative position of remote units moving along with and in proximity to the local unit utilizing the device.
    Type: Grant
    Filed: June 25, 1993
    Date of Patent: May 31, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Paul F. Sass
  • Patent number: 5313209
    Abstract: A process for accurately predicting the effects of a sweep jammer signal, ose waveform is given, on a targeted radio receiver communication link whose signaling curve is known. The process analyzes the critical physical and electrical characteristics of both the sweep jamming signal and the targeted radio receiver, and determines whether the sweep jammer signal is perceived by the receiver as being a sweep jammer, a barrage jammer, or something in between the two. Moreover, the process determines the jamming signal's effect on the receiver's peak and background Bit Error Rates which are then used to accurately calculate the sweep jamming signal's effect on the average Bit Error Rate.
    Type: Grant
    Filed: November 12, 1993
    Date of Patent: May 17, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Paul A. Michaels, Jr., Ralph J. Romano, Francis Giordano
  • Patent number: 5313056
    Abstract: An electronically controlled frequency agile impulse source utilizing pulse sharpening techniques to increase its versatility in radiating impulse energy at a variety of center frequencies and bandwidths in the megahertz to the gigahertz range. Such pulse sharpening provides for a radiator having a wider range of applications.
    Type: Grant
    Filed: August 6, 1993
    Date of Patent: May 17, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Anderson H. Kim, Maurice Weiner, Louis J. Jasper, Jr., Robert J. Youmans, Lawrence E. Kingsley
  • Patent number: 5283584
    Abstract: A photoconductive switch coupled to an energy storage device wherein the tch is comprised of photoconductive semiconductor material while the energy storage device comprises two discrete dielectric mediums. Each medium having a conductive electrode on the top and bottom surfaces to essentially form parallel capacitors wherein the parallel capacitors are separated by a predetermined gap distance. A photoconductive switch electrically connected to each medium such that the switches are located on the opposite sides of their respective mediums. The predetermined gap distance (between the electrodes) and the photoconductive switches (on opposite sides of the storage devices) provide suppression of surface flashover between very high voltage, charged electrodes. Such flashover suppression allowing for very high power pulse generation.
    Type: Grant
    Filed: May 6, 1993
    Date of Patent: February 1, 1994
    Assignee: The United States of America as represented by the Secrtary of the Army
    Inventors: Anderson H. Kim, Maurice Weiner, Louis J. Jasper, Jr., Robert J. Youmans