Patents by Inventor Juri G. Leetmaa

Juri G. Leetmaa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4908589
    Abstract: A dielectrically loaded waveguide switch is disclosed which provides high power handling capability, small size and low weight. The invention includes first and second dielectrically loaded waveguides selectively connected by a switch. In a specific embodiment of the invention, the switch includes a third dielectrically loaded waveguide mounted for communication with said first and second waveguides upon switch actuation.
    Type: Grant
    Filed: September 21, 1987
    Date of Patent: March 13, 1990
    Assignee: Hughes Aircraft Company
    Inventors: Richard V. Basil, Jr., Juri G. Leetmaa
  • Patent number: 4757292
    Abstract: A low noise coaxial microwave window of particular utility in hermetic and high power applications, having a metallic center conductor, a metallic outer support, and a ceramic support brazed between the two conductors. The brazed joints are specially prepared to have a series of layers and sublayers extending from the ceramic to the metal, as follows: ceramic, cermet, cermet-nickel alloy, copper-nickel alloy, copper, braze metal, and metallic piece. The nickel content of the cermet-nickel and copper-nickel alloys is limited so that the alloys are non-magnetic. The nickel-containing alloys assist in bonding the copper layer to the cermet in a reliable, reproducible fashion, but control of the nickel content avoids microwave intermodulation effects. Where the window separates a vacuum from another medium, the surface of the support contacting the vacuum is formed from at least two noncoplanar segments to eliminate the possibility of multipacting. The same techniques are used in waveguide microwave windows.
    Type: Grant
    Filed: August 8, 1986
    Date of Patent: July 12, 1988
    Assignee: Hughes Aircraft Company
    Inventors: Richard V. Basil, Jr., Meredith K. Eick, Juri G. Leetmaa, Donald G. Swartz
  • Patent number: 4736173
    Abstract: In a microwave resonator, a variable cavity-wall segmentation along the location of a propagational current null is employed for thermal-compensation purposes by utilizing it in conjunction with supplemental mechanisms which operate to counteract thermally-induced variations in the resonator's characteristic geometry. Because dimensional variations at a current null will have minimum impact on resonator coupling parameters, a variably-configured current-null segmentation serves in a minimal-impact fashion to absorb those thermally-induced dimensional variations which occur transverse to the null. Of the three specific mechanisms disclosed for variational counteraction in the typical context of a resonator having both longitudinal and transverse extent with respect to a propagational axis, the first is a thermally-invariant assembly which provides thermal stabilization by inhibiting variations in the resonator's characteristic longitudinal extent.
    Type: Grant
    Filed: November 3, 1986
    Date of Patent: April 5, 1988
    Assignee: Hughes Aircraft Company
    Inventors: Richard V. Basil, Jr., Juri G. Leetmaa
  • Patent number: 4156857
    Abstract: A method of eliminating a substantial portion of the nonlinear effects that occur in passive microwave devices operating under relatively high power conditions by use of small lightweight permanent magnets about the device structure while monitoring the level of such undesired signals.
    Type: Grant
    Filed: May 2, 1977
    Date of Patent: May 29, 1979
    Assignee: Hughes Aircraft Company
    Inventors: Neal C. Silence, Juri G. Leetmaa, Charles F. Montgomery
  • Patent number: 4028651
    Abstract: A coupled-cavity microwave filter including a plurality of relatively high Q cylindrical cavity filters, a relatively large non-adjustable iris aperture coupling adjacent ones of the cavities, a relatively smaller secondary tuning aperture located near the edge of the irises separating the cavities, each such secondary tuning aperture containing a tuning screw extending through the wall of the cavity in order to provide adjustment of the coupling between such adjacent cavities without degrading the cavity Q.
    Type: Grant
    Filed: May 6, 1976
    Date of Patent: June 7, 1977
    Assignee: Hughes Aircraft Company
    Inventor: Juri G. Leetmaa