Northrop Corporation

University of California

Northrop Grumman Systems Corporation

William Hant

Mau-Chung Frank Chang

Daquan Huang

John W Tully

Benedict B O'Brien

King L Hu

Silvan Stanley Locus

Kenneth M Mitzner

John C Bryant

Darin S Hunzeker

Tuning devices and methods are disclosed. One of the devices comprises a metal structure connected with artificial dielectric elements, and variable capacitance devices. Each variable capacitance device is connected with a respective artificial dielectric element and with a control signal. Control of the variation of the capacitance allows the desired tuning. Another device comprises metallic structures connected with artificial dielectric elements and switches connected between the artificial dielectric elements. Turning ON and OFF the switches allows the capacitance between artificial dielectric elements to be varied and a signal guided by the metallic structures to be tuned.

Tunable artificial dielectrics

A probe for measurement of an electrically conductive surface covered by an insulating cover layer has a pair of electrically conductive pads for capacitive coupling to the conductive surface. The pads may be formed by photolithography as part of a disk of a metallic layer disposed on a substrate of low dielectric material such as fibrous glass in an epoxy binder, the pads being separated by a relatively narrow gap. Included within the probe is an electrically insulating holder for supporting the substrate and the pads, the holder being configured to facilitate manual manipulation of the probe. The probe connects with a signal analyzer which provides a test signal coupled to the pads via a coaxial transmission line. During a sliding of the pads along the cover layer, electrical characteristics of a signal coupled capacitively via the pads to the conductive surface are analyzed by the analyzer to provide information on electrical continuity and resistivity of the surface.

Capacitive disk probe

A fixture for determining RF characteristics of a dielectric medium comprises a first coupler having an RF through-window with input and output ports, the input port connectable to a waveguide input. A second coupler has an RF through-window with input and output ports, the output port connectable to an output waveguide. A plurality of rods are aligned with the axes of the input and output waveguides and connect the output port of the first coupler to the input port of the second coupler. Each rod is passable through the dielectric media and mates with the input port so as to form a continuous waveguide passing through the dielectric media.

Demountable wire cage waveguide for permittivity measurements of

A bipolar transistor is constructed to include a substrate, a collector layer epitaxial grown on the substrate and a base layer ion implanted in the collector layer. Next a further epitaxial layer is grown on the collector layer over the ion implanted base layer. A base contact region is ion implanted in this further epitaxial layer between the surface of this further layer and the base layer. The base contact region surrounds and defines an emitter in the further layer. A base ohmic contact is formed on the surface of the further layer in a location overlaying and contacting the base contact region. An emitter ohmic contact is also formed on the surface of the further layer in contact with the emitter. Additionally a collector ohmic contact is also formed on this same surface in a position isolated from the emitter by the base contact region. The collector ohmic makes an electrical contact with the collector by utilizing the further layer as a contact pathway.

Planar bipolar transistors including heterojunction transistors

Planar bipolar transistors including heterojunction transistors and

Thermionic filaments are arranged in an array which covers a predetermined area. A spreader electrode which may be in the form of a flat plate is placed on one side of the filaments with an anode being placed on the other side of the filaments, and an accelerator grid, focusing plate and collimation plate being placed in that order between the filaments and the anode. The anode is in the form of a foil through which the electrons pass into an area where they are utilized, such as for example a laser cavity where they are utilized to ionize the laser gas. The foil anode is supported on an apertured structure which facilitates the formation of a vacuum tight seal of the vacuum envelope containing the gun and functions as a heat sink to dissipate some of the heat energy developed in the foil. The anode support structure, focusing plate and collimating plate all have apertures formed therethrough which form a plurality of cylindrical channels, these channels covering substantially the entire surface area of the foil anode. The apertures of the support structure, focusing plate and collimation plate are aligned with each other to provide channeled pathways for the electrons between the filaments and the anode. Potentials are applied to the focusing and collimation plates to focus the electrons into circular beams which efficiently pass through the channels between the filaments and the anode with a minimum dissipation of energy in the structures forming the channels.

Area electron gun employing focused circular beams

A plurality of thermionic filaments are arranged in side-by-side relationship. A spreader electrode which may be in the form of a flat plate is placed on one side of the filaments, while an anode is placed on the other side of the filaments, with a grid being interposed between the filaments and the anode. The various aforementioned elements are given dimensions and positioned relative to each other and the voltages thereon adjusted so as to shape the trajectory of the electrons to provide a uniform distribution of electrons at the anode with a minimum dissipation of energy in the grid and spreader electrodes.

Growing community of inventors

Los Angeles, CA, United States of America

William Hant