University of Utah Research Foundation

USA As Represented by Secretary of the Navy

L-3 Communications Corporation

J Mark Baird

Larry R Barnett

R Jennifer Hwu

Laurence P Sadwick

Yue-Ying Lau

Richard W Grow

Michael B Kenny

Sherman Holmes

Darren J Corey

Roberto W Alm

The exemplary embodiments of the invention provide techniques that assist in the absorption, reduction or elimination of the resonance of unwanted cavity modes in a cavity measurement system, such as a cylindrical TEcavity measurement system used to measure various dielectric properties of a dielectric sample, for example. One non-limiting, exemplary system includes: sidewalls; a first endplate; a second endplate disposed opposite the first endplate so as to define a cavity bounded by the sidewalls, the first endplate and the second endplate; and first and second radio frequency (RF) coupling receptacles coupled to at least one of the sidewalls, the first endplate or the second endplate, wherein the first and second RF coupling receptacles are configured to pass a RF signal through the cavity. The first endplate has a plurality of conducting loops disposed on a surface facing the second endplate. Each loop of the plurality of conducting loops is electrically isolated from other loops of the plurality of conducting loops.

RF waveguide mode suppression in cavities used for measurement of dielectric properties

An integrated circuit vacuum tube array includes an insulating or highly resistive substrate, electrically conductive materials disposed on the substrate to define and surround a plurality of first voids extending from the substrate upwardly through the material, a plurality of cathodes disposed on the material to bridge over the respective first voids, for emitting electrons when heated by circuitry that selectively heats the cathodes, first electrically resistive material disposed on the electrically conductive material to surround the cathodes and define a plurality of second voids thereabove, an electrically conductive grid disposed on the electrically resistive material to project partially into the second voids to define an opening in the grid above each cathode, for allowing the passage of electrons therethrough, circuitry to selectively apply a voltage to the grid to control electron flow and thereby control the electrical current produced at the anodes, second electrically resistive material disposed on the grid to define a plurality of third voids above the openings in the grid, and a plurality of electrically conductive anodes disposed on the second electrically resistive material over the third voids to receive electrons emitted by the cathodes and thereby produce an electrical current.

Microminiature thermionic vacuum tube

A radio frequency millimeter-wave signal antenna and mixer system includes a dielectric substrate having a generally planar upper surface, and a ground-plane layer of conductive material disposed below the upper surface. This ground plane layer includes a plurality of spaced-apart low conductivity sections or windows to allow passage therethrough of radio frequency signals received at a surface of the substrate. A plurality of antennae are disposed on the upper surface of the substrate, with each antenna being positioned over a respective one of the windows in the ground-plane layer. A plurality of mixers are also disposed on the upper surface of the substrate, each adjacent a respective antenna for receiving radio frequency signals therefrom and for producing intermediate frequency signals. A plurality of output conductors are formed on the upper surface of the substrate, each being coupled to a respective mixer to extend therefrom alongside the antenna from which respective mixer receives radio frequency signals. The output conductors carry intermediate frequency signals from the respective mixers to the edge of the substrate.

Radio frequency antenna and mixer array

A gas ionization type vacuum gauge for testing the internal vacuum levels to below 10.sup.-6 torr is disclosed which uses a multipactor discharge means as the source for the electron current used to ionize residual gas molecules. The invention comprises an RF field enhancing cavity which can be constructed of high-vacuum-compatible materials, able to withstand bake-out microwave temperatures and a negatively biased ion collection wave, wire, or grid. A simple ceramic RF feed-through permits simple and noninvasive pressure measurements. The device can be made much smaller than conventional gauges.

Multipactor pressure gauge for use as a noninvasive vacuum tube sensor

A coupler employing two similar sections of waveguide which extend coliney in longitudinal succession. Adjacent ends of the guide sections are spaced apart to form a gap in the boundary of the sections. A third section of waveguide is disposed external to and coaxial with at least a part of each of the two waveguide sections to provide a boundary surrounding the gap. Electromagnetic energy propagating down one of the two similar sections of waveguide in a first mode and entering the gap is converted partly to a plurality of other modes. The converted energy is reconverted to the first mode upon reaching the other of the two similar sections of waveguide. The electric field pattern exciting the section of waveguide at the end of the gap and propagating down it is exclusively in the first mode. The cutoff-determining dimensions of the third section of waveguide and the gap separation are determined from the condition that the phase relationships between the modes at the end of the gap be the same, to within an integral multiple of 2.pi., as what they were at the beginning of the gap, to insure complete transfer of power between the two similar sections of waveguide.

Waveguide coupler using three or more wave modes

An RF cyclotron maser type traveling-wave amplifier including an integral active circulator. The amplifier includes a tapered interaction waveguide having a cross-section which gradually increases from a small first end to a larger second end thereof. The waveguide is capable of supporting first and second orthogonal polarization modes therein with approximately the same propagation characteristics for the two modes. A beam of mildly relativistic electrons having helical electron motion is directed into the small first end to axially propagate within the waveguide toward the larger second end. A tapered magnetic field is generated within the waveguide in a direction approximately parallel to the axis of the waveguide. The magnetic field is profiled to near grazing interaction with the second polarization mode of the waveguide. An input electromagnetic wave in the first polarization mode is launched into the larger second end of the waveguide to propagate toward the first end thereof. The input wave is reflected by the constriction of the tapered waveguide to co-propagate with the electron beam in the waveguide. The reflected input wave additionally excites energy in the second mode which also co-propagates with the electron beam. The first and second modes are amplified by the electron beam; the second polarization mode being amplified to a greater extent than the first mode. The two orthogonal modes are easily separated to provide input and output ports for the amplifier.

Growing community of inventors

Sandy, UT, United States of America

J Mark Baird