US Government as Represented by the Secretary of the Army

Other

USA as Represented by Secretary of the Navy

University System of Maryland

The United States of America

Louis J Jasper, Jr

Maurice Weiner

Anderson H Kim

Robert J Youmans

Thomas E Koscica

Charles M DeSantis

Robert J Zeto

Leo D Didomenico

Stephen E Saddow

James F Baxendale

Douglas A Kirkpatrick

George K Lucey, Jr

Lawrence J Bovino

Lawrence E Kingsley

Roger D Kaul

Charles M De Santis

George Merkel

Chi Hsiang Lee

Arthur H Gottfried

John J Tancredi

George Bergeron

Alba Lalitha Ramaswamy

Joseph R Miletta

Eric Funk

Chance Glenn

K Ming Leung

Lawrence Carin

Thomas J Gher

Louis E Jasper

A printed circuit Traveling-Wave Tube (TWT) with a vacuum housing containing either a pair of identical meanderline slow-wave interaction circuits or a pair of multi-arm spiral slow-wave interaction circuits printed on two identical Photonic Band Gap crystal structures, and a gridded electron gun assembly. Printed on the two identical Photonic Band Gap crystal structures are electrical connections to connect the heater, cathode, grid and acceleration electrodes of the electron gun assembly to a power supply, RF input and output connectors surrounded by ground planes, a depressed collector, and a set of electrical connections to the depressed collector. Zig-zag metal spacers between the two identical Photonic Band Gap crystal structures are used to form the electron beam vacuum gap. Printed conducting metal strips on each side of the meanderline slow-wave interaction circuits are used for electrostatic focusing and to reduce beam edge effects of a sheet electron beam.

Traveling-wave tube with a slow-wave circuit on a photonic band gap crystal structures

A laser activated grenade is provided which includes a controllable laser source activated at specific times to generate radiation pulses. An energetic material within the grenade is ignited upon delivery of the generated radiation pulses. A propellant charge material triggers a propellant explosive train when the energetic material ignites. The grenade further includes load materials which are selectively activated once the propellant explosive train has been launched. The laser source may be located remotely from the grenade in order that the generated radiation pulses travel to the grenade through a fiber optic cable. Alternatively, the laser source may be embedded in the grenade and activated by a microwave/RF coded signal received from a remote signal transmitter. The grenade may carry a number of load materials so that each load material is activated either alone to produce a desired target effect, or in combination to produce a cumulative target effect such as light, sound, malodorous, as well as other incapacitating phenomena. In lethal implementation, the grenade may include shrapnel as a load which explodes when detonated at the target.

Laser-activated grenade with agile target effects

A device for generating and radiating pulses of radio frequency/microwave energy in response to pulses of laser light in which a metal layer is ohmically bonded to each side of a substrate of semiconductior material and an antenna bowtie pattern is ohmically bonded to the metal layers to form a feed structure for a Luneburg lens type antenna. There is at least one aperture available on the substrate of the semiconductor material for permitting laser light to reach the disk to produce photoconduction. The photoconductive switch is electrically connected to the storage device to facilitate fast discharge of the stored energy through the switch. The feed structure is mounted on a motorized support stand, which is connected to a center post by an arm that can rotate 360&deg; in the azimuthal direction and &plusmn;90&deg; in elevation. The feed structure is located on the outermost shell of the Luneburg lens, and is concave to conform to the focal radius of curvature of the outermost shell. The feed structure remains at a fixed radius from the center of the Luneburg lens as it rotates about the outermost shell. One embodiment uses a hemispherical Luneburg type lens to produce a highly directional beam by having the rays from the feed structure enter the Luneburg lens and reflect off of the ground plane. The other embodiment uses a spherical, or an almost spherical Luneburg type lens to produce a highly directional beam by having the radiation from the feed structure enter the Luneburg lens and speadout to emerge from the opposite diagonal point as a parallel beam. Both embodiments can rapidly scan 360&deg; in the azimuthal direction and approximately &plusmn;90&deg; in elevation.

Microwave generator/radiator using photoconductive switching and dielectric lens

An apparatus using field emission techniques to limit voltage on RF transmission lines. A voltage limiter comprises a cathode and an anode housed in an airtight tube, whereby the cathode comprises a field emitter array having a plurality of field tips distributed about the surface of an insulating layer, and a microstrip transmission line overlying the insulating layer and having a predetermined width to form electrical contact with a selected group of the field tips. The microstrip transmission line enables propagation of electromagnetic microwave energy over a bandwidth of multiple octaves. The field emitters enable the generation of a flow of electrons at a predetermined breakdown threshold voltage, without the necessity for an external source to induce electron flow. Generation of the electron flow by the field tips creates a reflection wave on the transmission line that interferes with the incident electromagnetic energy to limit the voltage on the transmission line.

Microwave field emitter array limiter

A projectile with an Air Pressure Wave Generator, a battery, fuze, safe and arm system, detonator system, and ancillary circuitry. The Air Pressure Wave Generator contains a supersonic or subsonic nozzle, an ogive, and a secondary propellant chamber, which contains a conventional high explosive and is consistent with the &ldquo;form-fit&rdquo; of the weapon rifling system, and designed so as to produce the desired Air Pressure Wave impulse on the target. The projectile also has chemical agent(s) and marker(s) inside the secondary propellant chamber, and/or inside the Air Pressure Wave Generator section that is located intermediate between the nozzle and projectile housing. The types and amounts of chemical agent(s) and marker(s) are consistent with the Air Pressure Wave Generator design to entrap the chemical agent(s) and marker(s) in the core or central section of the APW packet. The properties and parameters of the chemical agent(s) and marker(s) are chosen to produce the desired target effects and minimize unwanted spillage.

Projectile with an air pressure wave generator and chemical agent/marker

A high-gain, dielectric loaded, slotted waveguide antenna having a photonic bandgap, a high-impedance electromagnetic structure, in contact with the waveguide surface containing longitudinal slots, and a tailored dielectric material structure in contact with the outer surface of the photonic bandgap structure. The tailored dielectric structure at the inner most surface has the same effective dielectric constant of the waveguide material and the photonic bandgap structure. The effective dielectric constant is then incrementally or continuously reduced to have a dielectric constant close to that of the free-space value at the outer surface further distance from the waveguide array. The tailoring of the effective dielectric constant is achieved by layering a given number of slabs of different dielectric constants with sequentially reduced values, or by varying the chemical composition of the material, or by varying the density of the material imbedded with high dielectric constant particles.

High-gain, dielectric loaded, slotted waveguide antenna

The present invention provides multidimensional stacked photonic band gap crystal structures improving the performance of current planar monolithic antennas and RF filters by forbidding radiation from coupling into the substrate thereby significantly enhancing radiation efficiency and bandwidth. This invention comprises a number of sub-crystals with each having at least two lattices disposed within a host material, each lattice having a plurality of dielectric pieces arranged and spaced from each other in a predetermined manner, the sub-crystals being stacked in a crystal structure to provide a photonic band gap forbidding electromagnetic radiation propagating over a specially designed frequency band gap, or stopband. Both two dimensional and multidimensional crystals are disclosed. The preferred embodiment is a three-dimensional photonic band gap crystal comprising two or more sub-crystals, with each sub-crystal having a diamond-patterned lattice constructed from a plurality of dielectric zigzag pieces orthogonally interconnected, disposed within a host material.

Ultra-wideband photonic band gap crystal having selectable and

A photoconductive spread-spectrum communications system that includes a tsmitter and a receiver. The transmitter includes an oscillating laser, a Pockels' cell, a delay cell, a photoconductive switch, and an antenna for transmitting an electromagnetic spread-spectrum signal. The receiver includes an oscillating laser, a Pockels' cell, an antenna for receiving a spread-spectrum signal, a photoconductive switch, a filter, and a threshold detector for regenerating the signal contained within the spread-spectrum transmission.

Photoconductive spread-spectrum communications system

A photon triggered RF radiator having separate sections to perform the eny storage and the energy radiation functions. The energy storage function is performed by at least one charging electrode positioned on the upper surface of a photoconductive dielectric substrate, whereas the energy radiation function is performed by a charging electrode positioned adjacent to the charging electrode on the upper surface of the substrate. The charging electrode and the radiating electrode are separated by a predetermined gap distance that is large enough to insure there is no surface flashover between the electrodes and small enough to insure the efficiency of energy discharge from the charging pad to the spiral antenna is maximized.

Photon-triggered RF radiator having discrete energy storage and energy

A device for radiating pulses of radio frequency energy in response to pulses of laser light in which a metal layer is ohmically bonded to one side of a substrate of semiconductor material and an antenna is ohmically bonded to the other side of the substrate, there being at least one aperture in the metal layer for permitting laser light to reach the disk.

Optically activated multi-frequency high power RF generation utilizing a

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.

Ultra-wideband high power photon triggered frequency independent

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.

Pulse sharpening using an optical pulse

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.

Electronically controlled frequency agile impulse device

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.

High power photon triggered ultra-wideband RF radiator with opposite

The combination of a photoconductive switch coupled to an energy storage ice wherein the switch is comprised of photoconductive semiconductor switch while the energy storage device comprises a tapered radio transmission line. A photoconductive semiconductor gallium arsenide switch is embedded in a circular disc of dielectric material having a thickness dimension which reduces linearly outward from the center, with upper and lower layers of continuous radial metallization configured in a circular pattern located thereon. The upper layer of metallization includes an apertured grid adjacent one surface of the switch, while the outer conductor of a coaxial output signal line is connected to the metallization layer on the opposite side with the inner conductor thereof passing through the dielectric layer to the undersurface of the semiconductor switch.

Growing community of inventors

Fulton, MD, United States of America

Louis J Jasper, Jr