Raytheon

About: Raytheon is a company organization based out in Waltham, Massachusetts, United States. It is known for research contribution in the topics: Signal & Antenna (radio). The organization has 15290 authors who have published 18973 publications receiving 300052 citations.

High frequency infrared emitter

Abstract: An infrared radiation emitter is provided that is capable of producing infrared radiation modulating at high frequency. The IR emitter includes a low-thermal-mass resistive membrane that is suspended by long thermal isolation arms over a substrate. The membrane is suspended over the substrate such that a resonant emitting cavity is formed between the membrane and the substrate. The low-mass, thermally isolated membrane design maximizes the temperature change induced by Joule heating of the resistive membrane and allows the emitted IR radiation to be modulated at high frequencies.

Digital communications system with immunity to frequency selective fading

Abstract: A digital communications system with increased resistance to frequency selective fading. Digital signals to be transmitted are phase shift modulated upon a spectrum spreaded carrier. The carrier is generated by mixing the output of a band spread oscillator with a locally generated IF oscillator signal. The signal thus obtained is divided into transmission periods, each of which is longer than the maximum spreading time of the nonlinear transmission medium. The increased bandwidth occupancy thus obtained increases the immunity of the transmitted signals to frequency selective fades moving across the allocated bandwidth. The signals are received by a differentially adaptive receiver which automatically adjusts its response to the envelope of received signals.

Optical magnetron for high efficiency production of optical radiation

Abstract: An optical magnetron is provided which includes a cylindrical cathode having a radius rc, and an annular-shaped anode having a radius ra and coaxially aligned with the cathode to define an anode-cathode space having a width wa=ra−rc. The optical magnetron further includes electrical contacts for applying a dc voltage between the anode and the cathode and establishing an electric field across the anode-cathode space, and at least one magnet arranged to provide a dc magnetic field within the anode-cathode space generally normal to the electric field. A plurality of resonant cavities are provided with each having an opening along a surface of the anode which defines the anode-cathode space. Electrons emitted from the cathode are influenced by the electric and magnetic fields to follow a path through the anode-cathode space and pass in close proximity to the openings of the resonant cavities to create a resonant field in the resonant cavities. The resonant cavities are each designed to resonate at a frequency having a wavelength λ, and circumference 2πra of the surface of the anode is greater than λ.

Confirmation of an Electron Avalanche Causing Laser-induced Bulk Damage at 1.06 microm.

Abstract: Measurements have been made on intrinsic optical bulk breakdown in ten alkali halides at 1.06 μm and in one at 0.69 μm. By comparing the results to previously reported experiments conducted at 10.6 μm and at direct current, it has been possible to identify the damage mechanism as electron avalanche breakdown. Self-focusing has been controlled by restricting the probe powers to well below the critical powers for catastrophic self-focusing, and damage from inclusions has been distinguished from intrinsic damage. Implications of this work for surface damage studies are explored.

Method for manufacturing a coaxial interconnect

Abstract: A multi-chip-module comprising a plurality of vertically layered substrates and including a plurality of coaxial inter-connects formed between and through the substrate layers. Each of the coaxial inter-connects is formed by a process wherein: an outer hole (aperture) is drilled through the substrate and lined with an electrically conductive material to form an outer via; the outer via is filled with a dielectric material; and, an inner hole (aperture) is drilled through the dielectric material and filled with an electrically conductive material to form a center via. The characteristic impedance of the coaxial inter-connect is determined by the selection of the outer diameters of the drilled holes for the outer and center vias.