Showing papers by "Raytheon published in 1978"

Integrated circuit device package interconnect means

Abstract: An integrated circuit device package is disclosed wherein a pair of dielectric support structures are provided, each one having a pattern of electrical conductors for interconnecting integrated circuit devices disposed thereon. The electrical conductors have end portions terminating into a plurality of contact pads disposed on a first surface of the support structures. A first one of the pair of support structures has corresponding contact pads on a second, opposite surface of the support structure, each one of the contact pads on the first surface being electrically connected to a corresponding one of the contact pads on the second surface. A dielectric spacer having a plurality of electrical contact pins is disposed between the pair of support structures. One end of each pin is electrically connected to a corresponding one of the contact pads disposed on the second surface of the first one of such structures, and the other end of such contact pin is electrically connected to a corresponding one of the contact pins disposed on the first surface of the second one of the structures. The contact pins are relatively short and thereby provide a relatively short electrical interconnect for the integrated circuit devices, thereby reducing parasitic capacitances normally associated with electrical interconnects.

In situ radio frequency selective heating process and system

Abstract: The process and apparatus for extracting the products of kerogen in situ from an oil shale body by supplying energy selectively to the kerogen by high frequency electric fields in the frequency range between 100 kilohertz and 1000 megahertz at an intensity which heats the kerogen to a temperature range between 250° C. and 500° C. to allow pyrolysis of the kerogen prior to substantial heat transfer to the surrounding mineral portions of the oil shale.

Method of operating a continuous wave radar

Abstract: A method of operating a continuous wave radar to derive range information as well as Doppler information is described. The transmitted signal is frequency modulated at a low modulation frequency and peak deviation so that range ambiguities are effectively avoided and echo signals may be processed at a relatively low intermediate frequency, thereby allowing echo signals from clutter to be more effectively rejected and echo signals from a moving target to be correlated.

Maximum entropy spectral estimation using the analytical signal

Abstract: Using maximum entropy power spectral estimation, the estimate of the frequency of a sinusoid in white noise has been shown to be very sensitive to the initial sinusoidal phase. This phase dependence can be significantly reduced by replacing the real data by its analytic form, reducing the sampling rate by two, and employing the power spectral estimate for complex data.

First-order statistics of a non-Rayleigh fading signal and its detection

Abstract: The first-order statistics of the vecter sum of a complex Gaussian variable and N complex exponentials with constant amplitudes but random independent phases are used to model a non-Rayleigh fading signal. Envelope detection, optimal for detecting Rayleigh (N = 0) and Rician (N = 1) signals, is also shown to be optimal for the considered non-Rayleigh signals in additive white Gaussian noise. However, the signal-to-noise ratio required to detect the latter signal for N = 2 may be substantially higher than for the former cases. Possible applications of this fading model to studies of multipath fading, non-Rayleigh sea echoes, microwave or laser radar detection and tracking are discussed.

Design of efficient coding and modulation for a Rayleigh fading channel

Abstract: The design of a coding/modulation structure for digital communications over a Rayleigh fading channel, the structure of the corresponding decoder, and the error rate performance of the resulting system are considered. Emphasis is on the use of constant weight codes for constructing equal energy waveforms for transmission over the channel. The performance gains that are achieved by the integrated coding/modulation approach relative to conventional methods for obtaining diversity are illustrated via some examples. Of special interest is the use of a concatenated coding technique for forming codes of large distance and hence high diversity. A new decoding algorithm is applied to enable efficient decoding of the concatenated code. An example is included that shows a performance increase of several dB resulting from concatenation.

Semiconductor integrated circuit structures and manufacturing methods

Abstract: A semiconductor integrated circuit structure wherein a first metal interconnecting system is formed on a semiconductor body having active and/or passive elements formed therein. An insulating layer is deposited on the first metal interconnecting system. Apertures are formed in selected regions of such layer and are cleaned in a sealed sputtering chamber. A refractory metal is deposited over the insulating layer and through the apertures onto the first metal interconnecting system in a sealed sputtering chamber. A lead metal is deposited over the refractory metal layer. Selected portions of such refractory metal and lead metal are removed to form a second metal interconnecting system. With such structure and method the surfaces of the first metal interconnecting system which are to be connected to a second metal interconnecting system through the apertures are cleaned of oxides and other contaminates in a sealed sputtering chamber and are then sealed from further contamination by the refractory metal layer. The method improves the electromigration resistance of the second metal interconnecting system because of the presence of the refractory metal layer. Further, the refractory metal layer acts as a barrier layer which reduces interdiffusion between the connected portions of the first and second interconnecting systems. The assurance of good ohmic contact between the connected portions of the interconnecting systems reduces the surface area required for metallization.

Corn popper with butter dispenser

Abstract: A microwave corn popper having means for dispensing butter during or shortly subsequent to the corn popping process, and comprising a chamber containing the corn kernels to be popped and having a cover with a recess in which is disposed a butter container, whereby the butter in the container is heated by the same microwave source as the kernels and consequently is melted during the popping process.

Radio frequency energy combiner or divider

Abstract: of the Disclosure Circuitry for dividing radio frequency energy between a plurality of loads is shown in one embodiment to consist of particular printed transmission lines and isolating resistors on a common substrate, each one of such lines forming a path between an input port to which radio frequency energy is applied and a different one of a plurality of output ports to which the loads are connected. Circuitry for amplifying radio frequency energy from a source thereof is shown in the second embodiment to consist of dividing circuitry such as is shown in the first embodiment, a field effect transistor connected to each output port to amplify each portion of the divided radio frequency energy and dividing circuitry such as is shown in the first embodiment, such circuitry being connected in a mirror fashion to the field effect transistors to combine the amplified portions of the radio frequency energy at a single port. The lengths of printed transmission lines in the second embodiment are all equal.

Fresnel focussed imaging system

Abstract: An imaging system, particularly useful for acoustic medical diagnosis of a human subject, utilizes an array of radiating elements or sonic transducers located side-by-side and positioned along the subject. Signals received by the transducer are applied to a pair of pattern generation circuits which weight the individual signals by factors of +1, -1 or 0. Graphs of the weighting factors as a function of transducer location have the likeness of cosinusoidal and sinusoidal Fresnel patterns, these patterns being produced by the two circuits. Upon reception of signals, the weighted signals of each pattern are summed together, multiplied by cosinusoidal and sinusoidal reference signals and then summed together to provide a radiation pattern which converges from the array to a focal point in front of the array while eliminating a diverging pattern from a virtual focus behind the array. For transmission, sinusoidal and cosinusoidal signals are weighted by the Fresnel factors, summed together and applied to the transducers.

Method of operating pulse radar

Abstract: A method, and exemplary apparatus for practicing the method, is shown for operating a pulse radar to allow the radar ambiguity function of such radar to be modified by controlling the range and Doppler ambiguities due to the pulse waveform of such radar.

Cordic FFT processor

Abstract: An apparatus for performing a Fourier transform using Cordic techniques. Digital words are pipelined through serial add/subtract stages to provide vector rotations without trignometric lookup tables or multiply operations. The throughput of an FFT butterfly calculation is increased over prior art digital processors. A plurality of apparatus may be pipelined in a system to further increase the throughput rate. Also, the apparatus may be programmed to perform vector rotations through a plurality of angles thus providing the capability to compute FFT's of varying numbers of points.

Bit reversing apparatus

Abstract: Apparatus is disclosed for reversing the bit order of a selected portion of a digital word. A first shifter is provided to shift the position of the unselected portion of the digital word to a set of terminals. The digital word, in bit reversed order, is coupled to an adjacent set of terminals. The two sets of terminals are fed to a second shifter which couples to the output thereof the digital word with the selected portion thereof in bit-reversed order. Such apparatus is adapted for use in addressing an FFT processor adapted to operate with different batch sizes to retrieve calculated frequency components in ascending order of frequency.

Modulated carrier amplifying system

Abstract: MODULATED CARRIER AMPLIFYING SYSTEM Abstract of the Disclosure A system providing linear amplification of a signal including a pulse duration modulation of the signal upon a carrier signal, the system further including a plurality of amplifying units which are sequentially activated by the modu-lated carrier. The amplifying units are arranged in the form of a bridge circuit, the nodes of which are coupled to a load, the amplifying units including transistors which are driven alternately in states of conduction and nonconduction for maximizing power coupled to the load while minimizing power dissipated in the transistors. A filter connected between the amplifying units and the load attenuates signals at the fre-quency of the carrier so that the waveform of the signal applied to the load duplicates the waveform of the signal at the input of the system.

Profile design for distortion reduction in microwave field-effect transistors

Abstract: Profile shaping can reduce third-order intermodulation distortion in microwave f.e.t.s. The mathematical form of the profiles to accomplish this has been derived. It is shown that two forms are possible, one corresponding to a doping spike, the other to an inverse cubic decrease in doping with distance from the episurface. The first has been approximated by workers in the field. The second is believed to be novel.

Multiple buoy launcher

Abstract: A launching tube accommodates sonobuoys of differing lengths for individually launching the sonobuoys. Compressed gas modules located between the sonobuoys are individually activated by electrical signals to expel respective sonobuoys from the launching tube. Electrical contacts on the modules engage electrically conducting guides on the inner surface of the launching tube whereby the electrical signals are communicated individually to respective ones of the modules.

Correction circuit for wide bandwidth antenna

Abstract: In a radar system employing an array antenna and microwave circuitry coupled thereto for developing sum and difference signals, a correction circuit utilizes the sum and difference signals for providing increased accuracy to elevation and azimuthal angle measurements of wide bandwidth radar signals. A correction is applied to the difference signal by subtracting therefrom a weighted time derivative of the sum channel, the weighting being proportional to the boresight error slope and the sines of the elevation and azimuth angles.

Process for forming polymeric paraxylylene coatings and films possessing improved oxidation resistance

Abstract: Polymeric paraxylylene coatings and films possessing significantly improved oxidation resistance, particularly at elevated temperatures, are disclosed as well as a process for their preparation wherein certain antioxidants are vaporized and codeposited with vaporous poly(paraxylylene) precursors onto a substrate.

High information density laser image recording method and apparatus

Abstract: An optical memory for storing human readable pictorial information and machine readable digital information within the same format together with a method and apparatus for recording such information. In accordance with the invention, information is formatted as human readable imagery with the machine readable digital data being stored as picture elements of the image. In accordance with a presently most preferred embodiment, each of the many picture elements (pixels), which together comprise the image, are formulated as a plurality of spots, the modulation level of each of which are independently controllable among several levels for recording information digitally within the picture elements, while at the same time, providing the picture elements with the proper optical density values to provide a visual analog presentation of the image. Although the invention has application in a variety of fields, it is particularly suitable for use in laser image reconstruction applications wherein it can be utilized to provide a pictorial reconstruction of an original scene while, at the same time, record, in an easily accessible manner, the full dynamic range of the information acquired about the original scene within the human readable reconstruction. In addition to storing information in both a human readable and machine readable format, the invention also provides a high information packing density capability as well as a great deal a flexibility in processing and handling information.

Utensil handle for use in microwaves

Abstract: UTENSIL HANDLE FOR USE IN MICROWAVES Abstract of the Disclosure A handle for a small appliance, utensil or other body such as a coffee maker, for example, and particularly designed to be used in a microwave environment, the handle being made entirely of material which will remain cool when subjected to microwave radiation and being constructed of a ring encircling the appli-ance body and a gripping member fixed to the ring by a rigid inseparable joint, and a compressible member between the ring and the body which allows the handle to be applied to bodies having variations in dimensional tolerances.

Marine radar including anticollision unit

Abstract: A bright display radar system having anticollision capabilities in which received signals are digitized at a rate determined by a radar range setting and displayed at a constant relatively slow rate independent of the range setting. A computer based anticollision unit operates in response to the relatively slow digitized received signals so that targets may be tracked equally well at short and long ranges. Two sets of operator actuable switches are provided for controlling the anticollision unit. A first set of switches is provided which correspond directly to the most commonly used computer operating functions. The second includes an alphanumeric keyboard which may be used to actuate subroutines stored in a physically separate read-only memory which operates only in response to the alphanumeric keyboard.

Digital frequency synthesizer

Abstract: A digital frequency synthesizer is provided for producing a signal having a predetermined frequency. Such system includes: a computer for calculating the residue of the frequency to be synthesized modulo a predetermined frequency, f LO , and the nearest modulus frequency; an intermediate frequency generator for generating an intermediate frequency signal having a frequency equal to the determined residue; a harmonic generator section for combining the intermediate frequency signal with a plurality of harmonics of the predetermined frequency, f LO , to produce a composite signal having a plurality of frequency components separated one from another by the predetermined frequency, f LO , one of such produced plurality of frequency components having the frequency of the signal being synthesized; and, a selector section fed by the composite signal and responsive to the determined nearest modulus frequency, for coupling the one of the produced plurality of frequency components of the composite signal having the frequency of the signal being synthesized to an output while rejecting the remaining ones of the produced plurality of frequency components of the composite signal.

Tubular heat exchanger

Abstract: A heat exchanger for efficiently transferring heat from a first fluid body to a second fluid body within a selected container, tank or reservoir, comprising an elongated tubular hoselike plastic body of deformable material wrapped around the container and filled with the first heated fluid, the plastic body being deformable under the pressure of the first fluid so as to conform to the exterior surface of the container whereby more efficient transfer of heat between the fluids is achieved.

Biassing the Raytheon Four-Frequency Ring Laser Gyroscope

Abstract: The non-reciprocal bias element necessary for operation of a four-frequency differential ring laser gyroscope (RLG) is the subject of this paper. Each of the three alternative bias approaches currently under consideration, namely, Zeeman bias, a magnetic mirror, and a Faraday cell, is discussed in the context of its effect on the performance of a RLG. Relevant results of a detailed model including cross-relaxation, Zeeman effect, hole-burning, pathlength controller operation, and temperature are given.

Cavity feed system

Abstract: A system for feeding electromagnetic energy into a cavity for heating material contained therein includes a radiator of the electromagnetic energy and a motorized support for carrying the radiator within the cavity by the material. The radiator is constructed of a material such as alumina providing a much shorter wavelength than that existing in the environment surrounding the material to permit the radiator to have a sufficiently small size to be inserted within the cavity. Heat may also be provided by directly heating the walls of the cavity in which case the radiator is provided with a taper for directing the electromagnetic energy into the thicker portions of the material so that all portions of the material are heated at a uniform rate. The feed system includes a support for a bladder which is useful in urging uncured rubber of a tire casing against the interior surface of the cavity for forming a rubber tire.

Coding for Random-Access Memories

Abstract: A new decoding technique is presented for correcting errors due to bit-oriented hardware failures in parallel, random-access memories. It is shown that the resulting decoder compares favorably, both in complexity and in decoding delay, with currently implemented bit-switching techniques used for the same purpose.

Bipolar monolithic integrated circuit memory with standby power enable

Abstract: A bipolar monolithic integrated circuit memory wherein a standby power enable circuit includes a pair of transistors arranged in an active pullup configuration for electrically coupling or decoupling a memory array addressing section of such memory and a ground bus selectively in accordance with a standby enable signal. The standby power enable circuit is connected between the addressing section and the ground bus to reduce the standby power required by the memory. One of the pair of transistors in the active pullup configuration is an N-P-N transistor having a Schottky barrier diode clamp formed as a part of the monolithic integrated circuit memory. The use of such a transistor in the standby power enable circuit ensures rapid switching operation of the memory.

Radiographic imaging system

Abstract: A system for imaging a subject, such as a human being, in which there has been injected a contrast agent which absorbs radiation of a predetermined frequency. The system utilizes a source of high energy radiation such as X or gamma radiation. The source is a composite of first and second radiating materials each of which is arranged in a predetermined pattern or code, each pattern having both luminous and dark regions. In one embodiment, the luminous regions of one pattern are in registration with the dark regions of the other pattern, these regions being spaced apart in an alternative embodiment. The characteristic frequencies of radiation emitted by the first and second materials are respectively lower and higher than the predetermined absorption frequency. A detector of radiation is positioned relative to the subject and the source such that radiation propagating through the subject is incident upon the detector. Since the absorption edge of the contrast agent lies between the two characteristic frequencies of radiation, radiation from the second material is preferentially absorbed by the contrast agent with the result that the contrast agent appears to be illuminated by a coded source while the remainder of the subject may be regarded as illuminated essentially by a uniform uncoded source. Imaging is accomplished by a decoding of a detected coded image. Substances within the subject having other absorption frequencies are not imaged since the radiations of both materials are essentially equally absorbed by the subject so that the source appears uncoded.

Variable size character generator

Abstract: A system for displaying, performing positioning, sizing, and performing supportive composition functions for newspaper advertising layout in which characters and symbols are displayed with a height and width closely approximating the height and width of the actual printed characters. Characters are displayed as rows and columns of dots. Preselected rows and columns are deleted or repeated to decrease or increase the size of a character from a standard fixed size. Interactive work stations position copy, edit and correct text, adjust style and point sizes, to accomplish accurate composition functions. A Bit Image Memory digitally stores all displayed patterns including the character dot patterns directly to minimize the response time of the system to operator inputs. An arithmetic unit is disclosed which produces lines which also accurately represent the final copy.