Showing papers by "Raytheon published in 1969"

Experiments Involving a Microwave Beam to Power and Position a Helicopter

Abstract: This paper describes two different experiments involving a microwavebeam and a helicopter. The first experiment utilized a CW microwavebeam to supply a small helicopter with all of the power that it neededfor its propulsion. The second experiment utilized an unmodulated CW microwave beam for supplying a position reference to the helicopterer with respect to roll, pitch, yaw, and horizontal translation. Thesecond experiment also involved the construction of a fully articulatedhelicopter and a complete control system carried on board theli-helicopter. The paper also attempts to relate the small scale experimentsand the present state of component technology to practical, full scalemicrowave-powered helicopter systems that can operate at altitudesof up to 50 000 feet.

Annular slot antenna with stripline feed

Abstract: A stripline antenna having a radiating aperture in the form of an annular slot provided in one of its conducting plates and a pair of orthogonal narrow strip conductor feeds disposed between its two conducting plates and terminating under the central disk formed by the annular slot. Adjustment of the relative phase and amplitude of the electromagnetic energy applied to the strip conductor feeds permits radiation from the annular slot of circular, elliptical or orthogonal linear polarizations into space or into a waveguide.

Twenty million energy product samarium-cobalt magnet

Abstract: Considerable interest has been centered around rare-earth-cobalt magnets during recent years. For the last two years we have been carrying out a research program in the general area of rare-earth-cobalt magnets. At this time, we have successfully developed a rare-earth-cobalt magnet with close to the attainable limit of magnetic properties. Our best magnets show the following properties: B^{H}c , 8000-9000 Oe; M^{H}c , 25 000 Oe; B r , 8000-9000 G; (BH)_{\max}, 16-20 \times 10^{6} G - Oe. The magnet is based on the rare-earth-cobalt compound RCo 5 , where R is samarium. Processing includes induction heat or arc melting, pulverizing to roughly domain size, compacting in hydraulic press in magnetic field to suitable shape and size, sintering, finishing, magnetizing, and stabilizing. Most of our laboratory production thus far has been ring magnets for PPM stacks of traveling wave tubes. These magnets have outperformed the best available platinum-cobalt magnets from both magnetic and thermal stability points of view in actual tube qualification tests.

Surface vehicle fleet command and control system

Abstract: A system for communicating with and locating mobile surface vehicles in a high multipath signal clutter environment such as an urban center. This system seeks to take advantage of the scattering of the CW wave in urban areas for both communication and ranging where line of sight radiation techniques may not properly function. A plurality of remote relay stations are located at fixed points throughout the urban area. Each station receives and transmits wireless coded digital data and tone burst signals, the tone burst signals being used for phase ranging. Additionally, each of the surface vehicles is equipped with a transponder. The vehicle transponder is responsive only to a radio signal having a formatted message. This includes the vehicle identification code and a ranging tone suitably impressed thereon. The formatted signal is transmitted from one of the relay stations and picked up by a preselected number of other relay stations as well as the vehicle transponder. The transponder in turn generates a reply signal containing message data and a tone burst signal in phase with the original transmitted signal.

Franck-Condon factors for band systems of molecular hydrogen. I.

Abstract: Franck-Condon factors are reported for the ( B 1 Σ + u - X 1 Σ + g ), ( I 1 Π g - B 1 Σ + u ) and ( d 3 Π u - a 3 Σ + g ) band systems of molecular hydrogen. In each electronic state, wavefunctions were computed for all vibrational levels up to the dissociation limit by numerical solutions of the radial Schrodinger equation in which the potential energy function was entered in tabular form at equally spaced intervals of 0·01 A in the range of nuclear separations r = 0–25 A. In the X and B states the potential curves were obtained by interpolation and extrapolation of Rydberg-Klein-Rees (RKR) potential data; in the I, a and d states the potential curves were constructed from the Morse formula. The resulting sets of Franck-Condon factors are given for all allowed bands of each system. It is shown that the row and column sums in these matrices do not and should not all equal unity.

Inhomogeneous Broadening of Ferromagnetic Resonance Lines

Abstract: A general theory of ferromagnetic resonance is developed assuming that the local, effective magnetic field is inhomogeneous. The scattering processes induced by the inhomogeneity may be classified as "primary" processes (which couple the uniform mode to nonuniform modes) and "secondary" processes (which couple nonuniform modes). In previous work only the primary processes were taken into account. The effect of secondary processes upon the susceptibility is calculated in the present paper. A perturbation series for the complex, effective resonant frequency of the uniform mode is derived. It is shown that the important terms of this infinite series can in part be generated by a self-consistency condition for the complex effective resonant frequency of spin waves. An approximate solution of this self-consistency condition is derived. Applied to polycrystals with cubic crystal structure, the theory predicts a linewidth of $\ensuremath{\simeq}2.07\frac{{{H}_{a}}^{2}}{4\ensuremath{\pi}{M}_{0}}$ for spherical samples and ${H}_{a}\ensuremath{\ll}4\ensuremath{\pi}{M}_{0}$ but $\ensuremath{\simeq}0.87{H}_{a}$ for ${H}_{a}\ensuremath{\gtrsim}4\ensuremath{\pi}{M}_{0}$. Here ${H}_{a}$ is the anisotropy field and ${M}_{0}$ the saturation magnetization. The off-resonance absorption is characterized by the existence of a "strong absorption" region. When the intrinsic damping of the spin waves is assumed to approach zero the absorption goes to zero in the exterior of this region but to a finite value in its interior. If the Fourier spectrum of the inhomogeneity has significant components only at long wavelength and the inhomogeneity is weak, the strong absorption region coincides with the dc field interval in which the signal frequency is degenerate with resonant frequencies of long-wavelength spin waves. With increasing inhomogeneity, the width of the strong absorption region increases by approximately twice the width of the resonance line.

Simple Procedures for Radar Detection Calculations

Abstract: The literature of radar contains results of Rice, Marcum, Swerling, and Schwartz in several families of curves, which permit radar engineersto estimate the signal energy ratio required for a given level of detectionperformance. The variety of radar problems, however, makes itimpractical to construct curves for all combinations of radar and targetparameters. The concept of detector loss is used here to evaluate lossesattributable to integration and collapsing, with an accuracy of ±0.3 dBon steady targets. This is added to a separate fluctuation loss, modifiedfor diversity effects, to obtain results on all Swerling target modelsand also on partially correlated targets. The accuracy of the combinedlosses is ±0.5 dB for a wide range of detection and false-alarm probabilities.Starting from the basic single-sample detection curves, onlythree additional graphs are needed to find the energy ratio for givendetection performance in any of these cases. Examples are given whichshow the ease with which different radar options may be compared asto performance on an arbitrary type of target.

Intraoral occlusal telemetry III, tooth contacts in chewing, swallowing and bruxism

Abstract: IT IS CRITICAL in the study of occlusion to avoid cumbersome recording devices which trigger artificial neuromuscular reactions and create artifacts which could be interpreted as being physiologic. In recent years 6 it has become possible to study the dynamics of occlusion with miniaturized electronic equipment without interfering with normal function. A telemetric system developed in our laboratory registers occlusal contact in three to five different areas on the same tooth. 8 The multifrequency transmitter device used for this purpose is small enough to fit into the space of one missing molar. Some findings regarding the occurrence and frequency of single and gliding tooth contacts during chewing and swallowing and during bruxism are presented here.

Frequency- and time-dependent gain characteristics of dye lasers

Abstract: The approach used by McCumber for treating phonon-terminated lasers is applied to investigate the gain properties of dye lasers and is extended to include effects arising from population buildup in the triplet-level system and associated triplet-triplet absorptive losses. The gain is expressed in terms of time-dependent excited-state populations and spectral emission and/or absorption functions. For a given optical-pump pulse, a computer program is used to solve rate equations for the populations up to threshold and to calculate the gain as a function of time and frequency. The gain varies with frequency over the broad fluorescence bands characteristic of dye molecules and with time until the threshold for laser action is reached. Experiments using rhodamine 6G verify the predicted dependence of the laser frequency and time of threshold on cavity Q and demonstrate laser frequency tuning by adjusting the opening time of an intracavity Q switch. No variation of laser frequency is expected for fluorescing molecules exhibiting large Stokes shifts; this is observed for 7-hydroxycoumarin. Computer calculations of the gain for anthracene and rhodamine B illustrate the dependence of gain properties on the rate of intersystem crossing and triplet-triplet absorption. An estimate of the rate of intersystem crossing for rhodamine B in methanol is obtained from a comparison of predicted and observed laser threshold conditions. Requirements for achieving flashlamp-pumped laser action are shown to depend upon both flashlamp and dye properties and are analyzed using the above approach.

Dispersive delay lines using ultrasonic surface waves

Abstract: Surface ultrasonic wave delay lines with dispersive time-frequency characteristics have been made using interdigital electrode arrays with variable element spacings on LiNbO 3 . The devices operate at 60 MHz with low insertion loss and a 3-dB bandwidth over 25 percent. A model has been devised which accurately predicts the phase and amplitude characteristics of the devices. "Weighting" the array to improve the phase characteristic is described.

A New Method for Calculating Probabilities of Errors Due to Impulsive Noise

Abstract: A new approach to the prediction of error rates in digital data transmission systems when the dominant source of errors is given by noise bursts, each having a fiat spectrum across the band of interest, is described. Specifically, a hierarchy of phaseaveraged conditional error probabilities called k th receiver impulse characteristics (RIC) are defined, which depend only on the receiver's structure. Error probabilities are then computed by averaging the RICs over the statistics of the impulsive noise which is characterized at the RF input of the receiver. To illustrate the approach in a practical, interesting situation, a detailed analysis is carried out for a phase-shift keyed system employing either a linear or a hard-limiting receiver, and for impulse rates small enough that errors are essentially caused by single impulses.

Optical second‐harmonic generation in crystals of organic dyes

Abstract: Optical second‐harmonic generation has been observed in crystals of six organic dyes. One dye, 7‐diethylamino‐4‐methylcoumarin, appears to be at least as good a frequency doubler as LiNbO3 and has a much higher resistance to surface damage.

Franck-Condon factors for band systems of molecular hydrogen—II The (C1πu-X1σ+g, (D1πu-X1σ+g) and (h3σ +g-c3πu) systems

Abstract: Franck-Condon factors are reported for the ( C 1 π u - X 1 σ + g ), ( D 1 π u - X 1 σ + g ) and ( h 3 σ + g - c 3 π u ) band systems of molecular hydrogen. In each electronic state, wavefunctions were computed for all vibrational levels up to the dissociation limit by numerical solutions of the radial Schrodinger equation using a tabulated potential energy function. In the X, C and D states, Rydberg-Klein-Rees (RKR) potential curves were used; in the c and h states Morse potentials were used. The RKR curves were constructed for energies corresponding to integral and non-integral vibrational quanta, using spectroscopic data selected from the literature. These curves were interpolated and extrapolated to prescribed dissociation limits by means of suitable power law potential formulae. The resulting sets of Franck-Condon factors are given for all vibrational bands of each system.

Method of performing digital computations using multipurpose integrated circuits and apparatus therefor

Abstract: A digital computer, exemplifying a method of organizing and controlling the elements of a general or special purpose computer, incorporating identical multipurpose integrated circuits in the control and/or arithmetic elements, each one of such circuits being responsive to the combination of commonly applied clock pulses and coded function signals and a unique enable signal. With such an arrangement, a basic design of such control and/or arithmetic elements may be changed to expand word length, memory capacity or instruction repertoire by connecting similar multipurpose integrated circuits to existing ones as required.

Radio frequency absorber

Abstract: An absorber for radio frequency energy using incombustible materials to minimize adverse effects from the conversion of such energy to heat, including a fibrous mat of nonabsorbing material in which the absorbing material is distributed in such a manner that discontinuities in the index of refraction, meaning always the electrical index, in the path of the energy to be absorbed are minimized.

Fast Fourier transforms without sorting

Abstract: This correspondence presents a mechanization of the fast Fourier transform which results in a particularly simple and compact FORTRAN program without the need for sorting the answers.

Satellite communication system

Abstract: An improved communication system using an active transponder to relay microwave signals from any one of a number of transmitting stations to selected groups of receiving stations In a preferred system the active transponder is installed in a satellite spacecraft and is arranged to convert a number of signals, in closely spaced channels, from the transmitting stations in such a manner that the bandwidth of each one of the relayed signals is increased and retransmitted without suffering from the effects of interchannel modulation

Analysis theory for the shaped-beam doubly curved reflector antenna

Abstract: An analysis theory of the shaped-beam doubly curved reflector antenna is described. The analysis computes the far-field patterns by calculating the current density distribution on the nonanalytic surface that the shaped-beam doubly curved reflector presents using the physical optics vector approximation. The presented theory utilizes a computer solution approach to achieve an accurate knowledge of the principal and cross-polarization elevation and azimuth patterns by numerically integrating the field contributions over the entire reflector surface. A comparison of the computed and measured principal plane patterns is shown.

Antenna slew system

Abstract: An antenna azimuthal positioning mechanism formed from pairs of elongated antenna supporting struts pivotally mounted on a fixed support structure and extending both outwardly and in crossed relationship therefrom to pivotally connect with an antenna whereby the antenna pivots with respect to the supporting struts as the supporting struts carry the antenna past an end of the fixed support structure to give a partial view to the rear of the support structure and thereby provide an azimuth sector scan subtending an arc which is greater than the pivoting arc of any one of the supporting struts. The supporting struts can be disconnected from the antenna to facilitate transfer of the antenna to a telescoping stowage support for antenna stowage.

Progress in the Design of Rectennas

Abstract: This paper reviews the progress in the design of rectennas which are used to collect and rectify the microwave energy at the receiving end of a microwave beam power transmission system. A new lightweight rectenna which provides 20 watts of power but weighs only 20 grams is described. Future trends in construction are discussed.

Multipath compensation system

Abstract: A system for compensating for multipath distortion in a synthetic phase isolator predetection combiner. Since echos in the signal can be detected with respect to both magnitude and sense, this information can be used to suppress echos or to control time delay compensation elements to thereby provide a more coherent output signal. Multipath distorted signals are received at a plurality of channels, each of which channels effectively shifts the input signal phase by predetection combination with the sum of the signal outputs of the other channels such that each channel output is substantially independent of the input signal phase.

Spikeless single-mode laser

Abstract: A laser structure comprising a rod-type lasing element and including means for pumping the element to produce light emission from the ends thereof. Optical means responsive to the light emission create a traveling wave of the light which passes through the rod-type lasing element numerous times to produce a single mode output beam of coherent radiation. A nonlinear light absorber interposed in the single-mode output beam path absorbs large portions of light energy in the traveling wave as the intensity thereof increases. Such arrangement is operative so as to reduce the inherent spiking of the output light beam characteristic.

Franck-Condon factors for band systems of molecular hydrogen—III: The (B'1Σ+u−X1Σ+g), (E1Σ+g−B1Σ+u), (G1Σ+g−B1Σ+u) and (k3Πu−a3Σ+g) systems

Abstract: Frank-Condon factors are reported for the ( B ' 1 Σ + u − X 1 Σ + g ), ( E 1 Σ + g − B 1 Σ + u ), ( G 1 Σ 1 g − B 1 Σ + u ) and ( k 3 Π u − a 3 Σ + g ) band systems of molecular hydrogen. In each electronic state, wavefunctions were computed for all vibrational levels up to the dissociation limit by numerical solutions of the radial Schrordinger equation using a tabulated potential energy function. In the X , B and B ' states Rydberg-Klein-Rees (RKR) potential curves were used; in the E , G , a and k states Morse potentials were used. The RKR curves were constructed for energies corresponding to integral and non-integral vibrational quanta, using spectroscopic data selected from the literature. There curves were extrapolated to prescribed dissociation limits by means of suitable power law potential formulae. The resulting sets of Franck-Condon factors are given for all vibrational bands of each system.

Optical scanning device

Abstract: An optical scanning system embodying a rotatable drum having a series of mirrors arranged along its inner surface, a focusing lens system for directing an image onto an angled mirror located within the drum and on the axis of the system, the angled mirror directing the image onto the series of mirrors on the drum, the mirrors in the series being tilted at successively greater angles whereby as the drum rotates each mirror will effectively perform a line scan of said image directing the radiation from successive points along said scan toward a rotating mirror mounted on a galvanometer adjacent the axis of the rotating drum, the rotating mirror directing said scan to a remote detector.

Spherical acoustic transducer

Abstract: A spherical acoustic transducer formed from electromechanically active material and having a common electrode attached to one surface as a voltage reference and a distribution of electrodes attached to other surfaces so that the radial and circumferential vibrating modes of the acoustically excitable sphere are detectable and resolvable as to bearing angle over 4 pi steradians.