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.

Abstract: A suspension system for an air-dropped sonobuoy includes a transducer housing wherein the upper portion is emptied upon deployment of a float. The weight distribution of the transducer and housing provides for a center of mass and a center of buoyancy at a location beneath a pivot in the upper portion of the housing. A suspension line connects the pivot with the float, and a pair of opposed extensible fins at the top of the housing locate the center of hydrodynamic pressure at the pivot. Thereby, the housing is maintained in a stabilized vertical attitude during descent through the water and during deployment at a predetermined depth independently of a difference in velocity of fluid movement at the float and at the sonobuoy.

Abstract: A transducer housing for an air-dropped sonar transducer includes a smooth cylindrical case for stowage on board an aircraft. The case is formed with a separation device which permits ejection of the transducer from the case upon impact with the water of the ocean, the device being formed of tabs on the case and chamfers on a cover plate of the case. The impact of the water on the cover plate is directed by the chamfers against the tabs to spread them apart thereby releasing the cover plate and the transducer. Pins on the cover plate project through apertures in the tabs and press against the side of the apertures with a preset force to essentially lock the tabs to the plate until the preset force is overcome by the water impact.

Abstract: A spectrometer for measuring the spectra and concentration of airborne chemicals at long ranges wherein the optical signals may be occluded by dust. A single lasing medium is utilized both for producing a transmitted optical signal and for amplifying a received optical signal, the frequencies of radiation of the transmitted and received optical signals being offset as the radiation propagates to a distant reflector and back to the lasing medium. The frequency offset is obtained by sweeping the transmitted frequency at a rate commensurate with the round trip propagation time whereby the offset is sufficient to place the received frequency at a peak at the amplifying spectrum of the lasing medium. A laser containing the laser medium further incorporates an interferometric structure within the optical path for sequentially shifting the frequency of oscillation to produce a comb spectrum for sampling the spectra of the chemicals to provide identifying signatures thereof.

Abstract: A beamformer forms a beam from a set of samples of signals from an array of elements such as sonar transducers. Sequences of signal samples from each transducer are delayed relative to each other by fractional amounts of the intersample interval. The sequences of the signal samples with the predetermined delays therebetween are applied to a common beamforming filter having a pass band of sufficient width to accommodate the signals. The impulse response time of the filter is longer than the intersample interval in any one of the sample sequences for providing a beam equal to the sum of regenerated transducer signals. The radiation pattern of the beam is independent of the sampling rate.

Abstract: An optically focussed laser radar operating with a radiation wavelength of typically ten microns is focussed on an object to be observed. Doppler data is obtained with a continuous wave signal by mixing a reference of the transmitted signal with a signal reflected from airborne scattering centers. The system is particularly useful for clear air turbulence applications wherein aerosols such as dust and pollen serve as the scattering centers for reflecting the radiation. The radar converts to a pulse Doppler system when the depth of field exceeds the desired range resolution.

Abstract: A code generation and receiving system for a large bandwidth Doppler tolerant signal for use by communication and radar systems includes a set of delay lines for producing discrete phase shifts on a carrier signal. One delay line with relatively large delays between taps thereon produces a set of quadratic phase shifts approximating a frequency sweep. A second delay line with relatively small delays between taps thereon produces a binary phase code.

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.

Abstract: A procedure for the construction of an internally vaned tube for use as a magnetron anode and as a fluid conductor in a heat exchanger. A set of copper bars is passed through longitudinal slots in a mandrel to form a set of vanes and is then enclosed by counterwound silver plated copper ribbon which forms the tube. The assembly is then brazed and cut to desired length.

Abstract: A circuit for the modulation of the frequency of radiation produced by a magnetron includes a directional coupler connected to the output port of the magnetron, a circulator coupled between the output port and a load, and a phase shifter connected between the directional coupler and the circulator.

Abstract: A communication system for coupling a set of sending stations to a set of listening stations by means of a single communication link employing time compression multiplexing of the messages transmitted from individual ones of the sending stations. A predetermined number of time slots is provided for each of sequentially occurring scans of the sending stations, each slot providing for the transmission of a preset number of data samples. CCD registers are employed with switching circuitry enabling the available slots to be assigned to stations in accordance with the average data rate of a message.

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.

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.

Abstract: A microwave heating system including an articulated waveguide arm for directing microwave energy into a subject to be heated. The articulated arm is positioned by a dual system comprising a sensor of the location of the surface being heated and a computer activated drive mechanism utilizing stored data of the form of the surface of the subject for providing a predetermined scanning path of microwave energy about the subject.

Abstract: A reflective grating for a surface acoustic wave device is formed of interleaved sets of contiguous metal strips deposited on the surface of the device. The metal in one set of the strips has a density greater than that of the acoustic propagating medium of the device while the metal of the second set of strips has a density essentially equal to that of the acoustic propagating medium of the device. Typically, a piezoelectric material such as a crystal of quartz or a crystal of lithium niobate is utilized as the base material of the device with the grating being formed of an overlay of alternating strips of gold and aluminum.

Abstract: A magnetron anode is constructed of performed blanks which are bent in two portions of which one portion is a vane and a second portion is a segment of a cylindrical surface of the anode. Alternate blanks are provided with an alternate arrangement of supports for strapping rings of the magnetron anode. The assembly of cylindrical segments is enclosed within a sleeve to which the segments are brazed to provide an air tight wall of the magnetron anode.

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. 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.

Abstract: A balanced sonar transducer comprising a front radiating mass and a rear mass coupled thereto via a ceramic transducer element which imparts vibrational motion to the front and the rear masses. The front and the rear masses are secured to a bulkhead via a tie rod which passes through the rear mass and the transducer element and is secured in the front mass. A disc spring is placed between the bulkhead and the rear mass and has a compliance of a suitable magnitude to resonate with the rear mass at a frequency which approximates the resonant frequency of the front mass with the compliance of the tie rod. The approximate matching of the resonant frequencies provides for a balancing of the stresses applied to the transducer element which insulates the transducer element from a vibrational acceleration imparted to the transducer assembly by vibrations of the ship and of the bulkhead to which the transducer assembly is affixed.

Abstract: A system for a phased array antenna including a set of power amplifiers for amplifying the power of a signal to be transmitted by radiating elements of the antenna. A set of hybrid couplers are connected between the power amplifiers and the radiating elements with individual ones of the hybrid couplers being cross-connected for sharing the power of each amplifier among a set of radiating elements. The coupling of power is selectively varied between the amplifiers and the radiating elements by shifting the phase of the signal applied to each power amplifier.

Abstract: An ink feed system for an electrophoretic printer wherein a ribbon is used to carry ink from an ink supply to the paper upon which it is applied by means of an electric field. A magnetic constituent is added to the ink and a magnetic field is impressed alongside the ribbon and parallel to the surface thereof. A Hall probe positioned in the magnetic field senses perturbations thereof perpendicular to the ribbon induced by the presence of ink on the ribbon. A signal produced by the Hall probe signals the density of the ink upon the ribbon and is utilized for regulating a flow of ink onto the ribbon.