Abstract: In an optical data bus system, a fail-safe optical repeater-amplifier assly is provided by light energy amplifying means connected in the data bus for developing gain of signal strength for light signals transmitted along the data bus in a known direction. The light energy amplifying means is connected in parallel with a passive, non-amplifying light path, the light path having an optical length for impressing a delay on light signals passing therethrough which is substantially equal to the optical delay imposed by transmission through the light energy amplifying means.

Abstract: A rotary power transmitting shaft decoupling device has a driving element sposed coaxially within a driven element and keyed thereto by a plurality of rollers held in aligned grooves and slots of the driving and driven elements, respectively, by an indexing ring that is coaxial with and surrounds the driven element. Actuation to effect decoupling is effected by arresting rotation of the indexing ring until the rollers become aligned with slots in the ring through which the rollers are ejected.

Abstract: A self-multiplexing antenna comprising an array of radiating elements for diating a plurality of orthogonal beams in response to wave energy excitations applied thereto. A plurality of first transmission lines are connected between respective radiating elements and respective resistive terminations. A plurality of second transmission lines are connected between respective input ports and respective resistive terminations. A plurality of directional couplers couple wave energy from each input port to each radiating element in the array via the first and second transmission lines whereby wave energy from each input port generates a separate orthogonal beam from the array of radiating elements.

Abstract: A beamforming apparatus is provided for processing the outputs of a linear rray of spaced apart receiving elements. The beamforming apparatus includes a surface acoustic wave device which has a pair of transducers mounted on a substrate in a spaced apart relationship. Each transducer is capable of receiving and converting an electrical chirp signal into an acoustic signal for propagation across the surface of the surface acoustical wave device. A plurality of taps are mounted on the substrate in a spaced apart relationship between the pair of transducers for receiving, sharing and converting the acoustic signals back into electric signals. Each tap is adapted to receive a bias voltage. A device is provided for mixing the signal from each tap with a signal from a respective receiving element so as to produce a plurality of mixed output signals, and another device is provided for summing the mixed output signals so as to provide a summed output signal.

Abstract: A raster generator for producing a raster-type display on a random scan dlay terminal where the raster can be oriented at any selected angle of rotation. The rotating raster generator responds to a digital input signal representing the desired angle of rotation which may represent, for example, the turning or rolling motion of a vehicle. The generator operates digitally to provide an output comprised of two sets of digital signals, each signal set representing an axis rotated in an amount directly related to the value of the input angle. The signals are presented as inputs to the deflection coils of a cathode-ray tube (CRT) or like display.

Abstract: A rotary power transmitting shaft decoupling device has a driving component xially aligned with a driven component and keyed thereto by a plurality of force transmitting elements held in operable relation to the driving and driven components, respectively, by an axially shiftable slide element that is coaxial with the driving and driven components and is provided with a lead screw. Actuation to effect decoupling is effected by engaging the lead screw with a plunger so that rotation of the device results in axial shifting of the slide element and withdrawal of the force transmitting elements from operable relation to the driving and driven components.

Abstract: A method and apparatus for determining the presence of partial discharge ivity (corona) which makes use of corona current signals in the 20 MHz to 50 MHz frequency range and provides for identification of the corona source in a capacitor matrix. A current probe coupled to the high potential side of the capacitor detects corona discharge current signals that are fed to a bandpass filter which passes signals in the frequency range of 20 MHz to 50 MHz. The signals from the bandpass filter are amplified and integrated to provide a d.c. level proportional to the corona activity. The d.c. level signal is encoded by a voltage controlled oscillator and then converted to light. A fiber optic link transmits the converted signal to a remote console where the encoded light is reconverted to a d.c. level signal which can be displayed as an analog signal as well as activating an audio or visual alarm.

Abstract: An apparatus for frequency stabilizing a microstrip oscillator using an integrated diplexer as a frequency discriminator. The crossover frequency of the microstrip diplexer is used in a feedback arrangement to stabilize a millimeter-wave oscillator. The diplexer is coupled to the output of the oscillator and detects a shift from the desired oscillator output frequency. This shift in frequency is converted to a voltage for controlling the varactor tuning element of the oscillator to thereby return the oscillator to the desired operating frequency. Means are also provided for sensing a temperature change in the diplexer and for insuring that the oscillator output frequency is maintained at the desired frequency regardless of this temperature change.

Abstract: A wideband whip antenna is fabricated by a method which enables the antenna o have a thinner profile, be lighter in weight, and much more flexible in that the radiating conductors are mounted in a plastic antenna core in a manner to be movable freely longitudinally therein when doubled without damage to their electrical continuity.

Abstract: An apparatus is provided for processing the outputs of a two dimensional nar array of spaced apart receiving elements. The receiving elements are grouped and spaced apart in rows, which may be horizontal and vertical however, the rows may be in other directions provided they lie within a plane. The apparatus includes a plurality of surface acoustic wave (SAW) devices, each SAW device corresponding to a respective horizontal row of receiving elements and being capable of producing a plurality of horizontal phase shift outputs which linearly correspond to the number and horizontal spacing of receiving elements in a respective horizontal row.

Abstract: An antenna feed for decreasing the scan modulation of the radiated signal a radar which tracks by the method known as scan-with-compensation. The antenna feed is comprised of a coaxial line fed dipole located on the axis of a circular waveguide for radiating a single on-axis unmodulated pencil-beam during transmission. The antenna feed further comprises two parallel radiators located equally distant and on opposite sides of the transmitting circular waveguide radiator and functions during reception only. Rectangular waveguides connect the two parallel radiators with the central radiator so as to give rise to orthogonal signals in the central radiator upon reception of echo signals. An ATR tube connects the dipole to the central axial waveguide during transmission and isolates it during reception. The radiating dipole is mounted so as to remain fixed while the central circular waveguide and the two parallel reception waveguides rotate during scanning.

Abstract: An adaptive detector comprises an adaptive linear prediction filter (ALPF) nd a detection processor.The adaptive filter comprises an input filter, adapted to receive an input signal x(k) and delay it by a time .DELTA.. An L-point, or L-tap, adaptive filter has an input connected to the output of the input filter, a signal r(k) appearing at the output of the filter. A means for summing has two inputs, one for receiving the signal x(k) and the other for receiving an inverted signal from the adaptive filter, the output of the summer being an error signal .epsilon.(k). A feedback amplifier, whose input is connected to the output of the summer, takes a portion 2.mu., of the output signal .epsilon.(k) and feeds it back to the adaptive filter, thereby modifying the tap weights of the adaptive filter.The detection processor comprises a circuit, whose input is connected to the output of the adaptive filter, to receive the signal r(k), for performing a K-point discrete Fourier transform (DFT) on the signal r(k).

Abstract: An electro-optical modulator/antenna operates in the tunable diffraction ting mode to vary the magnitude of the zero diffraction order and consequently transmits optical information. A relatively thin slab of lithium niobate or equivalent electro-optic material has its lateral surfaces optically polished and its C-axis, or optical axis, running parallel to the polished lateral surfaces. At least one set of interdigital metallic electrodes are deposited on the face or just within the lateral surfaces to form, among other things, a diffraction grating that is orthogonally disposed with respect to the C-axis. When a potential source is coupled to the interdigital electrodes, the electric fields between adjacent electrodes change the crystal's index of refraction in accordance with the linear transverse Pockel's effect.

Abstract: A purge valve for full face masks or helmets includes a base member fixed the mask wall and having passages opening in a flat, annular valve seat surface. A manually operable valve member includes an outer cylindrical wall, an inner cylindrical wall reentrant from an end wall and is axially slidable on a stem extending from the base member against the action of a compression spring nested between the cylindrical walls.

Abstract: A vertical drive mechanism is provided for a cutting apparatus. The cutting pparatus can be used for in place machining of a valve seat which may include an annular turntable adapted to be rotatably mounted on the valve above the valve seat. A feed shaft is mounted through the turntable so as to be rotatable therewith, and a bottom of the feed shaft is adapted to receive a cutter for machining the valve seat. The vertical drive mechanism is mounted on the feed shaft and includes a nut threaded on the feed shaft and a gear combination. The gear combination may include a first portion which is fixedly connected to the nut, a second portion which operatively engages the first gear portion, and a third portion which operatively engages the second gear portion, the third gear portion being mounted for rotatable slidable friction engagement about the nut.

Abstract: A signal to be filtered is applied to a commutating filter which is contred by a tunable oscillator tuned to a desired filter frequency. The commutating filter includes a plurality of RC networks to which the input signal is sequentially connected. The output of the commutating filter is a series of discrete voltages from the capacitor sections and of the RC networks which are fed to an analog to digital converter. The resulting digital words produced by the converter are stored in a microprocessor and used to compute the spectral content of the input signal by means of the Discrete Fourier Transform. The computed output from the microprocessor represents the effect of the cascaded filter sections of the system.

Abstract: A liquid barrier contact to InP made of 40% tartatic acid and 30% hydrogen peroxide in a 3:1 ratio by volume is used for capacitance-voltage carrier profiling to large voltages (>10 V) on relatively heavily doped material (>10.sup.17 CM.sup.-3) and at room temperature.

Abstract: A condition responsive line array cable having pairs of conductor contain, hollow braided strands plaited into a hollow braid in which transducer mounts are enmeshed and gripped. The mounts comprise a rigid plastic tubular housing in which a rubber jacketed transducer is resiliently suspended by elastomeric projections. Resiliently flexible, hollow, tapered, rubber fairings extend from each end of the housing and are slit to admit wires pulled from a cable strand. The fairings are long relative to the housing diameter and are retained assembled with the housing by cooperating ribs and grooves.

Abstract: A technique for simulating the thermal appearance of objects. Electrical rgy is applied to conductive material that is attached to a mounting surface shaped in the form of the selected object. The conductive material is placed to simulate the radiation pattern that the object has been shown to demonstrate.

Abstract: 2.