Abstract: A photoconductor comprising an optically sensitive FET in which an abrupt heterojunction (18) is inserted in the channel (11) at a certain distance from the gate contact (16). This provides a potential barrier (17, FIG. 4) in the valence band that accumulates minority carriers (carriers of the lower mobility type) and controls their release. A gate bias resistor which is conventionally used in a receiver circuit including the FET is no longer required, instead the potential barrier height determines the time constant and a response comparable in length with an input optical pulse is achieved. This overcomes the problems of integrated manufacture, and slow response, associated with the large value of the bias resistor which is needed to reduce noise.

Abstract: A radar system with auxiliary scanning provision for providing more dwell time on target, the system having a main frequency scan antenna with electronic or mechanical arrangements for auxiliary scanning. In the electronic embodiment, a space fed phased-array auxiliary antenna is provided, the radiating elements being interconnected with diode phase shifters, which are electronically actuated and synchronized to the antenna rotation. In the mechanical embodiment, a multi-sided prism arrangement in front of the antenna rotates in synchronism in a counter direction to the antenna, with auxiliary scanning data electronically manipulated for processing.

Abstract: An apparatus for automatic speech recognition includes a plurality of processors, including template processors in which there are stored templates representative of both speech and non-speech sounds. Incoming sounds are continuously converted into digital signals in respective frames representative of speech and non-speech sounds, respectively. Sequences of such frames are compared with both the speech and non-speech templates to determine the closest matches. Endpoints of respective speech utterances are determined in response to the detection of respective non-speech-speech-non-speech sequences, whereupon such speech utterances are processed to recognize the same.

Abstract: Apparatus for reducing the effects of mixer leakage in a zero IF transmission system includes first and second mixers having relatively equal leakage amounts from an oscillator port to an input port, with the input port of said first mixer adapted to receive a zero IF receiver input signal and with the output port of said first mixer capacitively coupled to the input port of the second mixer. The oscillator ports of the first and second mixers are coupled to a local oscillator output, with the output ports of said first and second mixers coupled respectively to an adder and subtractor circuit to provide respectively a DC signal indicative of the leakage and an output signal indicative of the magnitude of said input signal as effected by leakage to thereby enable the determination of said input signal after mixing.

Abstract: A device is disclosed by which a portable receptacle can be inserted onto, secured to and extracted from a stationary support. The device utilizes a pair of cooperating securing members, one of which is attached to the support and the other of which is attached to the receptacle. The securing member on the receptacle is stationary. The other securing member is movable linearly and rotatably. When the two securing members are engaged with each other, they can cooperate in connection with the insertion, securement and extraction of the receptacle.

Abstract: A self-aligned gate structure for a compound semiconductor MESFET is formed rom a lower silicon layer and an upper metal, e.g. nickel, region. The nickel region forms an etch mask for the silicon and subsequently an implantation mask for the drain and source regions. Etching of the silicon provides an undercut whereby the gate separation from the drain and source is defined. Heating the structure to anneal the implant diffuses the metal into the silicon to form a compound silicide gate structure.

Abstract: A shipboard search radar in which an antenna beam is stepped up and down in elevation to keep the beam pointed approximately toward the horizon even though the ship may be rolling and/or pitching.

Abstract: A method and apparatus for determining the orientation of the optical axis of radiometer instruments mounted on a satellite involves a star sensing technique. The technique makes use of a servo system to orient the scan mirror of the radiometer into the path of a sufficiently bright star such that motion of the satellite will cause the star's light to impinge on the scan mirror and then the visible light detectors of the radiometer. The light impinging on the detectors is converted to an electronic signal whereby, knowing the position of the star relative to appropriate earth coordinates and the time of transition of the star image through the detector array, the orientation of the optical axis of the instrument relative to earth coordinates can be accurately determined.

Abstract: There is disclosed a clamping device which comprises a U-shaped spring secured to a spring retainer in a pivotable manner. The spring retainer is a sub-assembly which consists of two plates forming a slot when sandwiched together to accommodate the spring. The two plates associated with the retainer assembly accommodate a rotatable bolt or screw which screw is directed into a compression stop assembly. A bracket is mounted to the appropriate waveguide flange. This bracket contains an aperture to accommodate a projecting end of the spring. The mating waveguide flanges are clamped in place by adjusting the captive screw which serves to deflect the U-spring completing the clamping action. The unit, as described in the specification, contains two U-shaped springs both of which are coupled to a central spring retaining unit and can operate to connect or disconnect two separate waveguide sections.

Abstract: A liquid crystal switching device includes first and second polarization reorienting cells disposed such that a polarized component of an incident light beam is incident normal to the cell.

Abstract: An apparatus for controlling data traffic throughout a communication network includes a plurality of network interface devices in each subsystem. The interface devices are substantially identical throughout the network and each autonomously controls all data traffic thereacross.

Abstract: A liquid crystal switching apparatus includes a plurality of juxtaposed liquid crystal switching devices, each such device being capable of selectively reorienting the polarization of a polarized light beam component incident thereupon.

Abstract: A passive radar ranging system having an antenna system for receiving radiated electromagnetic energy emanating from an emitter source, plus a translation resolution system and a digital computation system for making phase measurements of the received electromagnetic energy with the translated and resolved energy signals being operated upon by a plurality of system spacing parameters, the radiated energy being modulated in a particular pattern, randomly modulated or unmodulated and with the emitter source being fixed or moving while the phase measurements are made from a single measurement platform which may also be fixed or moving with respect to the emitter source, the phase measurements being employed for determining the instantaneous range from the emitter source to the measurement platform.

Abstract: A multifunction monolithic microwave integrated circuit composed of a pluity of dual gate FET amplifier sections connected between a pair of transmission lines which are adapted to receive one or two input signals. The circuit can be configured, by selective external connections and biasing voltage levels, to function in a number of different modes, such as an amplifier, a mixer, modulator, a variable amplifier, an attenuator, a temperature compensation chip, a frequency multiplier and a phase shifter.

Abstract: An optical switching device includes first and second polarization changing cells, the polarization changing cells utilize twisted nematic liquid crystal material to effect the change of polarization. The resultant device exhibits reduced cross talk between the output ports thereof and requires less voltage to effect the switching of the output beam therebetween.

Abstract: A digital tone squelch detect circuit functions to give an enabling signal for audio transmission in an FM radio network. The circuit comprises an analog to digital converter which outputs a binary coded signal representative of the voltage level of a received audio tone signal. The binary signal is then placed into a shift register which periodically is rotated and multiplied by a reference clock signal for correlation with a stored replica of the tone. The output of the correlator, which is representative of the degree of correlation, is fed to an accumulator which integrates it and sends it to a comparator where its binary valve is compared to an arbitrary threshold binary value by a hysteresis network. After detection the hysteresis established circuit outputs a tone detect signal and lowers the detection threshold so as to maintain the tone detect signal during periods of signal fadeout.

Abstract: A collimator includes a transparent base member defined by a planar surface and a spherical reflecting surface and includes an opening therein whereby an optical fiber may be terminated in the focal plane of the spherical reflecting surface.

Abstract: There is disclosed a method for determining the location of an arc or corona as occurring in a high voltage power supply. The technique utilizes sheets of sensitive photographic film which are placed between printed circuit boards of the supply or between high voltage components and the metallic chassis walls of the power supply. During supply operation if an arc or corona occurs the film becomes exposed. The amount of exposure is determinative of the magnitude of the arc as well as indicative of the location of the arc or corona discharge which location and magnitude is determined by developing the film after supply operation. In this manner a comparative analysis of the amount of corona or arc as a function of time can be made by comparing the film density after photographic chemical development. The technique enables one to, therefore, accurately determine not only the magnitude of the arc or corona discharge but the exact location of the same.

Abstract: A method of making a field-effect transistor includes performing a first ion implant in at least one region of a gallium arsenide substrate and forming a metallization layer of titanium-tungsten nitride on the implanted substrate. A metallic gold masking layer is deposited on the metallization layer over the implanted region and that portion of the metallization layer which is unmasked is removed. A self-aligned source of implantation ions is beamed into the first implanted region in those areas not covered by the masking layer. The substrate is then annealed to activate the implanted region with the gold masking layer remaining to greatly reduce the resistance of the gate electrode of said field-effect transistor.

Abstract: A data transport control apparatus including a storage medium independently accessible by a device interface controller for interconnecting the storage medium and peripherals, a communication bus control for interconnecting the storage medium and a communication bus and a microprocessor bus for interconnecting the storage medium and a microcomputer wherein all interconnections to the storage medium are effectively isolated from each other.