Abstract: A supergate having an enabled differential input, a single ended input and a differential output provides high speed communication between electronic cards in an electronic device. The enabled differential input is input to a differential amplifier which is electrically driven by a current source. A differential AND gate having the single ended input as an input is electrically driven by one output of the differential amplifier and provides the differential output. The other output of the differential amplifier is OR'd with one side of the differential output so that the propagation delay for the enabled differential input is essentially the same as that for the single ended input. Current steering is used to provide high speed signal flow through the differential amplifier and the differential AND gate.

Abstract: A signal generator for producing a triggered output signal of digitally controlled phase and frequency includes a skewing circuit for producing an output clock signal of the same period, T, as an input, triggered reference clock signal but which is phase skewed from the reference clock signal by a phase angle, P, of 0 to 360 degrees as determined by input digital data. The skewed clock signal is frequency divided by an integer factor N, and a timing circuit counts reference clock periods to initiate frequency division a programmable delay time (J.times.T seconds) following triggering of the reference clock signal, where J and N are integers also determined by input digital data. An AND gate qualifies the frequency divided skewed clock signal with the skewed clock signal itself to produce a periodic output signal of digitally controlled frequency N/T, the first pulse of which is delayed following triggering of the reference signal by a digitally controlled interval of (T.times.J)+(P.times.T/360) seconds.

Abstract: A probe for use in electrical circuit test equipment, in which a contact element is longitudinally slidable in an insulator sleeve which also contains an R-C attenuator circuit connected electrically to the contact element by an electrically conductive elastomeric material. A high impedance cable is connected electrically to the other end of the RC attenuator circuit by another piece of conductive elastomeric material. The cable connects the attenuator to another R-C circuit which, together with the attenuator, forms a voltage divider, and the attenuated signal controls an amplifier which provides a signal through a low impedance cable to a test equipment.

Abstract: Suppression of radiated harmonics in a single stage transistor oscillator and transmitter circuit is achieved by inserting a narrow band filter, such as a surface acoustic wave resonator (SAWR), in the oscillator signal feedback loop at the point of emissions of the harmonics.

Abstract: A multiplexer samples multiple analog waveform signals to provide a sequence of input signals to an active low-pass filter. The bandwidth of the filter is determined by an input RC network having series resistance and shunt capacitance elements. As the multiplexer switches state to sample a different analog signal, the resistance elements of the filter are temporarily shorted to allow the filter input signal to rapidly charge or discharge the shunt capacitance element to a steady state voltage in response to any change in input signal voltage. The resistance elements are then unshorted to permit normal low-pass filter operation. Switch means are also provided to selectively disconnect the shunt capacitance element from the network when the resistance elements are shunted, thereby selectively widening the bandwidth of the filter to pass higher frequency input signals.

Abstract: Integrated capacitors provide more than one capacitor on a single dielectric substrate. A dielectric substrate has a conductive backplane on one side and two or more conductive capacitor plates on the opposite side. The integrated capacitors may be mounted on a shield wall which has a through hole so that one capacitor is connected to the shield wall and another forms a coupling capacitor via the hole between two stages on opposite sides of the shield wall.

Abstract: A switch closure test method and apparatus is disclosed in which switch position information in the form of logic signals indicative of switch closure status of a plurality of switches is arranged in a predetermined waveform display format for simultaneous viewing.

Abstract: A frame capture circuit for use with a video camera includes an analog-to-digital converter for converting composite video to digital form and a memory for storing sequential frames of digital video. The analog-to-digital converter is connected to the memory through a summer, and the memory has an output connected to a second summer input through a feedback loop. The feedback loop includes a switch controlled by a central processing unit such that when the switch is closed, the output of the memory is a composite video data frame comprising a current plus a previous frame of data. The central processing unit closes the switch whenever an event of interest displayed on an external device falls near the end of a frame of video generated by the camera so that the entire event is captured without regard to the scanning phase of the video camera.

Abstract: A reverse current transmitted through an initially forward biased step-recovery diode causes the step-recovery diode to switch from the forward biased state to a reverse biased state, thereby developing an abruptly rising reverse bias voltage across the step-recovery diode. The abruptly rising reverse bias voltage is applied across a series combination of a capacitor and a laser diode, connected in parallel with the step-recovery diode to force a short, abrupt forward current pulse through the laser diode, thereby causing the laser diode to emit a short optical pulse.

Abstract: A graphics display terminal performs a pan operation with respect to a view motion center to effectuate spherical panning, thereby providing perspective and non-perspective views. Three dimensional instructions stored in terminal memory are re-transformed in accordance with a panned direction. Also a zoom feature is provided so that displayed images may be magnified as desired.

Abstract: An electro-optic sampler comprises a body of semiconductor material that can be energized to emit polarized light, a photodetector device for generating an electrical output signal representative of the intensity with which light polarized in a predetermined manner is incident on the photodetector device, and a body of electro-optic material defining an optical waveguide for transmitting light from the source of polarized light to the photodetector. First and second electrodes are provided for establishing an electrical field within the body of electro-optic material. The body of electro-optic material has a spherical index ellipsoid when the first and second electrodes are at the same potential and otherwise has a non-spherical index ellipsoid.

Abstract: A method for determining the thermal characteristics of a semiconductor packaging system is provided which uses a platinum resistor test unit. The platinum resistor is preferably sized to approximate the dimensions of the semiconductor device for which the package was designed, and is installed within the package. The packaged resistor is then thermally calibrated at a plurality of temperature levels to generate a linear temperature versus resistance graph or equation corresponding thereto. Next, voltage is applied to the packaged resistor causing such resistor to "self heat." Its resistance is calculated, and the temperature corresponding thereto is obtained from the graph or equation. Such temperature is the surface temperature of the resistor. This temperature may then be used to calculate the temperature gradient from the inside of the package to any reference point on or near the outside of the package, the temperature of which has been previously determined.

Abstract: A programmable microwave attenuator includes coax to slab line connectors which use rigid pin inner conductor captivation at an inner conductor interface surface within the confines of the coaxial outer conductor to improve mechanical reliability and reduce frequency dependent insertion losses. Narrow gaps between the edges of the slab line inner conductor and the coaxial outer conductor reduce unwanted modes of microwave energy transmission by concentrating the electric field at the edges of the slab line inner conductor before it emerges from the coaxial outer conductor into the slab line. A similar gap exists between the edges of the slab line inner conductor and the slab line outer conductor so that unwanted modes of microwave energy transfer are minimized after the outer conductor interface surface.

Abstract: A viscoelastic and ink-immiscible fluid is used to form a membrane over the ink orifice of a drop-on-demand, pressure pulse ink jet head. The membrane lies in a plane perpendicular to the direction of emission of ink drops, and provides a barrier between the ink orifice and the external atmosphere. Evaporation of the ink, or entry of contaminants including air into the ink, is thus inhibited. The elimination of evaporative clogging then permits the use of a smaller orifice. Wetting of the exterior surface of the ink jet head by the flow of ink through the ink orifice is also inhibited, thus making possible the production of more uniform ink drops that will emerge in a constant direction. The elastic property of the membrane permits the passage of an ink drop therethrough, followed by the closing up of the membrane.

Abstract: A multi-layer metallization method and structure that permits the use of sodium-ion contaminated titanium-tungsten (Ti:W) as a barrier metal with gold conductor metal on a silicon substrate, without significant degradation of device characteristics. After depositing the barrier and conductor metal layers, a layer of phosphorous-silicate glass (PSG) is anisotropically-etched to expose the field oxide and top surface of the conductor metal but leave PSG layer on each sidewall of the metallization structure. The circuit is then annealed at 400.degree. C. for 30 minutes. Then, an adhesion layer (Si.sub.3 N.sub.4) and an insulative layer (SiO.sub.2) are deposited over the metallization structure and field oxide, with the adhesion layer in contact with the top surface of the conductor metal and the gettering composition.

Abstract: An encoder circuit converts a thermometer code into an equivalent adjacent binary code wherein only a single bit is changed to minimally increment or decrement the value of the binary code. The encoder logic is grouped so that the state of any single bit of the thermometer code can affect the state of one and only one bit of the binary code whereby when any least significant thermometer code bit is at an invalid logic level, the invalid level is propagated through the encoder circuit to only a single, least significant binary code bit, without the introduction of any logical errors. The invalid binary code bit is then stabilized to a valid level by one or more latches.

Abstract: A combined digital-to-analog converter and latch memory circuit (10) includes an R-2R resistive ladder network (12) and a current-controlled latch memory 18. The R-2R resistive ladder network has plural input nodes (100 and 102) and an analog signal output (104). Each of the input nodes corresponds to a different bit of a digital word that is to be converted to an analog signal. The current-controlled latch memory includes plural subcircuits (14 and 16). Each of the latch subcircuits uses an amount of current to store the logic state of the bit of the digital word and to derive directly the node of the R-2R resistive ladder network. This configuration promotes the efficient use of space, power, and circuit elements.

Abstract: A resonance compensated unity voltage gain amplifier comprises an input stage and an output stage connected in feedback to the input stage and a series resonance circuit for compensating for the resonance of the output and input stages created by the feedback. Reactance of the series resonance circuit is adjusted to be substantially zero at the resonant frequency of the amplifier. The resonance compensated amplifier is incorporated into a gain selectable amplifier. The resistance on the output stage of the amplifier across which the input voltage is applied via the output voltage may be selectively varied to change the current gain of the amplifier.

Abstract: An integrated circuit is mounted on the front face of a substrate of dielectric material and the substrate is fitted in an aperture that extends through a circuit board. The substrate has contact elements distributed about the periphery of its front face, and the circuit board has corresponding contact elements on its front face distributed about the periphery of the aperture. A first clamping member is positioned at the back face of the circuit board so as to extend over the aperture in the circuit board. The first clamping member is made of thermally-conductive material and is in thermally-conductive contact with the back face of the substrate. A second clamping member is positioned at the front face of the circuit board and extends at least partially over the peripheral area of the front face of the substrate. A resilient member is effective between the second clamping member and both the substrate and the circuit board.

Abstract: A twisted nematic liquid crystal material used in a dual-frequency addressable liquid crystal cell is disclosed. Specific materials include an eutectic mixture of 2-5 monoester compounds having the formula R--X--Y--CO.sub.2 --Z--R', wherein R and R' is a straight alkyl having 2-7 carbon atoms and where each of X, Y and Z is a phenyl or trans-cyclohexyl and at least one of X, Y and Z is a trans-cyclohexyl. Also included are up to 25 weight percent of dopants to reduce viscosity and up to 10 weight percent of additives to lower the cross-over frequency, the additives being of the formula: ##STR1## wherein X is selected from the group consisting of: ##STR2## wherein R is a straight alkyl having 2-7 carbon atoms.