Abstract: A circuit for generating chaotic signals implemented using heterojunction bipolar transistors (HBTs) and utilized in low probability intercept communications. The HBT chaotic circuit generates truly random analog signals in the GHz range that are non-repeating and deterministic and may not be replicated by preloading a predetermined sequence. A fully differential autonomous chaotic circuit outputs two pairs of chaotic signals to be used in a communication system. As it is impossible to generate identical chaotic signals at the transmitter and receiver sites, the receiver itself sends the chaotic signal to be used for encoding to the transmitter. The receiver includes a chaotic signal generator and digitizes, upconverts, and transmits the generated chaotic signal to the transmitter. The transmitter uses the received chaotic signal to code data to be transmitted. The receiver decodes the transmitted data that is encoded by the chaotic signal to retrieve the transmitted data.

Abstract: A circuit for generating chaotic signals implemented using heterojunction bipolar transistors (HBTs) and utilized in low probability intercept communications. The HBT chaotic circuit generates truly random analog signals in the GHz range that are non-repeating and deterministic and may not be replicated by preloading a predetermined sequence. A fully differential autonomous chaotic circuit outputs two pairs of chaotic signals to be used in a communication system. As it is impossible to generate identical chaotic signals at the transmitter and receiver sites, the receiver itself sends the chaotic signal to be used for encoding to the transmitter. The receiver includes a chaotic signal generator and digitizes, upconverts, and transmits the generated chaotic signal to the transmitter. The transmitter uses the received chaotic signal to code data to be transmitted. The receiver decodes the transmitted data that is encoded by the chaotic signal to retrieve the transmitted data.

Abstract: An atomic frequency standard is disclosed where optical pumping of the resonance cell is achieved by coherent light and the pumping results in Coherent Population Trapping of the resonant alkali metal atoms. The fabrication of frequency standards of substantially reduced size and weight is permitted by use of solid state laser sources having certain integrated optical modifier elements and a resonance cell of metallic construction.

Abstract: The invention disclosed herein is a cell construction for use in optically activated atomic frequency standards. The cell includes a stiff non-magnetic metallic chamber body having an integral cold weldable tubulation through which the atomic source material may be charged and the tubulation pinched off to seal the chamber. Optically transparent windows for introducing light radiation into the chamber and receiving light signals generated therein are sealed to the chamber.

Abstract: A method for hydrogen treatment of FETs for use in hermetically sealed packages is disclosed. FETs such as GaInAs HEMTs are treated before hermetic packaging by heating them in a hydrogen atmosphere until their drain currents degrade, and then continuing to heat them until their drain currents are restored. The HEMTs' drain currents are monitored and the process is continued until the currents stabilize. Thereafter the devices' temperature is lowered to the desired operating temperature and their drain currents are measured. If the drain currents after treatment are close enough to the current levels before treatment, the devices are selected; otherwise they are rejected.

Abstract: A wood adhesive composition including an effective amount of a phenol-formaldehyde resin; and a modifying agent which agent renders the composition capable of bonding to a hard wood.

Abstract: A channel layer, donor layer, Schottky layer, and cap layer are formed on a substrate. A source and drain are formed on the cap layer. A gate is formed on the cap layer, or at the bottom of a recess which is formed through the cap layer and partially extends into the Schottky layer. The donor and Schottky layers are formed of a semiconductive material which includes an oxidizable component such as aluminum. A passivation or stop layer of a lattice-matched, non-oxidizable material is formed underlying the source, drain, and gate, and sealingly overlying the donor layer. The stop layer may be formed between the Schottky layer and the donor layer, or constitute a superlattice in combination with the Schottky layer consisting of alternating stop and Schottky sublayers. Alternatively, the stop layer may sealingly overlie the Schottky layer, and further constitute the cap layer.

Abstract: A surface acoustic wave (SAW) diffraction-effect or interference-effect device with a highly isotropic substrate having a high coupling coefficient and low attenuation losses. The use of X-propagating rotated-Y-cut lithium niobate as the SAW substrate, with the Y rotation angle selected at 121 degrees, provides a practically isotropic material, with a high coupling coefficient and relatively low attenuation losses.

Abstract: A protective shroud (22) for a flexible electrical cable (20) at the location where it emerges coaxially from the rear end (14) of an electrical device, such as an inductive proximity or photoelectric sensor (2), serving as a strain relief and protection from being bumped as well as retaining such electrical cable (20) at a gradual right-angle bend from a horizontally-mounted sensor (2) to keep it out of the way, such as from the aisle adjacent a conveyer on which the sensor is mounted. Snap-in means including an annular groove (18) on the rear end of the sensor (2) and a constricted-opening (22f) slot (22e) in the inner side wall (22d) of the shroud (22) afford snap-in mounting of the latter onto the rear end (14) of the sensor (2) with the shroud (22) being rotatable thereon to allow the electrical cable (20) to be oriented in any desired direction. Another version of protective shroud (24) adapted for a vertically-mounted sensor ( 2) in FIG.

Abstract: A surface acoustic wave (SAW) device configured to operate as a spectrum analyzer, and having an array of input transducers disposed on a substrate in such positions as to produce a focused beam of acoustic energy at a focal arc, each position on the arc being representative of an input signal frequency. Output transducers produce electrical signals corresponding to the energy received at successive segments of the focal arc. The disclosed device includes various combinations of input transducer array improvements, some of which are to provide amplitude weighting of the input array, including aperture width weighting, capacitive weighting, resistive weighting, series-parallel weighting, and source withdrawal weighting. Another improvement in input array configuration eliminates close or overlapping electrodes of opposite polarities and thereby reduces parasitic capacitance and acoustic radiation between electrode elements.

Abstract: A battery-powered thyristor-controlled lift truck traction motor control system includes simple and economical means for providing plugging torque in a continuous or proportional manner. A dual-motor drive system disclosed allows series motors to be operated in parallel from a single thyristor control system during both acceleration and plugging conditions, and allows the two motors to be operated at widely different speeds without large currents circulating between them.