Abstract: A new GaAs FET structure is provided by a process which provides a GaAs channel between AlGaAs layers and wherein the GaAs channel has a higher active carrier concentration than either adjacent AlGaAs layer.

Abstract: An automatic speech recognition system has a multi-mode training capability using a set of previously stored templates of a limited number of predetermined seed words to train the templates for a vocabulary of words. The training speech samples each includes a vocabulary word juxtaposed with a seed word. An averager module maintains an active average template for each of the word units of the training speech samples including the seed word units, and the active average templates are used to continuously update the seed template set as they are used in the training speech samples. The preferred training procedure employs training phrases each having a vocabulary word embedded between two seed words, and two seed template sets are used in succession, the first being composed of single-digit words, and the second composed of carrier words.

Abstract: A collector contact (6) is fabricated which is attached on the side to the collector zone (1), and around which a moat (3) is produced which laterally restricts the collector zone (1). The depth of the moat (3) is so dimensioned to be at least equal to the vertical thickness of the collector zone (1). The collector contact (6) comprises a polycrystalline silicon layer which contains dopants of the same conductivity type as the collector zone (1), and covers a highly doped contacting zone (7') which has been diffused from the adjoining collector contact (6).

Abstract: An optical lens has a blackened layer in its outer surface which extends to a depth sufficient to substantially eliminate reflected stray light in the lens. The blackened layer is formed by causing hydrogen under pressure to react for a predetermined time and temperature with a metal oxide of the optical material thereby leaving the metal oxide in its reduced form in the lens. Some of the oxides are reduced completely, leaving the metal in its elemental form in the layer.

Abstract: A programmable logic array implemented with complementary insulated-gate field effect transistor technology and formed on a substrate employing a standard AND-OR structure and two non-overlapping clock phases uses diffused capacitors in a dummy row to model the worst case evaluation time of minterms in the AND plane, and a NOR gate, responsive to the dummy row, for enabling the OR plane to sum the minterms generated by the AND plane.

Abstract: A cover (40, FIG. 1) is provided for installation on an electrical connector to prevent rotation of a coupling nut (24) relative to the body (22) of the connector, which can be readily installed and removed. The cover is in the form of a tube. The tube is constructed of resilient material and has a slot (46) forming a pair of slot edges that can be spread apart to move the cover sidewardly onto or off of the connector. There is a space between the inside of the cover and the connector, with the space (78, FIG. 2) being greater around the nut than around a rearward portion (50) of the body so that compression of the cover causes it to grip the body rather than the nut. The cover has an inwardly-extending ridge-like projection (64) that fits in a recess of the connector between the rear of the nut and the front of an enlarged part of the connector body to limit axial movement of the cover. The ridge is of reduced thickness at locations (80, 82 in FIG.

Abstract: A flushing protection arrangement is provided between the static seal and the auxiliary impeller, so that when the pump is not operating the static seal will be protected by a flushing fluid.

Abstract: A connector system is described, of the type which includes a connector with a pair of contacts and a spring-operated device that shorts the contacts until the connector is mated with another pair of contacts, which is of simple and reliable construction. The spring-operated device includes a largely Z-shaped spring (24, FIG. 2) lying in a slot (30) in a connector housing, with the middle of the spring supported by the slot walls and with opposite ends of the spring resiliently biased against the contacts. The housing is an integrally-molded part with first and second housing parts (50, 52) joined by a hinge, and with the first part having a pair of elongated holes (64, 65) for receiving first and second contacts (16, 18) and with a second housing part having a pair of elongated holes (82, 84) for receiving the mating contacts.

Abstract: An integrated I/O interface for a communication terminal, connectable with an external analog communication device and with an external digital communication device, includes an I/O interface subsystem having analog and digital arrays, a first connector for connecting the I/O interface subsystem to a digital processor for the terminal, and a second connector for connecting the I/O interface subsystem to both the analog communication device and the digital communication device. The digital array and the analog array including a CODEC are mounted on a platform carrier on the I/O interface subsystem board. The second connector is a single connector having pins for transmitting the analog signals, pins for the digital signals, a pin indicating whether the analog or digital mode is selected, and a pin indicating which external communication device is selected. The second connector also has common EMI and EMP protective filter circuits incorporated therein to protect the I/O interface subsystem.

Abstract: A dual-polarization radiating element wherein the phase centers of its constituent radiating elements substantially coincide to provide advantageous operation when the inventive dual-polarization radiating elements are utilized to form wide bandwidth, wide scan-angle, phased array antennas. An inventive dual-polarization radiating element is formed from a substantially planar notch radiating element; a substantially planar dipole radiating element which is interlocked with, and disposed in a plane which is substantially orthogonal to, the notch radiating element; and a structural absorber which is affixed to the notch radiating element and the dipole radiating element.

Abstract: A sheet material for use as a vacuum bag in the vacuum laminating of printed circuit boards, to heat sinks. The material of the sheet is flexible and electrically conductive to both conform around electrical components and to prevent damage to the components due to electrostatic discharge. In addition, the material has one surface which is textured. The sheet material is formed into an enclosure to hold the circuit board and heat sink and it is the textured surface which is placed in contact with the "populated" surface of the board to permit air to be easily removed from the bag enclosure during the initial evacuation stage of the lamination process.

Abstract: A speech coder employs vector quantization of LPC parameters, interpolation, and trellis coding for improved speech coding at low bit rates (400 bps). The speech coder has an LPC analysis module for converting input speech to LPC parameters, an LSP conversion module for converting LPC parameters into line spectrum frequencies (LSP) data, and a vector quantization and interpolation (VQ/I) module for encoding the LSP data into vector indexes for transmission by applying LPC spectral amplitude as weighting coefficients to the LSP data. The VQ/I module outputs one vector index for every two LPC frames in order to reduce the transmission bit rate, and the omitted frames are interpolated on the receiving end. A decoder correspondingly decodes incoming indexes to LPC parameters and synthesizes them into output speech. Trellis coders with an adaptive tracking function encode the pitch and gain parameters of the LPC frames. A universal codebook stores codewords according to a plurality of accents.

Abstract: A color television channel that includes a video channel and at least one sound channel is converted by means of a low-IF converter from the RF band directly to the baseband by analog quadrature conversion. The quadrature output signals are digitized. A correcting stage eliminates the quadrature errors and forms a corrected quadrature pair which drives a video stage and a sound conversion stage. The sound conversion stage includes at least one sound channel converter which converts the low-IF sound channel to its baseband by another (digital) quadrature conversion.

Abstract: A mechanism is described for use with a pair of matable connectors, for locking them together when they have been mated and for later ejecting one from the other, which has the same narrow width as the connectors alone. The mechanism includes a pair of locking/ejecting devices or members (42, 44) pivotally mounted to opposite ends of a first connector (12). The second connector (14) has a shroud (61) with openings (62) near its opposite ends that receive inner parts (72) of the locking members. The inner part of each locking member has a latch (94) that is received in an undercut slot in the shroud, that extends from a shroud opening in the locked position. Each locking member also has an eject part (106) that presses against the base of the second connector as the locking member is pivoted to its eject position, to eject the first connector from the second.

Abstract: Tandem mounted face seals for use in centrifugal pumps with dynamic seals. One face seal has a flexible lip and the other face seal has a non-flexible lip to ensure sealing at high static or dynamic pressures.

Abstract: A tank leak detection system in which a liquid level multiplier is connected to a differential pressure transmitter one side of which may be piped back into the tank to compensate for internal changes in tank pressure. A capillary having a small bore connects the transmitter and the multiplier to reduce temperature effects. Changes in tank temperature may be sensed, i.e., by a long bulb thermometer and either fed to a temperature transmitter to convert temperature change into a single to a computer used to calculate true tank level and output a signal proportional thereto or fed to the level transmitter to compensate for temperature changes.

Abstract: A method of providing a self-aligned gate (SAG) transistor or FET is disclosed. The method permits large aligment tolerances during manufacture of the SAG FET. A reduction in gate resistance is accomplished by including a second layer of gate metallization, which is highly conductive, after the n+ implant and activation anneal without any critical realignment to the first layer of gate metal. The provision of the second layer after the anneal precludes degradation of the conductivity of the second gate metal by interdiffusion with the first (refractory) gate metal during the anneal. The large tolerance for misalignment of the gate mask level is obtained by a planarization of the anneal cap until the top surface of the first layer of gate metal is exposed, all without the need for a separate mask and etch step to open contact "windows" through the planarization anneal cap layers.

Abstract: A central processor for digital signal processing operates at a high clock rate. In the central processor, data is transferred and processed largely in parallel and simultaneously. A buffer is inserted in the data link between a data memory and an ALU by means of at least three data buses so that within one clock period, all necessary data transfers for a two-address operation of the ALU are performed by using the buffer. In particular, a unidirectional data bus and a bidirectional data bus transfer data from the buffer to the ALU, and the bidirectional data bus transfers the result of an ALU operation back to the buffer. Simultaneously with the transfers between the buffer and the ALU, a data transfer is performed between the data memory and the buffer. The data transfers and the data processing are controlled by a control unit in which a fixed program is stored segment by segment. The use of pipelining in the control unit permits a high processing speed.