Abstract: In a novel tunable semiconductor laser, the lasing transition is a non-resonant tunneling transition, with the frequency of the emitted photon depending on the electrical bias across the multi-period active region of the laser. The laser can be designed to emit in the mid-IR, and can advantageously be used for, e.g., trace gas sensing.

Abstract: Telecommunications processing is applied to a reference signal to generate a signal under test. A fidelity measure is generated characterizing the fidelity of the signal under test relative to the reference signal. A control signal is generated from the fidelity measure, where the control signal is used as a feedback signal to adjust the telecommunications processing. In one embodiment, the reference signal is a speech signal and the signal under test is a decoded speech signal generated by encoding, transmitting, and decoding the reference speech signal. The fidelity signal is an average mean opinion score (MOS) and the control signal is used to control the speech decoding processing. For example, the speech decoding processing may involve a speech decoder followed by a post filter, and the control signal is the cut-off frequency of the post filter.

Abstract: Each of a plurality of photodiodes forming a photodetector is mounted on a respective metal pad on the surface of a semiconductor integrated circuit chip including a corresponding number of amplifier circuits for detecting the photocurrent from respective photodiodes. Each circuit comprises a high gain, high input impedance amplifier and a feedback element, typically a resistor of high value, connected across the amplifier between input and output nodes thereof. Each photodiode mounting metal pad and each feedback resistor is connected to a common input node of a respective amplifier by metal paths within a connecting structure forming part of the integrated circuit. Adverse effects on the output current from the photodiodes are reduced by forming a junction of the path from each feedback resistor with the path from the corresponding photodiode at the metal pad on which the photodiode is mounted, and interconnecting such junction along a common path to the corresponding amplifier input node.

Abstract: The present invention provides methods and apparatus for analyzing the particulate contents of a sample such that a high proportion of the sample particles are analyzed without discrimination against high electronegativity and high ionization potential elements. In an exemplary embodiment, the invention comprises an apparatus for analyzing the particulate content of a sample having particulate diameters in the range of 0.001-10 microns. The apparatus comprises an evacuable chamber equipped with a chamber entrance through which a particle-laden gas stream enters. An inlet device, such as a capillary, communicates with the chamber entrance for inputting the particle-laden gas stream to the evacuable chamber. A laser is positioned to produce a focused laser beam which intersect the particle-laden gas stream at position approximately 0.1 mm from the chamber entrance. The laser beam has a power density sufficient to fragment and ionize particles entrained within the particle-laden gas stream.

Abstract: The apparatus has a substantially planar base having a surface which defines a wafer cassette receiving station and a wafer receiving station. A transportable wafer cassette is removably coupled to the base in the wafer cassette receiving station. The transportable wafer cassette is provided for holding a plurality of wafers in an axially aligned manner, each of the wafers having identification indicia disposed on a surface thereof. A wafer receiving cassette is coupled to the base adjacent to the transportable wafer cassette in the wafer receiving station. A first reciprocally moveable wafer transfer member is attached to the base, and is operative for transferring the wafers held in the transportable wafer cassette to the wafer receiving cassette.

Abstract: An integrated circuit includes a string of substantially similarly-shaped resistive cells, each cell having a first resistive portion and a second resistive portion, the string having an overall orientation and at least one cell, preferably substantially all cells, and more preferably all cells have their respective centerlines oriented at non-orthogonal angles, preferably about 45 degrees, relative to the overall orientation. The cells are contiguous such that a resistor is formed by the first resistive portion of one cell and the second resistive portion of an adjacent cell. The cells preferably have a substantially hexagonal shape and are arranged into substrings. If the string includes a folding point, substrings immediately adjacent to the folding point should include an odd number, preferably three, of cells, and substrings not adjacent to the folding point should comprise an even number, preferably two, of cells.

Abstract: The traffic shaping system according to the principles of the present invention increases the connection-carrying capacity of a network node by shaping the data cells to increase the admissible number of connections. In accordance with certain embodiments of the present invention, the traffic shaping system uses a data buffer at the ingress of the network node to selectively buffer classes of data cells. As such, the traffic shaping system exploits differences in delay tolerances between traffic classes to shape the less delay sensitive traffic classes to reduce the effective bandwidth of a connection of the particular traffic class and thereby increase the nodal connection-carrying capacity. Certain embodiments of the traffic shaping system operate within a framework to provide parameters for the traffic shaping system which increase the connection-carrying capacity for the node while meeting quality of service requirements for the data cells.

Abstract: A hypothetical query in a database system is transformed using algebraic equivalences involving explicit substitutions so as to produce one or more equivalent queries which can be evaluated more efficiently than the original hypothetical query. The hypothetical query may be of the form Q when {U} where Q is a relational algebra query and U is an update expression. The value assigned to the hypothetical query in a database state DB is the value that Q would return in the database state reached from DB by executing update U. One or more explicit substitutions are used to represent hypothetical database state changes, and algebraic equivalences involving the explicit substitutions are applied to the hypothetical query in order to generate at least one additional query which is equivalent to the hypothetical query. Several equivalent queries may be generated, and their estimated computation times compared, in order to select a particular equivalent query for direct evaluation.

Abstract: A dielectric layer consisting essentially of Ta, Al, oxygen and nitrogen can have advantageous properties that make such a layer useful for thin film capacitors, typically capacitors for Si integrated circuits. For instance, a significantly greater fraction of capacitors according to the invention than of prior art tantalum oxide capacitors can store a charge of 3 .mu.coulomb/cm.sup.2. In a currently preferred embodiment, the dielectric layer has composition Ta.sub.1-y Al.sub.y O.sub.x N.sub.z, with y.about.0.1, x.about.2.4, and z.about.0.02. The dielectric layer can be formed by sputter deposition or any other appropriate deposition technique, e.g., chemical vapor deposition.

Abstract: In an arrangement substantially like an optical isolator, appropriate choice of the composition of the magneto-optic element can result in a variable optical attenuator. The composition is selected to vary in the direction of light propagation, and also is selected such that the magneto-optic element comprises a compensation wall. The compensation wall is movable in response to a change in the temperature of the magneto-optic element, whereby the attenuation of the device is changed.

Abstract: A linkage couples the coin return door of a coin telephone instrument to a cam mounted in the coin return chute. When the coin return door is opened in the normal manner by a customer to retrieve coins from the coin return hopper, the cam closes a contact of a microswitch that completes a circuit. After a normal coin retrieval the door closes and the switch contact returns to open. Such momentary switch closures are considered normal. However, if foreign matter has been stuffed into the coin return hopper by a fraudulent user, the material will be engaged by a comb at the end of the cam, preventing the coin return door from closing normally. When the door is prevented from closing normally and remains open for more than a few moments, the switch remains actuated, keeping the circuit closed for longer than normal thereby signaling the signaling the telephone company that the phone has been tampered with.

Abstract: This invention relates to a token passing network, called a Universal BIST Scheduler (UBS), and a method for scheduling BISTed memory elements based on: executing BIST in multiple stages in order to optimize the efficiency of continuous processing and to apply a single waiting period to multiple SBRIC.sub.-- RSs where, for example, BIST includes retention testing; dividing resource controllers or SBRIC.sub.-- RSs corresponding to one or more RSB elements into a matrix such that each SBRIC.sub.-- RS executes the BIST of its memory elements concurrently and/or successively depending on the SBRIC.sub.-- RS's position in the matrix; and passing a token to initiate processing of a set of SBRIC.sub.-- RSs in the matrix through a level signal rather than a pulse signal in order to ensure that the signal is not lost.

Abstract: A method for forming a dielectric oxide layer on selected areas of a substrate is disclosed. The dielectric oxide layer is formed on selected areas of the substrate using a sol process. The substrate has an area of a first material and an area of a second material which is different from the first. The first material is coated with a layer of a first compound. The layer of the first compound has a hydrophobic top surface. The second material is coated with a layer of a second compound. The layer of the second compound has a hydrophilic top surface. A layer of hydrous oxide is formed over the second compound by applying an aqueous sol solution on the surface of the substrate. The substrate is then heated to remove the first compound and the second compound from the surface of the substrate. Thereafter, the substrate with the layer of hydrous oxide thereon, is sintered to form the dielectric oxide layer.

Abstract: A low noise transistor IC or module comprises a plurality of conventional CMOS transistors which are laid out in parallel in such a way that the effective gate width of the combination of transistors is increased, yet the effective gate resistance and hence the noise figure (NF) of the circuit are reduced. A low noise amplifier incorporating such a module is also described.

Abstract: Automatic testing a group of line circuits on a smart line card served by a central switch over a PCM bus is localized by using the microprocessor/DSP that provides codec functions for the group of line circuits. Tests such as DC overhead that are not performable by the central switch over the PCM bus are performed by the microprocessor/DSP when informed by the central switch that at least one of the channels is not processing voice signals. The microprocessor/DSP controls test switches on the line card to set-up various test terminations for the idle circuit as well as to selectively control the gain of the idle channel's amplifiers. The microprocessor/DSP synthesizes test tones and executes test tone detection processes within the time slot intervals accorded by the central switch to the idle channel.

Abstract: A fixture for use in the bonding of a plurality of chips each to a respective one of a plurality of substrates includes a lower vacuum chuck and a frame member supported on the chuck for reciprocatory motion toward and away from the chuck surface. The chuck surface is arranged to hold substrates with predeposited solder in pockets at predetermined locations thereon. The frame member has openings aligned with those pockets and weights which extend through the openings. After substrates are placed on the chuck surface, the substrates are heated so that the predeposited solder reaches eutectic status, and then chips are placed on the substrates. The frame member is then mounted on the chuck and gradually lowered until the weights press against respective chips, thereby holding the chips in position on the substrates. The entire assembly is then transported to a solder reflow bonding station.

Abstract: The specification describes a composite TiN barrier layer structure formed by depositing a first TiN layer by CVD to obtain good step coverage, followed by a second TiN layer formed by PVD to obtain uniform surface morphology for subsequent deposition of an aluminum alloy contact layer. Alternatively, uniform TiN layer morphology is obtained by depositing multiple CVD TiN layers as a series of thin strata, and passivating after each deposition step to fully crystallize each stratum thereby obtaining a uniformly crystallized barrier layer.

Abstract: A wavelength-selective add-drop multiplexer is disclosed for adding and/or dropping spectral components from a wavelength-division-multiplexed optical signal. (1.times.1) or (2.times.2) optical switches are used, either alone or in conjunction with other optical elements, to separate spectral components identified for drop from other spectral components.

Abstract: A multi-beam antenna for a wireless communication network, a method of creating cells for a wireless communication network with a multi-beam antenna held aloft by an aeronautical vehicle and a wireless infrastructure. The multi-beam antenna projects: (1) a first antenna beam to create a first cell upon a generally circular first terrestrial area below the multi-beam antenna and (2) a second antenna beam to create a second cell upon a generally circular second terrestrial area below the multi-beam antenna, the first cell having a smaller radius than, and substantially concentric with, the second cell.

Abstract: A system and method for caching frequently called numbers so that call delivery time is shortened and the signaling network and service nodes are not overloaded by telephone number queries. In a distributed control switching system, each processor that performs digit analysis and has an area of memory. This area of memory is used as a cache to store directory number translation information. When a call arrives for a specified directory number (DN), if, after standard translation, the call cannot be normally routed, then the cache is consulted to determine whether the destination for that DN is in the cache. If it is, then the call is routed to the destination associated with the DN. If, however, the DN is not in the local cache, then a query is sent to one or more other units in the switch which may contain such caches in order to determine if these caches contain the destination.