Abstract: In accordance with the invention, an optical pulse compressor comprises a pulse source, a section of nonlinear optical waveguide including a periodic structure, such as a Bragg grating, for providing positive dispersion and a section of linear optical waveguide including a negative dispersion component. The nonlinear waveguide should have a second order index N.sub.2 at least ten times the second order index N.sub.2 ' of the linear waveguide. The nonlinear waveguide is preferably chalcogenide fiber, with a Bragg grating photoinduced into the core. Because the grating is 4-5 orders of magnitude more dispersive than standard optical fiber, the length of the nonlinear waveguide section can be scaled down to a few centimeters with accompanying reduction of deleterious processes. Modeling suggests that compression factors of 5 with an initial 60 ps pulse are achievable with grating lengths of about 20 cm.

Abstract: A coaxial jack with an internal switch mechanism and a shielded signal conductor includes a cylindrical shell having an axial opening, and an elongate signal conductor supported coaxially inside the shell, and surrounded by a shield that includes an access window positioned so that a portion of the signal conductor is accessible. A back end of an elongate resilient switch contact is fixed by a switch contact support at a back portion of the shell on one side of the shell axis. The switch contact extends inside the shell toward the front opening at a certain inclination and has a free end located on a side of the shell axis opposite the one side. The switch contact is configured and positioned to make an electrical connection with the signal conductor, via the access window in the shield, in the absence of a mating plug. An elongate actuator is supported on the inner periphery of the shell and has an engaging part that protrudes into a defined plug travel path inside the shell.

Abstract: In a digital receiver, an equalizing unit includes a power controller adapted to scale received components of a quadrature amplitude modulated signal based on a constellation size of the quadrature amplitude modulated signal. Alternatively, a method of scaling components of a quadrature amplitude modulated signal includes the steps of searching the quadrature amplitude modulated signal to determine a constellation size, and scaling the components of the quadrature amplitude modulated signal based on the constellation size.

Abstract: A variety of FIFOs, including single and dual port, RAM-type and/or having a ring-type addressing mechanism, are tested by causing the FIFOs to execute a test method comprised of a series of steps. Upon execution, the steps cause the FIFO to manifest a variety of faults. This test method manifests faults by monitoring the outcome of operations and the values of particular flags indicative of normal FIFO operation.

Abstract: The present invention is directed to methods of creating a cavity to contain an interconnect leading to a location within a substrate. The substrate has a first dielectric layer of a first etch rate over the location, and a semiconductor device containing the interconnect. One of the methods includes the steps of: forming a second dielectric layer on the first dielectric layer wherein the second dielectric layer has a second etch rate that is slower than the first etch rate, forming a photoresist layer on the second dielectric layer and etching into the first and second dielectric layers to form the cavity leading to the location. The second dielectric layer acts as a profile guiding layer to form a plug and runner simultaneously in a single etching step while controlling relative size of the plug and runner.

Abstract: A method of testing field programmable gate arrays (FPGAs) includes establishing a first group of programmable logic blocks as test pattern generators or output response analyzers and a second group of programmable logic blocks as blocks under test. This is followed by generating test patterns and comparing outputs of two blocks under test with one output response analyzer. Next is the combining of results of a plurality of output response analyzers utilizing an iterative comparator in order to produce a pass/fail indication. The method also includes the step of reconfiguring each block under test so that each block under test is tested in all possible modes of operation. Further, there follows the step of reversing programming of the groups of programmable logic blocks so that each programmable logic block is configured at least once as a block under test.

Abstract: Outdoor, electronic component containing cabinets are cooled by forced circulation of outside air through the cabinet for direct, cooling contact with the components. The incoming air is filtered, heated as necessary to evaporate water droplets in the air prior to entry of the air into the component containing portions of the cabinet, and the air flow is regulated for slowing the flow rate of the air within the cabinet as is necessary for maintaining the relative humidity within the cabinet below a maximum percentage; typically 40%.

Abstract: For use with a valve regulated lead acid (VRLA) battery, a fluid fill system and a method of maintaining fill fluid in a VRLA battery. In one embodiment, the system includes: (1) a fluid determination circuit, associated with the battery, that determines a quantity of fill fluid in the VRLA battery and (2) a controller, coupled to the fluid determination circuit, that introduces replacement fill fluid into the VRLA battery based on the quantity to replace fill fluid lost from the VRLA battery. The fluid determination circuit comprises sensors that measure a temperature and pressure associated with the VRLA battery, and a state of a fluid release valve on the battery.

Abstract: A process for fabricating thin film transistors in which the active layer is an organic semiconducting material with a carrier mobility greater than 10.sup.-3 cm.sup.2 /Vs and a conductivity less than about 10.sup.-6 S/cm at 20.degree. C. is disclosed. The organic semiconducting material is a regioregular (3-alkylthiophene) polymer. The organic semiconducting films are formed by applying a solution of the regioregular polymer and a solvent over the substrate. The poly (3-alkylthiophene) films have a preferred orientation in which the thiophene chains has a planar stacking so the polymer backbone is generally parallel to the substrate surface.

Abstract: A temperature-compensated tunable optical waveguide grating device comprises a length of optical waveguide grating including an optical grating region, a guiding tube or frame mechanically coupled to the waveguide at one end of the grating region, and mechanically coupled to the waveguide at the other end of the grating region, a movable element responsive to control signals for applying adjustable strain across the grating region, thereby tuning the grating. The device further comprises a temperature-compensating element for modulating the strain in proportion to changes in temperature, thereby temperature compensating the device. Advantageously the waveguide is an optical fiber and the movable element is a movable magnet.The inventive device can reduce the temperature-dependent wavelength change to less than 0.5 nm/100 deg. C., and advantageously less than 0.05 nm/100 deg. C.

Abstract: An integrated circuit includes a memory cell that stores a data bit corresponding to one of a low and a high voltage. A memory element is coupled to a data node for storing the data bit and to an inverse data node for storing an inverse of the data bit. An access port of the memory cell comprises an access switch having a first terminal coupled to a data line, a second terminal coupled to the data node, and a control terminal coupled to an access control line which provides an access control signal for switching the access switch on or off to selectively couple the data line to the data node. The memory cell has a preset switch having a first terminal coupled to the inverse data node, a second terminal coupled to a logic-0 voltage source, and a preset control terminal coupled to a preset control line which provides a write preset control signal for switching the preset switch on or off to selectively couple the inverse data node to the logic-0 voltage source.

Abstract: An adjustable modular panel for partially housing data carrying cables and facilitating connection between the cables and communication equipment. The modular panel includes first and second panel portions, each having an engaging edge for mating with each other and for forming between the first and second portions a trough having an area in which the cables are at least partially housed. A fastening device in the panel portions is releasably operable to secure the two panel portions together. Each panel further includes a mounting surface to which connection devices are mountable. In a preferred embodiment, a third panel having a pair of engaging edges is disposed between the first and second panel portions so that the engaging edges of the third panel mate with the engaging edges of the first and second panel portions, thereby expanding the trough area to accommodate an increased number of cables and/or cables having increased dimensions.

Abstract: Battery backed-up power units, and battery disconnect modules and methods of manufacturing the same. One of the battery disconnect modules includes: (1) a contactor having a body, a control input and rigid conductors extending from the body and (2) a control circuit mount, connected to and supported by the rigid conductors, that contains control circuitry that controls the contactor by the control input, the rigid conductors connected to busbars within the battery backed-up power unit to provide a mount for the battery disconnect module and allow said control circuit to monitor a characteristic of a battery within the battery backed-up power unit and control the contactor in response thereto.

Abstract: Embodiments of the invention include an amplifier such as a differential amplifier having an improved common mode voltage range (CMVR). The amplifier includes a translator coupled to a second stage amplifying circuitry wherein the translator uses feedback and a parallel connection of input devices to improve the common mode voltage range of the amplifier while providing for enablement of the circuit functionality. The translator uses parallel connections of N-channel and P-channel devices such as transistors to extract alternating current (ac) signals riding on a common mode voltage and to translate the extracted ac signals to ride on a constant reference voltage (V.sub.ref). The translated signals are then amplified in a conventional manner, such as by a gate thresholding or a self-biasing technique. An input sensing circuit within the translator provides an offset detection signal to a correction circuit, also within the translator.

Abstract: One-by-three and two-by-two optical switches comprising optical waveguides or fibers with tapered ends that utilize electrostatically-driven actuators are disclosed. Tapering of the fiber ends allow the ends to be positioned in close proximity to one another to yield an optical switch with low insertion loss.

Abstract: A modem having an interactive clearing circuit that provides the facility for the modem to mix interleaved and non-interleaved writes to a FIFO without timing problems or data transfer problems associated with the prior art. The circuit includes a self-clearing error bit circuit that clears the error bits of an interleaved write from the LSR after each FIFO write. In one embodiment, the clearing circuit provides dummy bits to the LSR upon each controller write to the FIFO. This prevents error bits associated with previous interleaved writes from becoming associated with subsequent non-interleaved writes.

Abstract: An improved TCP/IP protocol for use in a client/server network is disclosed. The improved protocol allows a server to switch execution of an application from one processor or task to another processor or task without interruption of the IP connection or serious delay in execution of the application by a server or client. As implemented, each server usually includes a unique hardware address, an improved IP layer with a shared IP address, a "Speak No Evil-Communication Protocol" layer with a unique SNE-CP address, a soft switch protocol ("SSP") layer with at least one unique SSP address assigned to a process or task, usually a TCP layer, at least one SSP monitoring process and a processor executing at least one software application. In this invention, each server typically receives each message packet from each client; however, only one server is allowed to respond to the client's message.

Abstract: Compliant, resilient mounting means are provided for minimizing stress on the platform of an optical sub-assembly package caused by temperature change and the like so as to maintain good alignment between the laser beam emitted from a laser chip mounted on the platform and the lens of an optical fiber also mounted on the platform. The resilient means comprise resilient solder bumps of the order of 625 microns thick interposed between the platform and the base to provide a resilient connection between the platform and the base, thereby maintaining good alignment between the laser beam and the lens by reducing the stresses on the optical sub-assembly platform that tend to be caused by temperature changes or the mounting of the package to a rigid, external platform, as by bolting.

Abstract: A large optical preform 303 is made by a modified chemical vapor deposition (MCVD) process by depositing successive layers of core and cladding materials onto the inside surface of a rotating glass tube 33 having a hydroxyl ion (OH.sup.-) level that is less than 0.5 parts per million (ppm) by weight. The tube is then collapsed inwardly to form a core rod 301 in which the deposited core material 31 has a diameter that is greater than about 5 millimeters and the deposited cladding material 32 has an outside diameter that is less than about 15 millimeters. A machine-vision system 140, 150, 160 monitors and controls the diameter of the glass tube by regulating the pressure within the tube. Moreover, the machine-vision system monitors and controls the straightness of the tube by varying its rotational speed according to angular position. After the core rod 301 is formed, it is plasma etched to remove contaminants, and then overclad with two glass jackets 34, 35 having a hydroxyl ion (OH.sup.

Abstract: A system and method to measure channel quality in terms of signal to noise ratio for the transmission of coded signals over fading channels. A Viterbi decoder metric for the Maximum Likelihood path is used as a channel quality measure. This Euclidean distance metric is filtered in order to smooth out short term variations. The filtered or averaged metric is a reliable channel quality measure which remains consistent across different coded modulation schemes and at different mobile speeds. The filtered metric is mapped to the signal to noise ratio per symbol using a threshold based scheme. Use of this implicit signal to noise ratio estimate is used for the mobile assisted handoff and data rate adaptation in the transmitter.