Abstract: In a tunable recursive filter implemented in a microwave monolithic integrated circuit (MMIC), a second-order recursive filter included two first order filters, having first and second transmission lines, respectively, connected in parallel. An amplifying unit having a cascode amplifier is arranged in a forward path shared by the two first-order filters. A combiner receives an input signal and a first and second feedback signals fed back through the first and second transmission lines, respectively, and combines such signals to output a combined signal. The amplifying unit amplifies the combined signal and outputs an amplified signal. A divider divides the amplified signal from the amplifying unit, outputs a first portion of the divided signal, and feeds back a second and third portion of the divided signal through the first and second transmission lines.

Abstract: A bus interface system and method includes a driver circuit and a receiver circuit coupled on opposite ends of a conducting line of a bus. The driver circuit drives an adjustable current through the conducting line to the receiver circuit. The current level of the adjustable current can be adjusted to one of several levels according to the data item being transferred across the line. The receiver circuit receives the adjustable current and detects the level of the current to identify the information encoded by the signal being transferred. The current level can be set to one of several values such that the information being transferred by the signal can be in one of several possible states. The system therefore is capable of encoding more data than binary systems. Higher data bus transfer rates can therefore be realized.

Abstract: Devices are disclosed for performing transmyocardial revascularization (TMR), percutaneous revascularization and other thermal tissue therapies. The invention utilizes a coring needle with an associated heating element to core out tissue to form a channel in the myocardium, and concurrently thermalize a thin tissue layer at the wall of the channel. The invention yields myocardial channels similar to those obtained with conventional techniques, but with lower energy requirements. The invention further new closure mechanisms for transmyocardial applications.

Abstract: An improved clasp assembly which can be readily detached and reconnected to one or more strand ends, the latter being configured to be passed through jewelry components being slidably mounted on the strands. One embodiment of the clasp assembly comprises a catch permanently secured to one strand end, and a housing detachably secured to the other strand end. The catch is separably received in snap engagement within the housing, and the housing includes a latch mechanism accommodating its detachment and reattachment to the other strand end without the need to employ specialized tools or to involve jewelers.

Abstract: A charge pump circuit including current source circuits for maintaining the current sourced from an upper current source substantially equal to the current sunk by a lower current source. The current source circuits include a lower reference current source operable for defining a reference current through a first biasing transistor and a duplicate device in which an output current can be established proportional to the reference current therethrough. A complementary output device is provided for producing the upper current source along with a duplicate biasing device. The duplicate complementary biasing devices are such that the current through these devices is identical and equal to the reference current. A replication feedback loop coupled to both the common connected node of the complementary output devices and the common connected node of the complementary biasing devices operates to make the voltage at these two nodes substantially identical.

Abstract: A semiconductor structure including a semiconductor substrate, at least one first crystalline epitaxial layer on the substrate, the first layer having a surface which is planarized, and at least one second crystalline epitaxial layer oil the at least one first layer. In another embodiment of the invention there is provided a semiconductor structure including a silicon substrate, and a GeSi graded region grown on the silicon substrate, compressive strain being incorporated in the graded region to offset the tensile strain that is incorporated during thermal processing. In yet another embodiment of the invention there is provided a semiconductor structure including a semiconductor substrate, a first layer having a graded region grown on the substrate, compressive strain being incorporated in the graded region to offset the tensile strain that is incorporated during thermal processing, the first layer having a surface which is planarized, and a second layer provided on the first layer.

Abstract: A pre-amp circuit including a photodiode, first and second amplifiers and a differential amplifier reduces or eliminates noise in an input signal. The photodiode converts an external optical signal into an electrical signal which includes noise. The first amplifier amplifies the difference between an output voltage of the photodiode, including the noise, and the reference voltage, to generate a difference signal which includes a first noise component. The second amplifier buffers the reference voltage to generate a signal which includes a second noise component which is in-phase with the first noise component. The differential amplifier amplifies the difference between the voltages output from the first and second amplifiers to generate an output signal which is substantially devoid of such noise. The present invention is amenable to application in remote control receiver systems.

Abstract: A highly efficient channel drop filter. The filter employs a coupling element including a resonator-system between two waveguides, which contains at least two resonant modes. The resonator-system includes one or more interacting resonant cavities which in addition to being coupled to the waveguides, can also be coupled directly among themselves and indirectly among themselves via the waveguides. Each component of the coupling element can be configured or adjusted individually. The geometry and/or dielectric constant/refractive index of the resonator-system are configured so that the frequencies and decay rates of the resonant modes are made to be substantially the same. The filter can achieve 100% signal transfer between the waveguides at certain frequencies, while completely prohibiting signal transfer at other frequencies. In exemplary embodiments, the filter is configured with photonic crystals.

Abstract: A differential delay circuit type ring oscillator allows for an increase in operation enabling frequency and dynamic range. At each stage of the ring, delay circuit output signals arc linearly varied above and below the circuit switching level. The ring oscillator includes a plurality of differential delay circuits coupled in series in a ring configuration, a differential amplifier, and a comparator. Each of the differential delay circuits receives first and second differential input signals, and delays the received signals by a predetermined time in response to a predetermined control signal to generate first and second differential output signals. The differential amplifier receives the first and the second differential output signals of one of the differential delay circuits and amplifies the received signals to generate first and second differential amplified signals.

Abstract: A device for triggering the inspiratory phase of a ventilator having a three-way connector with an inspiratory conduit and an expiratory conduit, each communicating with the ventilator and with a patient communicating conduit. A valve arrangement associated with both the expiratory and inspiratory conduits are automatically operated by a patient attempting to breathe, such that the patient is only exposed to the air volume in the three-way connector and not to the greater air volume of the ventilator and its connected tubing.

Abstract: The invention relates generally to transport systems for cutting articles from a blank of material, and is well suited for use in, though not limited to, transporting and cutting labels from a web material and applying them to items. Specifically, an article transfer system is disclosed for transporting articles cut from a blank of material traveling in a first direction. The system comprises a support member including first and second surfaces and a plurality of openings extending between the first and second surfaces. The support member is movable along the first direction adjacent to the blank of material. The system also includes in one embodiment, a vacuum for generating a lower pressure adjacent to the second surface of the support member than the pressure adjacent to the first surface thereof such that the blank is urged to maintain contact with the first surface of the support member.

Abstract: An endoluminal device slippage sensor system including an electrically conductive endoluminal device and a catheter assembly to which the device is coupled for deployment into a lumen. First, second and third electrodes are associated with the catheter assembly, each respectively in direct electrical contact with a proximal, a middle and a distal portion of the device. A potential source generates a potential between the first and second electrodes and between the second and third electrodes. The potential between the electrodes is varied in accordance with a change of position of the device along the axis of the catheter assembly during deployment in which the proximal or distal portion of the device is disconnected from the first or third electrode, respectively.

Abstract: A system for and method of controlling the temperature of a flat workpiece such as a semiconductor wafer are disclosed. The workpiece is mounted on a workpiece chuck which is mounted over a base between the chuck and a host machine such as a wafer prober used to test integrated circuits on a wafer. The chuck includes an upper portion on which the workpiece is mounted. The temperature of the upper portion of the chuck is controlled to control the temperature of the workpiece. The temperature of the base is controlled to reduce the amount of heat flow between the chuck and the host machine. A power and control system includes a switching power supply which provides power to system components including heaters in the chuck used to heat the workpiece. A series of filters removes electrical noise generated by the switching power supply such that low-noise operation is realized.

Abstract: A synchronous burst semiconductor memory device operating in synchronism with at least one external clock signal and capable of accessing data on every edge of the external clock signal is provided. The burst memory device includes a clock generator for generating a number of data output/input strobe clock signals synchronized with the external clock signal in response to a plurality of input information signals, and a data-out/in buffer for outputting/inputting internal/external data in synchronism with the data output/input strobe clock signals.

Abstract: A method and system which combines a properly designed FEC and the periodic transmission of known symbols to obtain a desired error performance in a point-to-multipoint digital transmission system employing a DFE which induces error propagation. A transmitter unit includes a forward error correction encoder (FEC) which implements a code to information provided to an input of a data interleaver having block length N and interleaving depth D, and a data modulator which is coupled to an output of the data interleaver to receive a stream of data symbols. At least one receiver unit includes a decision feedback equalizer (DFE) which includes a feedback filter and provides an input to a data deinterleaver having block length N and interleaving depth D, and a FEC decoder which receives data from an output of the data deinterleaver. Sequences of known symbols of length at least equal to the length of the feedback filter are periodically added to the output of the data interleaver.

Abstract: An isolator having a driver circuit which is responsive to an input signal to drive signals into a magnetic-field generator such as at least one coil. The generator is magnetically coupled to a sensor that includes spin-valve resistors which have resistance characteristics that are variable in response to the magnetic field generated by the generator. A receiver circuit incorporating a strobe generator converts the resistance changes to an output signal corresponding to the input signal.

Abstract: Alignment marks on first and second plates include a plurality of periodic gratings. A grating on a first plate has a period or pitch p.sub.1 paired up with a grating on the second plate that has a slightly different period p.sub.2. A grating on the first plate having a period p.sub.3 is paired up with a grating on the second plate having a slightly different period p.sub.4. Illuminating the gratings produces a first interference pattern characterized by a first interference phase where beams diffracted from the first and second gratings overlap and a second interference pattern characterized by a second interference phase where beams diffracted from the third and fourth gratings overlap. The plates are moved until the difference between the first and second interference phases correspond to a predetermined interference phase difference. Further invention uses an interrupted-grating pattern on the second plate with certain advantages.

Abstract: A structure and method for mounting a processor assembly on a mother board and a structure and method for cooling the processor assembly are described. The processor assembly includes a processor circuit board assembly which is located adjacent to a heat sink for removing heat from the circuit board assembly. The heat sink and circuit board assembly are maintained in an upright position with respect to the mother board by a frame mounted on the mother board and/or the computer system chassis. A cover mounted to the top of the frame holds a connector on the processor circuit board assembly in mating contact with a connector on the mother board. The cover also serves to complete an enclosure around the heat sink and processor circuit board assembly. Fans mounted to the frame move air from an intake end of the processor assembly, across cooling fins on the heat sink, to an outlet end of the processor assembly such that a ducted cooling system is provided for the processor assembly.

Abstract: A backplane stiffener mounts in a channel defined between parallel rows of connectors on a backplane. In a first embodiment, the stiffener has a substantially U-shaped cross section and has a maximum width less than the width of the channel. The sidewalls are parallel and linear throughout the length of the stiffener. A second embodiment is adapted for use in "dog-legged" connector channels wherein at least one of the connectors in the row is wider than or spatially offset from the remaining connectors. The stiffener is preferably formed from a sheet of pliable material, for example sheet metal which is manipulated to form various features and folded longitudinally to form a rigid member. Rigidity is enhanced in an economic manner which does not interfere with backplane operations.