Abstract: For use in a power converter having a power switch and a synchronous rectifier device coupled between an input and an output thereof, a transient response network, method of disabling a synchronous rectifier device and power converter employing the network and method. In one embodiment, the transient response network includes a synchronous rectifier controller, coupled to the power switch and the synchronous rectifier device, that senses a state of the power switch and disables the synchronous rectifier device when the power switch has remained in a nonconducting state for at least a specified period of time.

Abstract: A system for positioning an article at a predetermined angular orientation with respect to a vacuum collet comprising a vacuum collet having an article pickup surface; and an alignment ledge overhanging the pickup surface, wherein the alignment ledge is at a predetermined angular orientation with respect to the vacuum collet.

Abstract: A Time Division Multiple Access (TDMA) duplex radio communication system uses an Interrogator to generate a first radio signal by modulating a first information signal onto a radio carrier signal which is sent to at least one remote Tag of the system. The remote Tag receives and modulates a second information signal onto a second radio carrier signal to form a second modulated signal which is transmitted, in a time-slotted manner, back to the Interrogator. The remote Tag selects, or is instructed, how many times it should repetitively transmit the second modulated signal; and selects, or is instructed, over how many of the time slots following receipt of the first radio signal the remote Tag should repetitively transmit the second modulated signal. Other embodiments use Modulated Backscatter to transmit the second modulated signal, and use homodyne detection to demodulate the second modulated signal.

Abstract: PCS switching system processes the movement of a wireless set from one paging zone to another paging zone or from one base station to another base station at the lowest software layer in the PCS switching system thereby reducing the amount of processing required of the PCS switching system. Each base station is interconnected to the wireless switching network by communication links. When a wireless set registers on the wireless switching network via a base station, a physical object is established that will control the physical protocol used to communicate with the wireless set. In addition, a software object is established that will control the first layer of software protocol to communicate with the wireless set. When the wireless set moves to a new base station that interconnects to the wireless switching network, it initiates contact with the new base. This initialization causes a new physical object to be established.

Abstract: A field-effect photo-transistor, being a three-terminal photosensing electrical device, based on integrated metal oxide semiconductor (MOS) technology. The device features a high output impedance which makes it particularly suitable as a photosensor for active pixel imaging arrays. Unlike the bipolar photo-transistor, which is a device well known in the art, the field-effect phototransistor is more compatible with MOS VLSI (Very Large Scale Integration) technology by inherently being a unipolar type device. Active pixel imaging arrays based on the disclosed invention can be integrated on the same semiconductor substrate with conventional digital or mixed signal processing functions to produce single-chip image processors for video or still picture cameras.

Abstract: A system and method for reliable transmission of information using asynchronous transfer mode (ATM) through a noisy transmission path such as a wireless or satellite transmission link. To efficiently adapt ATM to such wireless links requires the ability to discern ATM cell addresses in a high noise environment. The system and method provides multiple redundant addressing to reduce or eliminate misrouting of ATM cells transferred through such a noisy transmission link. The multiple redundancy addressing realizes multiple virtual circuits to the same destination. The multiple redundant addresses for the circuits are within the error space of a principal address used for actual transmission. Thus, the most probable error patterns occurring in the ATM address field will change the principal address to a redundant address to the same destination, thus avoiding misrouting of the ATM cell.

Abstract: A time-domain signal processing system for displaying, classifying, and recognizing temporal and spectral features in terahertz waveforms returned form materials. Specifically, novel techniques are described for classifying and analyzing the free induction decay exhibited by gases excited by far-infrared (terahertz) pulses. Illustratively, a simple geometric picture may be used for the classification of the waveforms measured for unknown gas species and gas mixtures.

Abstract: A method and apparatus for secure entry and authentication of a multi-digit personal identification number (PIN) is described. An authenticator generates a random number, and provides that number, or a function thereof, to a user. The user is prompted to encode each digit of the PIN number, one digit at a time, by performing a mathematical operation on the digit using the number provided by the authenticator. The encoded PIN digit is provided to the authenticator which reverses the steps performed by the user to regenerate and verify the user's PIN. The user is prompted to encode subsequent digits of the PIN only after (1) a previous digit is encoded, (2) the encoded digit is provided to an input device for the authenticator, (3) and a new random number is generated and that random number, or a function thereeof, is provided to the user for encoding a subsequent PIN digit.

Abstract: An apparatus and method performs a carrier signal acquisition operation in a receiver of a wireless portable unit. In order to locate and lock onto a carrier signal, a processor in the receiver is configured to sequentially examine each of a plurality of designated frequency bands within a predetermined frequency range, starting with the frequency band having the highest probability of containing the carrier signal. Through this acquisition operation, the carrier signal is easily located when outside of the normal search range of the processor. Since frequency errors due to, for example, the effects of variation and aging of hardware circuits are easily corrected, an inexpensive temperature compensated crystal oscillator may be employed in the receiver of the portable unit.

Abstract: In a cellular telephone terminal having increased storage capability, ease of entry and access for data stored therein is provided through utilization of a computer equipped with a modem, a wired telephone network and the cellular telephone network. A user utilizes the ease of data entry implicit to modern computers through dedicated or existing personal information organizers to input data into a database, such as a personal dialing directory, at the computer. For the entering of data at the cellular telephone terminal, first the terminal, also equipped with a modem, is configured in a data download mode where data can be received from the computer and entered into on-board storage. The computer then places a modem telephone call to the terminal, either directly or through a network translator, and transfers the data into the terminal. The data is then accessible through standard data recall techniques using a display and interface keys on the telephone terminal.

Abstract: An improved method of coating an optical fiber is disclosed. A transducer is submerged in a container of liquid coating material and activated so that it causes the formation of a wave of coating material within the container. The optical fiber is then drawn through the container and through the wave, the wave counterbalancing the negative meniscus produced by drawing the fiber through the container. A curved housing also may be placed in the container and surrounding the transducer for controlling the size, amplitude, shape, or direction of the wave. A plurality of transducers also advantageously may be used.

Abstract: The fusible element of an electrical fuse is made from carbon glass. The carbon glass melts and pulls apart safely when the fuse blows, so the fusible element normally does not need an enclosure. The carbon glass glows and emits light when current flowing therethrough approaches the fuse's current-carrying capacity, thereby acting as a current sensor and a warning indicator that the fuse is about to blow.

Abstract: A method for making a fused fiber bundle by providing a bundle of optical fibers, heating the fibers by a flame extending axially along the bundle, and translating the flame axially along the fibers. Tension may be applied to the heated bundle to reduce the diameter of the bundle.

Abstract: Disclosed is a method of fabricating electronic components on a semiconductor substrate by etching features in the substrate through a mask including apertures which are separated by a prescribed spacing. Etching is continued until the etched features merge into a single channel. This technique can be used to form channels having nonuniform shapes, or could be used to monitor the end point of an etching operation.

Abstract: A retainer assembly for releasably securing an integrated circuit package to a circuit board for testing purposes includes an insulative plate having a central aperture which surrounds the package and captures the package leads between the plate and the circuit board with the leads in conductive engagement with respective conductive contact lands on the circuit board. Screws extending through openings in the plate and the circuit board are threadingly received in nuts secured to the underside of the circuit board to releasably secure the plate with the captured integrated circuit package to the circuit board.

Abstract: Laser apparatus for delivering optical power to an output port comprises first and second fiber lasers having at least partially overlapping cavity resonators. In one state the lasers are phase locked; in another they are not. An intracavity polarization transformer (e.g., a polarization modulator or a segment of PMF) determines the phase state of the apparatus. In each state the reflectivity of a reflector common to the lasers determines the amount of optical power which is delivered to the output port. In one embodiment the apparatus has a plurality of output ports to which separate utilization devices are coupled. The phase state of the lasers and the reflectivity of the common reflector determines how the optical power is allocated among the devices.

Abstract: The present invention provides an apparatus and method for a single-source wavelength division multiplexed (WDM) signal. According to the invention, light from a broad wavelength bandwidth or multiwavelength source is delivered, over one or more input optical fibers, to a device for spatially separating the light into a plurality of spectral components each having a different wavelength. The device further directs the spectral components along separate optical paths. A modulator array is provided containing a plurality of optical modulators spaced to each receive one of the different spectral components. Information is encoded on each spectral component through the action of each modulator. The encoded spectral components originating from a given input fiber are combined to generate a multiplexed optical signal.

Abstract: Thin film transistors in which the active layer is a film of an organic semiconductor with a structure having two or three six-membered, fused aromatic rings with two five-membered, heterocyclic aromatic rings fused thereto. The five-membered rings are either substituted or unsubstituted. If substituted, the substituents are either alkyl or alkoxyalkyl with about two to about 18 carbon atoms. The organic semiconductor compound has a field-effect 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. Thin film devices made of these materials have an on/off ratio of at least about 100.

Abstract: The specification describes fiber laser devices with cores containing aluminum in which the composition of the core is modified to minimize the core .DELTA., thereby allowing a larger core diameter, and a reduction in the fiber laser length by a factor equal to the square of the diameter difference. This result is achieved by compensation doping the core with phosphorus to offset the index-modifying contribution of aluminum.

Abstract: A method of depositing aluminum or other metals so that vias are more completely filled is disclosed. The wafer or substrate is preheated to a temperature of approximately 200.degree. C. Then the wafer is placed in an ambient of approximately 350.degree. C. while metal deposition commences. The resulting metal layer has a gradually increasing grain size and exhibits improved via filling. Also disclosed is a method and apparatus (involving cooling of support structures) for deposition of an anti-reflective coating to prevent rainbowing or spiking of the coating into the underlying metal.