Abstract: A communication system and more particularly to a variable rate differential phase shift keying (DPSK) communication system with minimal hardware that does not have power or performance penalties associated with known DPSK modulation systems is disclosed. The DPSK modulation system in accordance with the present invention includes a transmitter, which includes a carrier signal source, a phase modulator and a DPSK encoder for modulating a carrier signal. The modulated carrier signals may be amplified, for example, in optical communication systems by a rare earth element doped fiber amplifier. The signals are continuously transmitted to a multi-rate receiver through a communication channel, for example, free space. The multi-rate receiver includes a single demodulator, for example, a single optical interferometer, used for multiple integer sub-harmonic data rates which demodulates the modulated signal.

Abstract: An alignment system for co-aligning multiple laser beams to a single spatial reference point in real time. The alignment system includes a beam sampler for sampling the multiple pulsed laser beams. The sampled laser beams are directed onto a quadrant photo detector or quad cell. The output signals from the quad cell are directed to a detector signal integration circuit which develops error signals for driving tip-tilt mirrors in the beam path of the multiple lasers. The system includes a gate, reset and pulse ID generator for generating pulse trigger signals for each of the multiple lasers and signals for correlating the detector signals with the laser that produced the signal. Accordingly, a system is provided for a time multiplexed, multiple laser system which automatically co-aligns the output beams from each of the lasers to a single spatial reference point in real time.

Abstract: A relatively simple and inexpensive process for plating precious alloyed metals, such as AuSn, AuSnIn, AgSn, AuIn and AgIn. Anodes are formed from each of the metal components in the alloy and disposed in a conducting solution. The mass of each metal components is determined by Faraday's law. The target is also disposed in the conducting solution. Plating current is independently applied to each anode. The plating is conducted under an ultraviolet light sources to optimize the process. The plating alloys can be used for various purposes including attaching a semiconductor die to a substrate. Since the process does not involve exposure of the semiconductor die to a relatively high temperature for a relatively long time, the process does not pose a risk of contamination of the semiconductor by the adhesive or wax used to hold the die in place on the carrier during processing.

Abstract: A tether system for a ball, such as a soccer ball, includes a simple swivel that is adapted to be connected directly to an extending tab on a ball. The swivel fastener is a two piece member. The two piece swivel is relatively less expensive than other more complicated swivel connectors, thus reducing the overall cost of the tether system. In addition, since the two piece swivel can be connected directly to on the ball, the tether system in accordance with the present invention also eliminates a process step of connecting the swivel to an intermediate ring, thus further reducing the cost of the tether system.

Abstract: An image processing system for use in development and playback of interactive video. In a development mode of operation, pixel or video objects are selected in a frame by way of a developmental graphical user interface. The system automatically tracks the selected pixel objects in the preceding and succeeding video frames by determining range limits for various color variables of the selected pixel object to compensate for the effects in lighting changes and decompression effects. The system automatically locates pixel objects within the calculated range limits in the preceding and succeeding video frames and generates a pixel object file which identifies the coordinates of the selected pixel object in each frame. The pixel object file is linked to a data object file which links the selected pixel objects to data objects. The pixel object file and data object file, collectively “linked video files,” are created during a development mode of operation.

Abstract: An apparatus and method that more effectively reduces fluid streaking in a motionless mixer includes a series of baffles, including a flow inversion baffle. The flow inversion baffle acts to redirect fluid from the center of the fluid flow stream to the periphery of the fluid flow stream while at the same time redirecting fluid flow from the periphery of the fluid flow stream to the center. The transposition of fluid flows eliminates the “channeling” effect and reduces streaking in the extruded mixture.

Abstract: A semi-physical device model for HEMTs that can represent known physical device characteristics and measured high frequency small signal characteristics relatively accurately. The semi-physical device model in accordance with the present invention uses analytical expressions to model the fundamental electric charge and field structure of a HEMT internal structure. These expressions are based on the device physics but are in empirical form. In this way, the model is able to maintain physical dependency with good fidelity while retaining accurate measured-to-modeled DC and small signal characteristics. The model in accordance with the present invention provides model elements for a standard small signal equivalent circuit model of FET. The model elements are derived from small signal excitation analysis of intrinsic charge and electric field as modeled within the device by the semi-physical HEMT model. As such, the RF performance can be predicted at arbitrary bias points.

Abstract: An ion source for ion implantation system and a method of ion implantation employs a controlled broad, directional electron beam to ionize process gas or vapor, such as decaborane, within an ionization volume by primary electron impact, in CMOS manufacturing and the like. Isolation of the electron gun for producing the energetic electron beam and of the beam dump to which the energetic beam is directed, as well as use of the thermally conductive members for cooling the ionization chamber and the vaporizer, enable use with large molecular species such as decaborane, and other materials which are unstable with temperature. Electron optics systems, facilitate focusing of electrons from an emitting surface to effectively ionize a desired volume of the gas or vapor that is located adjacent the extraction aperture. The components enable retrofit into ion implanters that have used other types of ion sources.

Abstract: A superconducting self-clocked complementary SFQ logic family. The basic element of the circuit is a plurality of Josephson junctions and a control inductance coupled across a pair of voltage rails. An important aspect of the invention relates to the use of voltage biasing for the Josephson junctions, which provides several benefits. First, voltage biasing eliminates the need for biasing resistors as used in constant current mode devices. Such biasing resistors are known to be the dominant source of power dissipation in such logic circuits. Elimination of the biasing resistors thus reduce the power dissipation to the lowest possible value to that of the power dissipation of the switching devices themselves. In addition, the voltage biasing takes advantage of the voltage to frequency relationship of Josephson junctions and automatically establishes a global clock at the Josephson frequency without the need for extra circuitry; thus increasing the practical clock rate.

Abstract: A computer system which includes one or more wireless interface devices that are adapted to communicate with a remote host over a radio link. Each of the wireless interface devices is a pen-based device which includes an ink field in which pen events are translated into pen data. packets and transmitted to the remote host over the radio link. Local inking is provided at the wireless interface device in order to maintain the pen paradigm in essentially real time.

Abstract: A compensation circuit for compensating for switching point errors in rotating target or gear tooth sensors. The compensation circuit may include a processing unit and a persistent storage device, such as an electrically erasable programmable read-only memory (EEPROM), for storing compensation values that are used to provide automatic compensation of the rotating target sensor after the sensor module is installed by the end user. The actual and compensation values may be determined and stored as linear functions in the form of mX+b, where X is the frequency of the rotating target, m is the slope and b is the y-intercept. In order to provide compensation, the actual slope value m is multiplied by a compensation value. The y intercept (i.e. b) is selected, for example, to be the maximum speed in a given application. The compensation values (i.e.

Abstract: A rotary position sensor is formed with a self-lubricating bearing. The rotary position sensor includes a race which forms one bearing surface. A drive arm assembly forms a bearing element forming two mating bearing surfaces. For applications in which the bearing may be subjected to environmental conditions that could result in corrosion, one bearing surface may be formed from a corrosion resistant metal, such as stainless steel, while the mating bearing surface is homogeneously formed with the bearing element from a composite material which includes PFTE or Teflon. By homogeneously forming the bearing element from a composite material which includes Teflon, wear of the bearing element will not effect lubrication of the bearing.

Abstract: A hybrid model formed from a semi-physical device model along with an accurate data-fitting model in order to implement a relatively accurate physical device model as a large signal microwave circuit computer-aided design (CAD) tool. The semi-physical device model enables accurate representation of known physical device characteristics and measured bias-dependent characteristics. This model is used to accurately simulate the effect of process variation and environmental changes on bias-dependent characteristics. The data-fitting model is used to model these characteristics with relatively good fidelity. The expressions of the model are constructed to be charge conservative. As such, the model is computationally robust within the harmonic balance algorithms employed by known large signal microwave circuit CAD tools.

Abstract: A rotary position sensor which includes a molded housing with a central aperture forming a drive arm cavity, a drive arm assembly and a rotor plate. The drive arm assembly carries a circular magnet and a shunt ring and is rotatably received within the drive arm cavity. The drive arm assembly is formed with an extending stud for connection to an external mechanical lever. The rotor plate is used to close the drive arm cavity and carries a magnetic flux responsive element and one or more flux concentrators and optional flux shunt. The molded housing, drive arm assembly and rotor plate are configured to minimize air space within the drive arm cavity after the sensor is assembled. By minimizing air spaces within the drive arm cavity, the amount of ice build up within the drive arm cavity is minimized. In addition, to further prevent a condition of ice lock of the drive arm assembly relative to the molded housing, all surfaces within the drive arm cavity are formed as smooth surfaces.

Abstract: An electronic circuit for automatically compensating for errors in the output signal of a displacement sensor. The electronic circuitry includes an analog to digital converter for converting an analog output signal from a linear displacement type sensor. The digital output signal from the sensor is processed by a microcontroller which automatically compensates for errors in the output signal. Ideal values, stored in an electronic memory, are used for compensation.

Abstract: An imaging or viewing system, which automatically compensates for bright spots, which tend to overload or saturate imaging system. The system can be used with imaging type tracking systems, viewers and various types of optical devices which heretofore have been unable to provide satisfactory performance due to saturation or overloading of an imaging device due to bright spots, i.e., laser radiation flares or sunlight. The system in accordance with the invention is configured such that reflected radiation is imaged onto a first image plane without dividing the incoming radiation into two optical paths. A digital mirror device, i.e., is disposed at the first image plane. The radiation level of each pixel in the image plane is compared with a fixed threshold on a pixel by pixel basis and used to generate a mirror drive signal that automatically reduces the reflectivity of the corresponding mirror pixel to compensate for bright spots.

Abstract: A semiconductor laser diode array including a plurality of laser diode bars, each carried by a submount and forming a subassembly. Each subassembly is separated by a flexible or compliant electrically conductive spacer. All connections within the array are by way of a non-fluxed solder, that may be hard and/or soft, reflowed in a non-oxidizing atmosphere in a simple mechanical stack fixture to create nearly void-free solder joints with relatively high thermal integrity and electrical conductivity. Flexible electrically conductive spacers are disposed between the subassemblies to eliminate tensile stress on the laser diode bars while providing electrical conductivity between subassemblies. The subassemblies are carried by a thermally conductive dielectric substrate, allowing waste heat generated from the bars to be conducted to a cooling device. The invention eliminates known failure modes in interconnections, minimizing tensile strength on the diode arrays, and increasing the useful life of the array.

Abstract: A nonlinear transmission-line waveform generator for generating a comb of frequencies and relatively short duration pulses, for example, in the range of picoseconds and tens of picoseconds, that are adapted to being utilized with ultra wideband radios in order to improve the bandwidth of such radios by an order of magnitude, for example, up to tens and even hundreds of GHz. In particular, the nonlinear transmission line waveform generator in accordance with the present invention consists of a microstrip or coplanar waveguide line. In accordance with an important aspect of the invention, the &Dgr;C/&Dgr;V characteristic of the nonlinear transmission line is matched to the frequency and amplitude of the input sinusoidal waveform.