Abstract: Ion erosion of grids is reduced in an ion thruster with a multiple-grid ion-optics system. The thruster has an array of aperture sets in which aperture areas change in a perimeter region of the array. In one ion-optics system embodiment, a screen aperture area is reduced and a decelerator aperture area is increased in aperture sets that are proximate to the perimeter of the array. Prototype tests of this embodiment have illustrated significant reduction of ion erosion.

Abstract: The disclosure describes a switchable optical delay device which is small, inexpensive, lightweight, has high cross-talk isolation, and is capable of sub-microsecond switching times. The delay device uses low-reflection terminations, a single input, and a single output to minimize cross-talk. The device is preferably integrated onto a substrate in either a trombone-shaped configuration or a more compact nested configuration.

Abstract: A system and a method of pumping a gain medium element in one or more stages of a laser amplifier or oscillator with a spatially inhomogeneous optical pump beam, to minimize the potential for parasitic oscillation modes and amplified spontaneous emissions. The method is preferably accomplished by generating a spatially modulated optical pump beam, and pumping the gain medium element with the spatially modulated optical pump beam, to optically fragment the gain medium element into discontinuous amplifying gain regions, thereby creating a very lossy configuration for undesirable lateral modes, while maintaining a high-gain path for the desired longitudinal mode of operation. If there is more then one amplifier stage, the substantially identical optical pump beams are used in each stage and the gain regions of one gain medium element are spatially mapped onto the gain regions of the subsequent gain medium element.

Abstract: An integrated circuit technology combines heterojunction bipolar transistors (HBTs), high electron mobility transistors (HEMTs) and other components along with interconnect metallization on a single substrate. In a preferred embodiment a flat substrate is patterned, using dry etching, to provide one or more mesas in locations which will eventually support HEMTs. A device stack including HEMT and HBT layers is built up over the substrate by molecular beam epitaxy, with the active HEMT devices located on the mesas within openings in the HBT layer. In this way the active HEMT is aligned with the HBT layer to planarize the finished integrated circuit.

Abstract: A device for implementing a multimedia communication dissemination system is disclosed herein. The communication system integrates heterogeneous satellite transmission systems, local area computer networks, and the public telephone system to implement a flexible, high-speed communication system. The preferred communication dissemination system includes a broadcast server for broadcasting an information signal, a mobile base station for receiving the information signal broadcast from the broadcast server, and a local area network for distributing information received by the mobile base station. The preferred mobile base station includes a receiver for receiving information signals transmitted from a broadcast server, a network interface for distributing processed information signals, and a software proxy process for processing information signals. A software proxy process controls the dissemination of information through the network.

Abstract: A composite particulate material for use in anodes of lithium-ion batteries. The particles of the material include a graphite core that has been provided with a surface layer including a non-graphitizable carbonaceous material. The graphite core having an interplanar spacing of at least about 0.346 nm. The method of producing the composite is also disclosed.

Abstract: A dual time delay interferometer (TDI) enables remote sensing of phase modulated information, such as the detection of ultrasonic vibrations from highly diffuse surfaces, preferably in the range from about 10 kHz to 100 MHZ or more. The system can also be configured in a transceive mode with a dual pass through a single TDI, which is well suited to optical communications. A non-steady-state photo-electromotive-force detector tracks the movement of interference fringes (whose position shifts as the surface vibrates), rather than their absolute position. A phased array of the sensors can be used for enhanced imaging applications requiring better signal/noise ratios, or alternatively, when lower power optical sources are employed.

Abstract: Various structures for cantilever beam tunneling rate gyro devices formed on a single substrate are disclosed. A cantilever electrode having a plurality of portions extending from the substrate with one end of the cantilever is suspended above the substrate at a distance from a tunneling electrode so that a tunneling current flows through the cantilever and tunneling electrode in response to an applied bias voltage. The cantilever and tunneling electrodes form a circuit that produces an output signal. A force applied to the sensor urges the cantilever electrode to deflect relative to the tunneling electrode to modulate the output signal. The output signal is a control voltage that is applied between the cantilever electrode and a control electrode to maintain a constant tunneling current. In the preferred embodiment, two cantilever portions extend from the wafer surface forming a Y-shape. In a further embodiment, a strap is fabricated on the cantilever electrode.

Abstract: A pollutant destruction apparatus has a corona discharge reactor attached to conductive end plates at the ends of the reactor. The reactor has inner and outer electrodes deposited respectively on the inner and outer surfaces of a hollow dielectric cylinder, the interior of which defines the reactor chamber. The inner electrode is electrically connected to the end plates, which are grounded, while the outer electrode is connected to a high-voltage power supply to establish a corona discharge. The outer electrode is tapered near the ends of the reactor to reduce the possibility of arcing. A hole in each end plate is aligned with the reactor chamber to allow gas flow into and out of the reactor.

Abstract: A photovoltaic device uses a spectrally selective photon partitioner such as a reflector to partition incoming sunlight which is directed towards different solar cells, depending upon its energy. Solar cells having low and high energy band gaps are used, in which low energy photons are imaged towards that cell having the lower energy band gap, whereas high energy photons are imaged towards the higher energy band gap cell. By more directly imaging photons towards those cells in which they are converted to electricity, absorption losses due to free carriers in the semiconductor layers are reduced. The spectrally selective photon partitioner allows semiconductor layers having different lattice spacings to be optically coupled.

Abstract: A method of detection and tracking of targets using multiple angle-only sensors is disclosed. The method is computationally efficient and is capable of detecting and tracking multiple targets in true three dimensional space. The method comprises distributing a set of modules in space and associating those modules with bearing lines from each sensor to each target. Through repetitive iterative associations between modules and bearing lines, the modules converge on the targets present.

Abstract: A membrane probe (10, 12, 14, 16, 58, 144) for testing integrated circuits (56,138) while still on the wafer upon which they are manufactured includes a flexible visually clear and self planarizing membrane (26) having circuit traces (20) and ground shielding planes (14), terminating resistor (152) and active buffer chips (172) formed thereon. Probe contact pads (36,38) electroplated on areas of the traces, and connector pads (32) plated on the membrane facilitate rapid detachable connection to a test fixture (50). The probe has a configuration, dimension and structure like that of the wafer itself so that automated pick and place equipment (136,142) employed for handling the wafers (138) may also be used to handle the probes (144). An unique test fixture (50) is adapted to receive and detachably secure a selected probe to the fixture.

Abstract: A workpiece is heated by first forming an ionized gas plasma around the workpiece. A positive potential is applied to the workpiece to accelerate electrons from the plasma into the workpiece. The workpiece is uniformly surface heated by the energy directed into the workpiece by the electrons. The workpiece is cooled by providing a flow of a pressurized liquid material such as carbon dioxide having a triple point. The liquid material is expanded through a nozzle to form solid particles that contact the surface of the workpiece and remove heat from it by subliming.

Abstract: An integrated circuit is protected from reverse engineering by connecting doped circuit elements of like conductivity with a doped implant in the substrate, rather than with a metallized interconnect. The doped circuit elements and their corresponding implant interconnections can be formed in a common fabrication step with common implant masks, such that they have an integral structure with similar dopant concentrations. The metallization above the substrate surface can be designed to provide further masking of the interconnects, and microbridges can be added to span strips of transistor gate material in the interconnect path.

Abstract: In a pollutant destruction apparatus with at least one corona discharge reactor, one or more inner electrodes are deposited on the interior dielectric surface of each reactor, preferably by metal vapor deposition, to provide structural support and heat dissipation for the inner electrodes.

Abstract: Wideband phased array antennas are provided that eliminate the need for phase shifters in the region of the array face. In addition, they generate less beam squint than conventional antennas. In one embodiment, they include an electronic signal generator, reference and scanning manifolds and an array of n radiative modules. The signal generator generates a variable-frequency scanning signal s.sub.s and a reference signal s.sub.r wherein the frequency of the reference signal s.sub.r is substantially a selected one of the sum and the difference of the frequencies of the scanning signal s.sub.s and an operating signal s.sub.o. The reference manifold receives and divides the reference signal s.sub.r into n reference signal samples which are progressively time delayed by a selectable one of m reference differential time delays .DELTA.t.sub.r. The scanning manifold receives and divides the scanning signal s.sub.

Abstract: A digital waveform generator reads out simulated .DELTA..SIGMA. ADC data for a desired periodic analog waveform from a memory and converts it, using a low-resolution high speed DAC, into a synthesized analog waveform. The .DELTA..SIGMA. digital waveform generator is preferably designed to take advantage of the natural evolution of device technologies. The memory is fabricated with older technologies, which tend to be slower but have a much higher integration. The DAC is implemented in more recent technologies, which are faster but have less integration. A speed up buffer or buffers in intermediate speed intermediate integration technologies may be included to provide a bridge between the low speed memory and the low integration DAC.

Abstract: Mixing and modulating methods are described for nonlinear optical amplifiers (30) which can generate intermodulation products of radio-frequency signals in an optical carrier signal (26) without the penalty of an optical conversion loss and without the need for radio-frequency mixers, electro-optic modulators and expensive polarization-maintaining optical fibers. The radio-frequency signals can be applied to either a bias port (36) or an optical input port (32) of the optical amplifier and are used to upconvert and downconvert signals in phased-array antenna and remote antenna embodiments of the invention.

Abstract: A plasma heating apparatus for heating a workpiece includes a chamber of sufficient size to receive a workpiece therein and a source of a reduced gas pressure within the chamber of from about 0.01 to about 100 millitorr. The plasma heating apparatus further includes a plasma source of an enveloping plasma. Optionally, a workpiece voltage may be applied between the workpiece and the wall of the chamber, and a source of a reactive gas can be provided to backfill the chamber, and radiant heaters can be provided to independently heat portions of the workpiece. In operation, the plasma source produces a plasma that surrounds and heats the workpiece. The plasma and the heating of the workpiece are tailored to achieve controllably uniform or nonuniform heat treatment and/or surface treatment of the workpiece.

Abstract: A pollutant destruction system connects a capacitive corona discharge chamber in a self-resonant circuit with an inductive element. Intermittent energizing signals are furnished from a power supply to induce corona discharges within the chamber, with the resonant circuit responding to the energizing signals by initiating additional corona discharges between energizing signals in a highly energy efficient operation. One or more discharge chambers can be provided in the resonant circuit, with each discharge chamber comprising a dielectric enclosure with a distributed electrode outside and an elongate electrode inside the enclosure. The inner electrode can extend either along the chamber axis, or along the inner chamber wall for better support and heat dissipation.