Abstract: CO.sub.2 jet spray cleaning apparatus that monitors CO.sub.2 snow plume characteristics. The present invention is a CO.sub.2 jet spray cleaning system that comprises a holding tank for containing liquid CO.sub.2, a spray nozzle coupled to the holding tank, a valve coupled between the holding tank and the spray nozzle, and a temperature sensor coupled to the nozzle for sensing the temperature of a plume of CO.sub.2 that is sprayed by the nozzle and for providing a signal indicative thereof. The system may also comprise a display coupled to the temperature sensor for displaying the temperature of the plume of CO.sub.2 to an operator, or an alarm coupled to the temperature sensor for alerting an operator that the temperature of the plume of CO.sub.2 has risen to a predetermined level. Either the displayed signal or the alert signal indicates that the quality of the plume has diminished and that the liquid CO.sub.2 in the holding tank should be replenished. The present CO.sub.2 jet spray cleaning system and CO.

Abstract: Methods and systems for encoding a video signal into a bit stream, and for reconstructing the video signal from the bit stream are disclosed. In an embodiment of an encoder, an object encoder (22) assigns a symbolic code to an object contained in at least one video frame, wherein the symbolic code identifies a corresponding generic object from a set of generic objects. A difference processor (32), coupled to the object encoder (22), computes a difference signal in dependence upon a difference between the object and the corresponding generic object. A multiplexer (30) provides the bit stream based upon the difference signal and the symbolic code. In an embodiment of a decoder, a demultiplexer (82) extracts a symbolic code and a difference signal from the encoded video signal. The symbolic code identifies a corresponding generic object from a set of generic objects, and the difference signal represents a difference between an object and the corresponding generic object.

Abstract: A simple robust sensor probe for determining the magnesium concentration in molten metal alloys in real-time. The probe provides needed process control information in molten metal technologies and has particular application to processes for removing magnesium impurities from scrap aluminum. The probe employs a specially constructed electrochemical concentration cell adapted for repeated immersions into vessels containing molten metal alloys. Specifically, the probe comprises two electrodes, both inert to a molten salt layer, to the molten metal (aluminum), and to magnesium. One electrode comprises an inverted molybdenum cup, a magnesium reference material, and a fibrous ceramic wick, e.g., yttrium oxide, for retaining molten salt therein in contact with the magnesium reference material when the sensor probe is first inserted into the molten salt layer and then into the molten aluminum layer.

Abstract: A FIM system integrates data from a plurality of interconnected local databases to provide users with access to a virtual database. The FIM includes a user interface for generating a global query to search the virtual database, a smart dictionary database (SDD) that contains configuration data, a data information manager (DIM) that decomposes the global query into local queries, and a plurality of local information managers (LIMs) that execute the local queries to search for and retrieve data from the enumerated databases. A filter generates a list of those local databases that contain information relevant to the global query. As a result, the DIM only generates local queries for the enumerated local databases. An input translator converts the global query into the respective local formats for the local databases so that the FIM provides true integration of heterogeneous databases.

Abstract: Contaminants are cleaned from the surface of a body in space by generating a substantially space-charge neutral reactive plasma, directing the plasma onto the contaminated surface at an energy below the surface sputtering energy (typically 20 eV), and reacting the plasma with the contaminants to remove them. A helicon wave plasma source is made light weight and compact enough for spacecraft use, with a plasma energy low enough to avoid damaging optical surfaces, by using permanent magnets to establish a static axial magnetic field, and a simple but novel rf antenna design. The antenna consists of a pair of spaced conductive rings which extend around the plasma tube, with conductive base and rf feed bars extending between the rings on diametrically opposite sides. The feed bar is interrupted to provide an rf input on opposite sides of the interruption. The antenna is preferably formed as an integral metal unit, with its rings rigidly supported by and integral with opposite ends of the base bar.

Abstract: A linear systolic array of computation cells, each cell having several vector rotation stages. These stages are programmable to provide efficient implementation of a variety of matrix algorithms. All data movement between cells is via parameterized data packets, and the full linear systolic array is completely data flow driven at the packet level. Physical computation cells can be mapped to act as one or more logical computation cells, allowing a small array to function logically as a larger array through a logical folding. This mapping also allows defective cells to be bypassed for fault tolerance. The array can be used to compute adaptive weights in digital beamforming radar applications.

Abstract: A microwave/millimeter wave circuit structure supports discrete circuit elements by flip-chip mounting to an interconnection network on a low cost non-ceramic and non-semiconductor dielectric substrate, preferably Duroid. The necessary precise alignment of the circuit elements with contact pads on the substrate network required for the high operating frequencies is facilitated by oxidizing the interconnection network, but providing the contact pads from a non-oxidizable material to establish a preferential solder bump wetting for the pads. Alternately, the contact bumps on the flip-chips can be precisely positioned through corresponding openings in a passivation layer over the interconnection network. For thin circuit substrates that are too soft for successful flip-chip mounting, stiffening substrates are laminated to the circuit substrates.

Abstract: An apochromatic grism (42) includes a first prism (48) with a second prism (50) disposed adjacent to it. A grating (44) is adjacent to the front surface of the first prism (48) and the Abbe number and dispersion coefficient of the grating are chosen such that the primary and secondary angular spread for a given spectral band is approximately zero. The apochromatic grism is a simple and compact device with minimal amounts of residual chromatic and anamorphic aberrations.

Abstract: A satellite-based communication system providing high rate transfer of data between linked terminals. The system comprises a plurality of user terminals (VSAT's) that are linked by and that communicate with each other by way of a satellite-based relay system. A network control center provides configuration signals that control the satellite relay system and coordinate linking of terminals to each other. Frequency division multiplexing uplinks are used from the terminals and the network control center to the satellite relay system. Time division multiplexing are used on downlinks from the satellite relay system to the terminals and the network control center. Each user terminal comprises a data compression and decompression circuit, a transceiver, and an antenna for transmitting and receiving data to and from the satellite relay system. The satellite relay system comprises a satellite, a wide area antenna, a plurality of receive antennas, a plurality of transmit antennas, and a signal processor.

Abstract: A wide-bandwidth variable attenuator/modulator incorporating a region of material comprising a combination of a ferromagnetic/nonmagnetic material which exhibits a Giant Magnetoresistance (GMR) effect.

Abstract: A membrane probe (10) for simultaneously testing two or more columns or rows of integrated circuits (37) while still on the wafer (56) upon which they are manufactured includes a flexible visually clear and self planarizing membrane (18) having circuit traces (22). A substrate (12) on which the membrane (18) is mounted features parallel ports (14) corresponding to alternate columns or rows of circuit chips (37) on the wafer to be tested. Two such substrates (12,112) thus forming two alternately used probe test heads (10,110) are employed for testing each full wafer, one test head (10) containing ports (14) corresponding to one set of alternate wafer columns or rows, the other test head (110) containing ports (114) corresponding to the remaining interlaced wafer columns or rows. Probe contact pads (30) are electroplated on areas of the traces (22) so that the contact pads (30) are visually registrable through the substrate ports.

Abstract: A digital receiver apparatus and method, designed for multiple simultaneous users, digitizes a received analog RF signal and tunes to multiple desired frequencies of the received signal on a time division multiplexed basis. After filtering by a finite impulse response (FIR) filter that also operates in time division multiplexing for multiple service bands, the selected signals are digitally demodulated and signal processed, again on a time-shared basis. Different service bands are accommodated at the same time by separate FIR filters, each including a coefficient memory for its particular service band. The multiplexed frequency signal for each band is multiplied by the coefficients of its respective FIR filter memory in a common complex multiplier. The results are demultiplexed and directed to respective accumulators for decimation in accordance with the FIR coefficient characteristics.

Abstract: A projection cathode ray tube having an improved target assembly (22) for minimizing target tilt and hot focus drift is disclosed. The target member (24) is supported by a shaft screw (37) secured to a face plate (20) of the projection tube by an adjustment pad (58) external to the tube in cooperation with a biasing spring (46) internal to the tube that exerts a tensile load on the shaft screw (37). A shaft screw tapered shoulder (36) and threaded mounting stud (34) engage a tapered seat (32) and threaded mounting bore (30) of the target (24), with the taper angle (.theta.) common to the shoulder and seat calculated to maintain constant contact between the abutting surfaces of the shoulder (36) and the seat (32) during thermal expansion and contraction of the target member (24) and shaft screw (37).

Abstract: A high power, flip-chip microwave monolithic integrated circuit (MMIC) assembly (30) has a high power microwave monolithic integrated circuit (MMIC) having a surface with an active area (72) in which heat is generated. The assembly also has a host substrate (34). A thermally conductive bump (51) formed over the surface of the MMIC has a first portion (51') in close proximity to and in thermal communication with the active area (72) of the MMIC and a second portion (51") which is in close proximity to and in thermal communication with the host substrate (34). The second portion (51") of the thermal bump (51) has a greater cross-sectional area than the first portion (51'). A multi-layer, multi-exposure method of manufacturing the improved thermal bump (51) includes several steps. A plating membrane (80) is formed on a surface of the MMIC (32). A first layer of negative photoresist is applied to the surface of the plating membrane (80), and is exposed with a first masked pattern of light.

Abstract: An adaptive processor which uses the successive range and Doppler outputs of a conventional matched-filter to improve the signal-to-noise ratio for non white noise/clutter. The adaptive processor minimizes the output for a given range and Doppler cell with the constraint that the response to signals returning with specified range and Doppler offsets, with respect to the center of the range-Doppler cell, each have specified values. Weights are derived which can be applied to range-Doppler outputs in the neighborhood of the range-Doppler cell to minimize its output subject to the constraints. The weights depend on an estimate of the cross-covariance matrix of the various outputs of the range-Doppler cells that are to be weighted. The constraint parameters are specified in terms of the ambiguity function of the transmitted waveform.

Abstract: An integrated solar cell-bypass diode assembly is provided by forming at least one recess in the back (non-illuminated) side of the solar cell and placing at least one discrete low-profile bypass diode in respective recesses so that each bypass diode is approximately flush with the back side of the solar cell. Each bypass diode is bonded to the solar cell for anti-parallel connection across the solar cell. The back side of the solar cell is preferably formed with a honeycomb pattern of recesses to reduce the weight of the solar cell while maintaining mechanical strength. The recesses that receive bypass diodes preferably have a rectangular shape that better accommodates the bypass diode.

Abstract: A system and technique for measuring the thickness of an optical element. A first energy signal of a first phase is transmitted into the element. The first signal reflects off of a distal surface of the element and is detected as a return signal. The phase of the reflected signal is compared to the phase of the transmitted signal and the frequency varied to extract a third signal representing a desired phase difference therebetween. Corresponding frequency data are processed to determine the thickness of the element at the point of transmission of the first signal.

Abstract: A diamond matrix metallic mesh suppresses RF energy, and particularly side lobe energy, in a phased array antenna, while passing main beam energy. The metal mesh emulates the structure of the bond segments joining the carbon atoms in a diamond structure. The wire diamond lattice structure is placed above an array of radiating elements to absorb side lobe energy. The wire lattice structure is fabricated through use of complementary forms which compress a wire into a required unit shape. Many unit shaped wires are placed in a form which hold the wires in the proper position. Other unit shaped wires are rotated 90 degrees and attached in place to the held wires. Additional unit shaped wires are added to form the basic interlocking cube structure of the diamond lattice.

Abstract: Discrete carrier and lattice structures are bonded together to form a lightweight rigid solar panel. The carrier includes a pair of electrically inert face sheets bonded on opposite sides of a thin thermoconductive honeycomb core. The face sheets provide an electrically inert surface for receiving a solar cell array and the honeycomb core forms a heat sink for conducting heat away from the solar cell array. The lattice includes a pair of patterned face sheets having a high elastic modulus bonded on opposite sides of a lattice base. The patterned face sheets provide axial stiffness and the lattice base separates them to provide bending stiffness. By splitting the solar panel into discrete carrier and lattice components, the present invention reduces the weight of existing solar panels by approximately 40% and increases power efficiency by approximately 10%.

Abstract: A liquid crystal light valve is provided with an array of photoconductive pedestals surrounded by a dielectric matrix material. Metal mirror pads are formed on top of each pedestal to form a high resolution metal matrix mirror, with each pedestal/mirror combination servicing one image pixel. The dielectric matrix forms a potential barrier between the individual photoconductive pedestals which prevents lateral charge migration between pedestals. The metal matrix mirror also shields the underlying photoconductive pedestal from photoactivation by the readout beam. The dielectric matrix material has a lower dielectric constant than the photoconductive pedestals, allowing the impedance of the photoconductive pedestals to match the impedance of the liquid crystal layer with a much thinner layer of photoconductive material than in prior LCLVs using a continuous photoconductive layer.