Abstract: A dual phased array payload (100) for use onboard a communications satellite is disclosed. The payload includes one or more phased array receive antennas (102-108) including numerous individual receiving elements distributed in a predetermined configuration. Each of the individual radiating elements is selectively adjustable in amplitude and phase to achieve scanning beams for receiving information transmitted from the ground in an uplink beam. The payload includes a packet switch (114) connected to the phased array receive antennas (102-108). The packet switch (114) includes a set of inputs and a set of outputs. The set of inputs are selectively connectable to the set of outputs. The payload (100) includes one or more phased array transmit antennas (120-126) connected to the packet switch (114). The phased array transmit antennas (120-126) include numerous individual radiating elements distributed in a predetermined configuration.

Abstract: A system and method are set forth for photoacoustical analysis of isotope and other compounds having telltale absorption wavelengths between 1700-2500 nm. The system and method includes a Co:Mg F2, an optical parametric oscillator (OPO), or a diode laser tunable between 1700-2500 nm which is directed into a sample at energies sufficient to generate detectable acoustical emissions. A microphone detects the emissions for processing and analysis. The system and method is adapted to detect stable isotope compounds such as 13CO2 as well as other chemical compounds. For non-gaseous compounds, a CO2 or diode laser is used to photoablate the gaseous sample containing the suspected compound.

Abstract: A solder material 10 suitable for fluxless soldering attachment of a component 12 to a substrate 14 in a microelectronic assembly 16 such as a hybrid package comprises a core 18 and a gold layer 20 on the core. The core can comprise an alloy of tin and lead. The core preferably consists essentially of at least about 30 wt. % tin and the balance lead, so that it melts at temperatures of less than about 250° C. The gold layer is preferably applied to the core using an electroless plating process that forms a highly uniform gold layer. The solder material provides a joint between the component and the substrate comprising less than about 3 wt. % gold.

Abstract: A demodulation system used in connection with an analog optical link that provides a wide dynamic range and SNR potential for large RF signal bandwidths. An optical carrier signal modulated with an RF signal is applied to an optical splitter in the demodulation system that splits the signal into first and second carrier signals. One of the carrier signals is applied to a coarse demodulator that provides either PM or FM demodulation to generate a demodulated signal representative of the signal that includes the RF signal and the additive inverse of an error signal. The output from the coarse demodulator is inverted, and integrated in the FM case, and then applied to a phase modulator along with the second optical carrier signal from the optical splitter.

Abstract: A system for testing a communication satellite having multiple receiver channels (12), wherein a processor (20) normally used for other satellite functions is also used load and execute a testing module stored in an onboard memory (22). Under control of the testing module, a synthesizer (24) generates test signals and applies them through a controllable switch (30) to a selected receiver channel (12). The test signals are then analyzed by the processor (20) after passing through the selected receiver channel (12) under test. The analysis includes fast Fourier transform (FFT) processing to analyzed channel performance in the frequency domain. An additional feature of the invention allows multiple transmitter channels (46) to be analyzed in turn by a similar technique.

Abstract: An H-plane waveguide probe includes a microstrip formed on a dielectric substrate with a loop conductor generally configured in the shape of waveguide on one side and adapted to capture an incoming H-plane signal. A transition conductor formed on an opposing side of the substrate with a first leg and a second leg, connected together by a bend portion. The first leg of the transition conductor is generally parallel to the H-plane for coupling microwave energy from the waveguide to the microstrip. The second leg of the transition conductor is parallel to the E-field and is used to change the direction of the captured microwave energy along the H-plane direction to the E-plane direction. In order to optimize power transfer, the impedance of the loop conductor is selected to be about the same as the waveguide. The transition conductor is used to convert the E-field energy to a 50&OHgr; impedance, for example, for connection to an external microwave circuit.

Abstract: A field effect transistor with a double sided airbridge comprises a substrate containing a conductive region and source, drain and gate electrodes disposed on the substrate. The gate electrode has a finger portion with a first end secured to the substrate between the source and drain electrodes and a second end, and a double sided airbridge portion flaring outwardly from the second end and having opposed first and second extremities. A first gate pad is disposed on said substrate outwardly from the source electrode and is connected to the first extremity. A second gate pad is disposed on said substrate outwardly from the drain electrodes and is connected to the second extremity. The gate pads serve to support the airbridge gate finger so as to reduce stress on the gate finger. The first and second gate pads receive and transmit signals through the airbridge and to and from the gate finger.

Abstract: A multifunction antenna feed structure (30) that acts as a feed for a multibandwidth antenna system (22) used in connection with a modern tactical aircraft. The feed structure (30) includes a first feed (32) and a second feed (34) electrically connected to first and second feed points on an antenna element (24) at a location where the first feed (32) is impedance matched to the VHF/FM and UHF frequency bands and the second feed (34) is impedance matched to the VHF/AM frequency band. The first and second feeds (32, 34) are positioned within a flared notch (28) between the antenna element (24) and a conductive aircraft structural component (26). The feeds (32, 34) can take on different geometrical configurations, such as cylindrical feeds, cone feeds or taper feeds. The feeds are (32, 34) electrically isolated from conductive aircraft component (26) and are electrically connected to a matching network (70, 80).

Abstract: A vibration control system is provided for an appendage such as an antenna 10 coupled to a platform such as a spacecraft 12. The antenna 10 is coupled at a base 14 so as to extend from the spacecraft 12. A plurality of guidelines 20 extend between remote portions 22 of the antenna 10 and the antenna base 14. A plurality of motion control elements 36 are provided within the antenna structure for reducing oscillation settling time of the antenna 10 relative to the spacecraft 12. The motion control elements 36 include a material disposed therein having its damping response changed according to the magnitude of an electric or magnetic field applied thereto.

Abstract: A vibration control system is provided for an appendage such as an antenna 10 coupled to a platform such as a spacecraft 12. The antenna 10 is coupled at a base 14 so as to extend from the spacecraft 12. A plurality of guidelines 20 extend between remote portions 22 of the antenna 10 and the antenna base 14. A plurality of motion control elements 36 are provided within the antenna structure for reducing oscillation settling time of the antenna 10 relative to the spacecraft 12. The motion control elements 36 include a material disposed therein having its damping response changed according to the magnitude of an electric or magnetic field applied thereto.

Abstract: A spacecraft propulsion module (16) that includes an outer cylindrical housing (20), an end wall (22) and a specialized internal structure (50) that is capable of supporting various spacecraft components (110, 112, 124), to provide different levels of spacecraft complexity for different missions. The internal structure (50) within the housing (20) includes a plurality of inner walls (52-58) defining an “eggcrate” structure. The plurality of inner walls (52-58) includes a first pair of walls (52, 54), extending in one direction and a second pair of walls (56, 58) extending in a substantially orthogonal direction to define a center compartment (76) surrounded by a plurality of perimeter compartments (60-74).

Abstract: The reflective mesh material that forms the reflector in a foldable perimeter truss antenna is remotely adjusted to shape using remotely controlled stepper motors carried on the truss. Connected to the end of the catenaries, which shape and support the pliant reflective mesh material on the truss, the stepper motors adjust the tension on the catenaries and thereby change its shape. An RF receiver and electronic controller associated with each stepper motor receives the tension command information from a remote source and controls the stepper motor in accordance with that information.

Abstract: Adding a quantity of metallic shot or particles of other materials having a high dielectric constant to the thermoplastic paint in the mixing pot of ordinary roadway marker fixation equipment, which extrudes the paint and applies same to the roadway surface, enhances the MMW radiometric visibility of the marker without adverse effect to the affixation equipment. Vehicles containing MMW radiometers directed down toward the roadway surface moves along the roadway surface is able to automatically sense microwave/millimeter wave energy from a marker in the vehicles path. In one system, the sensed energy is used in conjunction with other apparatus to assist to guide the vehicle within a traffic lane. In another system, the sensed energy is decoded and displayed as pertinent information for the vehicle's driver.

Abstract: A technique for automatically identifying clusters of data from a set of data samples, by employing multiple morphological operations of a grid of data cells representative of the data samples. The data samples are stored (12) in the data cell grid (56) as binary quantities of which the position in the grid represents each multivariate data point. Potential cluster regions are identified by first performing a series of dilation steps (22) on the data grid, to expand contiguous regions covered by the data points until smaller regions merge into larger ones that are identified as the potential cluster regions. Then a series of erosion operations (26) is performed, shrinking the contiguous regions until smaller isolated regions are completely eliminated and thin linkages between other potential cluster regions are removed. Next, a further series of dilation operations (30) expands the contiguous regions again, to reconnect any potential cluster regions that were fragmented in the erosion operations.

Abstract: A high frequency coaxial interconnection solder ball grid array produces a low loss, reproducible electrical interconnection at the circuit board level for mounting one or more high frequency components, such as high frequency IMA modules. Since the coaxial interconnection ball grid array can be and is generally implemented as part of a larger ball grid array, high frequency signal generation, signal reception and digital processing can be combined in a single electronic component, such as a circuit board. A coaxial-like interconnection is formed from a plurality of solder balls configured in a three-by-three square array. The coaxial interconnection solder ball grid array includes a single centrally disposed solder ball for interconnecting with a centrally disposed conductor of a coaxial line and a plurality of solder balls surrounding the single centrally disposed solder ball, some balls of which interconnect with a coaxial ground shield of the coaxial line.

Abstract: Modular control patches including assemblies of sensors and actuators are provided to impart or control vibration of foundation members such as struts in aerospace apparatus. Local analog electronic control means is associated with each control patch assembly. Patches are attached mechanically or by chemical bonding to the outside of the struts. The corresponding electronics can be selectively removed and replaced. The patch being the sensors and actuators may also be attached or embedded with a composite structure.

Abstract: The invention relates to an optical integrated circuit microbench system for accurately aligning optical fiber and waveguides to efficiently couple energy between optical devices. This is accomplished by using the anisotropic etch characteristics of III-V semiconductor materials in two orthogonal directions. One etch direction serves to provide a channel for precise fiber-positioning; the other direction, which is orthogonal provides a reflecting surface for directing the optical energy onto optical devices.

Abstract: A SNS Josephson junction (10) is provided for use in a superconducting integrated circuit. The SNS junction (10) includes a first high temperature superconducting (HTS) layer (14) deposited and patterned on a substrate (18), such that the first HTS layer (14) is selectively removed to expose a top surface of the substrate (18) as well as to form an angular side surface (22) on the first HTS layer (14) adjacent to the exposed top surface of the substrate (18). Ion implantation is used to form a junction region (12) having non-superconducting properties along the angular side surface (22) of the first HTS layer (14). A second HTS layer (16) is then deposited and patterned over at least a portion of the first HTS layer (14) and the exposed top surface of the substrate (18), thereby forming a SNS Josephson junction.

Abstract: A tripropellant coaxial pintle injector for a rocket engine which enables smooth transitioning between two types of propellants that are adapted to be alternatively mixed with a third type of propellant in a combustion chamber of a rocket engine. The tripropellant coaxial injector includes a pintle for expelling a first propellant into a combustion chamber in a generally radial direction and two or more concentric metering sleeves which define orifices for expelling two or more different propellants into the combustion chamber in an axial direction thus, such a configuration allows for alternative mixing of two propellants with a third propellant in the combustion chamber of a rocket engine.

Abstract: A high-temperature (10 K) superconductive integrated circuit has a ground plane (2), an interlevel dielectric (6), and a low value resistor (18) to provide conductive paths to reduce parasitic circuit inductances, thereby increasing the speed and performance of the integrated circuit. The circuit also includes a high value resistor (20) connected between interconnect wires (34) to produce a desired resistance with a short distance between the interconnect wires (34), thereby significantly reducing the circuit area.