Abstract: A clamp for seating a circuit card assembly (CCA) in a chassis, and for thereafter establishing thermal contact between the CCA and the chassis, includes a shaft and two wedges that extend substantially the length of the CCA. One wedge is affixed to the CCA and the other wedge moves laterally relative to the fixed wedge to expand the width of the two wedges and thereby urge thermal contact between the CCA and the chassis. The shaft is disposed in mating slots in the sliding faces of the two wedges and is joined to the fixed wedge to seat the CCA in the chassis by threading the shaft into the chassis, without effecting lateral expansion of the wedges. A flanged nut on the shaft may thereafter be used to effect longitudinal movement of the free-floating wedge to laterally expand the two wedges without affecting CCA seating.

Abstract: A waveguide able to operate at frequencies above 20 GHz is embedded in a printed wiring board. The waveguide is formed by evacuating a waveguide path through one or more dielectric layers of the board and joining the layers. After the layers are joined, the waveguide cavity is electroless copper plated by providing an electroless plating solution in the cavity. Thereafter, the cavity walls are electroplated to form seamless electrically conductive walls for the waveguide. A dielectric may also be provided in the cavity if desired. Electronic components may be formed in the waveguide by evacuating one or more layers of a printed wiring board in a similar manner, interconnected to the waveguide. In one embodiment, the components may convert the frequency of the signal carried in the waveguide so that higher frequency signals are processed within the RFI EMI protection of the layers of the wiring board.

Abstract: A system and method for estimating the number of emitters having wavefronts impinging on an array of m sensors may be used in the presence of correlated, unequal-level, as well as uncorrelated, equal-level noise. In the invention, the m eigenvalues of the sensor correlation matrix are evaluated to determine whether they are related to noise or to signals. Each eigenvalue, scaled by the estimated noise power level, is compared to the arithmetic mean of the preceding noise eigenvalues to determine whether the difference is enough to indicate the presence of a signal. Similarly, the successive slopes (differences between each scaled eigenvalue and its predecessor) may be compared to the arithmetic mean of the preceding slopes to make the determination. In an alternative embodiment, the eigenvalues are desensitized by increasing each by an amount not much larger than the first noise eigenvalue.

Abstract: A method of estimating both atmospheric conditions and surface temperatures of an object from either a single set of multispectral images or multiple simultaneously-acquired single-band images of the object. Estimates of atmospheric conditions are generated by determining and radiometrically correcting radiance values measured from the image of the object. Expected radiance values are then determined and compared with the measured radiance values. The best fit of the radiance values measured from the image of the object to the expected radiance values corresponds to the best estimate of the atmospheric conditions associated with the object. The present method estimates atmospheric conditions for the object regardless of the availability of atmospheric conditions associated with the image.

Abstract: A system for accurately locating a mobile cellular radio includes plural radio receivers, the position of each being precisely known, a satellite-based time source for providing the actual time of arrival of a radio signal at the plural radio receivers, and a device for removing multipath and cochannel interference from the received signals so that actual time of arrival of the radio signal may be determined accurately. The Global Positioning System (GPS) may be used to provide the time signal and to provide the precise location of the plural radio receivers. The system may be used to passively determine the location of the mobile radio and is accurate enough to use with a computer generated map system.

Abstract: To prepare a metallic surface for adhesive bonding, surface irregularities and contaminants are removed. This first step is followed by repeated cleaning of the metallic surface with a solvent and testing of the metallic surface for uniformity. Next, new surface material is exposed by blasting or abrading the surface material. Subsequently, the surface is cleaned and again tested for uniformity. Finally, the surface is treated with a silane solution and dried prior to bonding.

Abstract: A method of manufacturing a three-dimensional fiber-reinforced part utilizing the single-tool method of stereolithography. The tool is fabricated by designing the tool on a computer-aided design system and curing successive layers of a fluid medium via a computer-controlled irradiation source to form the three-dimensional tool. The desired part is generated by applying layers of resin-wetted fabric to the tool, curing the fabric on the tool, removing the tool from the designed part and cleaning, trimming and inspecting the designed part.

Abstract: A ferrule for supporting a wiring harness or a piping part on a host structure includes a base member mounted to the host structure, and a support member engaging the base member. The support member includes an aperture for receiving the wiring harness or piping part. The support member may include a dovetail- or T-shaped protuberance, and the base member may include a corresponding dovetailor T-shaped slot for receiving the protuberance for detachably mounting the support member to the base member.

Abstract: A heat transfer device and method may be used to conduct heat from a heat source to a heat sink. The device and method improve thermal conduction in composite material mounting boards for heat generating components. The composite material fibers in the board may be parallel to the mounting surface of the board throughout their length. The matrix material for the composite material may be a metal, such as aluminum, that has some capacity to conduct heat. The device may include at least two thermally conductive wedges in the board for conducting heat into and out of the interior of the board. The wedges and the metal matrix may be the same conductive metal. A plurality of the fibers and the metal matrix contact both wedges to conduct heat to a surface adapted to transfer heat to the sink. A method of manufacture of the device provides that the wedges may be formed by placing the fibers in layers having decreasing lengths and adding the metal matrix material.

Abstract: A method and apparatus for communicating synchronous and asynchronous data among multiple devices which are connected by a common network or a set of connected networks using a network communications protocol which provides deterministic, bounded latency. Transmitting and receiving devices communicate asynchronous data signals using data packets in accordance with the communications protocol in use by the system. If synchronous data signals must be communicated between two devices the transmitting device sends asynchronous data signals to the receiving device(s) to indicate that synchronous data will follow, and to inform the receiving device(s) of the transmitting device's address. The receiving device sets up a message filter which looks for and accepts data packets bearing a destination address field value equal to the address of the transmitting device.

Abstract: Monolithic microwave integrated circuit (MMIC) technology is advantageously used to fabricate microwave circuitry for an antenna-converter system to enable an antenna and its associated converter circuits to be integrated together into a unitary package. Small reliable radio frequency (RF) circuits, polarization switch matrix circuits, intermediate frequency (IF) circuits and power and control circuits for the converter are manufactured and integrated onto a plurality of small area microwave circuit disks using MIC/MMIC technology. The plurality of converter circuit disks are sandwiched together and directly mounted flat against the back of the antenna to form a unitary package. The disks for the converter circuits are further sized such that the circuit disks fit within an envelope volume defined by the size and shape of the antenna.

Abstract: There is described a method and apparatus for reducing the infrared emissions from a tail-pipe section of a jet engine. The apparatus consists of a plurality of overlapping hollow panels each having a truncated cone shape supplied with a liquid coolant such that the coolant absorbs heat from the surfaces of the panels and converts the liquid to a vapor. The vapor created by this heat absorption is injected from an end opening of a panel between the panels and the exhaust gases of the jet engine to form a boundary layer. Surrounding the panels is an outer cowling defining a chamber with the overlapping panels and containing a liquid coolant.

Abstract: A tapered thermal substrate for transferring heat generated from a heat source to a heat sink comprising a composite core of parallel layers of thermally conductive fibers, the core having a tapered edge that maximizes fiber end exposure to the heat source or sink. The tapered edge is comprised of at least one angled surface formed by machining the composite core. A copper thermal tab is plated to each angled surface and machined to a desired size and shape to provide a contact surface for the heat source or sink and a means for facilitating transfer of generated heat to and from the fiber ends. A flashing of a thin coating of copper and nickel over the composite core and each copper thermal tab is also provided to environmentally seal the composite core.

Abstract: A sensitive circuit area on a circuit board is isolated from an adjacent located non-sensitive circuit area by surrounding the sensitive circuit area with electrically interconnected ground planes positioned on the opposite sides of the circuit board. The isolation system further includes a "clam shell" RF/IF tight shield attached to each side of the circuit board enclosing the sensitive circuit area. A partially conductive gasket is placed between the clam shell and the top and bottom circuit board surfaces to enhance isolation performance.

Abstract: An adaptive matched filter is described as a replacement for a signal replica filter of a maximum likelihood (ML) demodulator, the filter normally receiving an input data vector having signal and noise components. A symbol-justified input data vector is produced from the input data vector. This vector is then used to generate a weight vector. In a time-domain embodiment, the symbol-justified data vector is multiplied by the weight vector on a symbol-by-symbol basis to estimate the signal components of the output of a filter. In a frequency-domain implementation, multiplication is carried out on a symbol block-by-symbol block basis.

Abstract: A frequency agile homodyne full duplex FSK system having a receiver section using an image-cancellation mixer wherein sum and difference signals generated by a pair of double-balanced mixers are added together with proper phase to cancel out the image response normally associated with heterodyne receivers and directly down-convert the carrier frequency to the baseband frequency. The transmitter section of the FSK system consists of an FSK modulator whose peak deviation is controlled by an active derivative of a crystal clock. The FSK modulator functions in the manner of a phasing single sideband (SSB) mixer with upper or lower sideband signals generated by the proper phasing of quadrature components of the carrier frequency and the peak deviation signal derived from a crystal clock.

Abstract: A streamlined housing for supporting a multi-dimensional electromagnetic transducer array is attached to an aircraft fuselage via a pivot support. The streamlined housing is supported by the pivot support in a torsionally unrestrained manner allowing a plane containing the longitudinal axis and pivot axis of the housing to remain substantially parallel to the plane of an incident airstream. Static aeroelastic stability is provided by mounting to the aft portion of the streamlined housing one or more rigidly attached stabilizer fins. Dynamic aeroelastic stability is provided by incorporating within the streamlined housing an adjustable ballast weight.

Abstract: The wave type, orientation and rotation of an incident electromagnetic signal having an unknown polarization is identified through single channel frequency domain signal analysis of the incident electromagnetic wave power as measured by an orthogonally polarized electromagnetic sensor. A controlled switch samples between the power measurements at each orthogonal output of the sensor to generate a signal comprised of a carrier frequency component and two sideband frequency components in the frequency domain. The sampled radio frequency signal is down converted by a single channel receiver to an intermediate frequency where the carrier and one sideband frequency component are separated and coherently shifted to the same frequency. A phase detector and ratiometer measure the relative phase and amplitude differences between the separated carrier and sideband frequency components to identify the wave type, orientation and rotation of the incident electromagnetic signal.

Abstract: Wireless electromagnetic communication between a primary transceiver and one or more secondary transceivers located within an enclosed structure may be effectuated by forming a multi-conductor electromagnetic transmission line within the structure. Communications are effectuated by utilizing the enclosing structure itself as one conductor in a multi-conductor transmission line. One or more other conductors are then placed within and insulated from the structure to complete the communications transmission line. A primary communications transceiver and a matched terminating load are connected to the ends of the transmission line to form a contained electromagnetic field. Use of a matched terminating load minimizes standing waves and provides for substantially constant electromagnetic field strength within the structure.

Abstract: The present invention provides a read-write head for an optical tape recorder comprised of a synchronized scanning transmissive polygon and rotating lens wheel. The transmissive polygon is a multi-sided piece of transparent optical quality material for displacing a through transmitted collimated read or write light beam. The lens wheel comprises a unitary disk-shaped piece of optical quality material having a plurality of individual lenses precision molded or diamond point turned therein for focusing the through transmitted and displaced read or write light beam onto a recording media. The polygon is rotated to translate the displaced beam for scanning along a linear path aligned with an arcuate path followed each successive lens on the rotating lens wheel. The rotation of the polygon and lens wheel are synchronized such that each scan of the displaced beam along the linear path coincides with the movement of a lens along the arcuate path to trace out a data track on the recording media.