Abstract: In a method for preserving an air bridge structure on an integrated circuit chip, a protective layer is plasma-deposited over the top and sides of the air bridge. A high density interconnect structure is applied over the chip and protective layer. The protective film provides mechanical strength during the application of the high density interconnect structure to prevent deformation. It also prevents any contamination from intruding under the air bridge. More importantly, the protective film only negligibly impedes the performance of the air bridge and therefore does not need to be removed, thereby eliminating the necessity of ablating the HDI structure.

Abstract: To control the transmission ratio of a continuously variable hydrostatic transmission including an input shaft, an output shaft, an pump unit driven by the input shaft, a grounded motor unit, and an a wedge-shaped swashplate drivingly and pivotally connected to the output shaft in hydraulic fluid-communicating position between the pump and motor units, a ratio controller is provided having a hydraulically actuated piston incorporated internally of the output shaft. A pilot valve, also incorporated internally of the output shaft, operates to create differential fluid pressures at opposite end faces of the piston, forcing axial motion of the piston and ratio-changing pivotal movement of the swashplate linked to the piston.

Abstract: HDI fabrication techniques are employed to form a variety of optical waveguide structures in polymer materials. Adaptive optical connections are formed, taking into account the actual position and orientation of devices which may deviate from the ideal. Structures include solid light-conducting structures, hollow light-conducting structures which are also suitable for conducting cooling fluid, and optical switching devices employing liquid crystal material. A "shrink back" method may be used to form a tunnel in polymer material which is then filled with an uncured polymer material that shrinks upon curing.

Abstract: A spacecraft (8) includes a movable appendage such as solar panels (12) operated by a stepping motor (28) driven by pulses (311). In order to reduce vibration andor attitude error, the drive pulses are generated by a clock down-counter (312) with variable count ratio. Predetermined desired clock ratios are stored in selectable memories (314a-d), and the selected ratio (R) is coupled to a comparator (330) together with the current ratio (C). An up-down counter (340) establishes the current count-down ratio by counting toward the desired ratio under the control of the comparator; thus, a step change of solar panel speed never occurs. When a direction change is commanded, a flag signal generator (350) disables the selectable memories, and enables a further store (360), which generates a count ratio representing a very slow solar panel rotational rate, so that the rotational rate always slows to a low value before direction is changed. The principles of the invention are applicable to any movable appendage.

Abstract: A device for converting a mid-wave infrared or long-wave infrared thermal image into a coherent near-infrared image includes a two-dimensional array of quantum-well-based optical modulators and infrared photodetectors. Each modulator is integrated or hybridized with a respective photodetector, and the combination is connected to an electronic circuit. Variations in mid-IR or long-IR light intensity are converted by each photodetector into variations in a bias applied to its respective modulator. The bias variations modulate the intensity and/or phase of near-IR light illuminating the modulators.

Abstract: A dual band IR scanning focal plane assembly includes two linear detector arrays in a close spaced configuration monolithically integrated on a common substrate. A medium wave IR staggered element linear array is formed on the front (111)B face of a (111) crystallographically oriented CdZnTe substrate in an MCT layer deposited by the molecular beam epitaxial (MBE) process. A long wave IR staggered element linear array is formed on the back (111)A face of the substrate in an MCT layer deposited by the liquid phase epitaxial (LPE) process. The sets of odd and even rows of the LWIR array on the back face are contiguous, while the sets of odd and even rows of the MWIR array on the front face are close-spaced, the spacing being just wide enough to allow a clear optical path to the underlying linear LWIR array. The arrangement provides simplified spectral separation of the simultaneously readout MWIR and LWIR images.

Abstract: The invention relates to a dual frequency sonar transducer assembly which may be operated at low and/or high frequencies in a sonar array. The assembly comprises a low frequency unit of tonpilz design including a low frequency driver, a low frequency tail mass and a composite head mass, the composite head mass acting as a single low frequency water driving piston and comprising a plurality of high frequency units forming individual high frequency water driving pistons. The high frequency units are also of tonpilz design, with independent drivers, independent head masses, and a common tail mass. The use of a common tail mass simplifies the design without compromising high frequency operation. The design leads to more efficient operation at both frequencies by minimizing the head mass to tail mass ratios.

Abstract: Weld filler alloys comprising aluminum, copper, lithium and, optionally, silver are disclosed which possess significantly improved fabricability and weldability. The weld filler alloys are free of magnesium and can be easily drawn into weld wire that is useful for welding aluminum-base alloys. Weldments made with the filler alloys exhibit highly improved mechanical, physical and corrosion resistance properties. The weld filler alloys may be used to weld cryogenic containers for space launch vehicles and the like.

Abstract: A compact dual band IR focal plane assembly provides simultaneous, coincident two-dimensional image readout. It includes a MIS-CID MWIR detector array formed in an epitaxial layer grown by the MBE process on the (111B) front face of an IR transparent crystalline first substrate, the pixels thereof forming LWIR transparent windows, with opaque connections thereto lying in aisles framing the windows, and a PV diode LWIR detector array formed in an epitaxial layer grown by the LPE process on the (111A) back face of the substrate, the LWIR pixels being aligned with the transparent MWIR pixels. An MWIR MUX is provided on an IR transparent silicon second substrate arranged in front of the first substrate. The opaque switch portion of the MWIR MUX is arrayed with apertures and aisles in alignment with the windows and aisles of the MIS-CID array.

Abstract: An improved x-ray detector in the form of a p-i-n CdTe homojunction device is disclosed. The intrinsic ("i") layer is of high resistivity CdTe, while the n- and p-doped CdTe layers are epitaxially grown in a photo-assisted process in a molecular beam epitaxial apparatus. The n-dopant is conveniently indium, with an indium metal contact. The "i" layer is optionally epitaxially grown in a photo-assisted process. The p-dopant is preferably arsenic. A PAMBE formed mercury telluride contact layer enhances the ohmic contact to the p-layer, and a gold contact is provided to the contact layer. The use of the PAMBE technique facilitates high quality crystal growth and activation of the dopants. The resulting CdTe p-i-n homojunction device has a wide band gap (1.45 eV) essential to room temperature operation.

Abstract: A thermally-actuated switch includes a pair of switch contacts openable or closeable in response to a change in the length of a shape memory metal (SMM) rod. The SMM rod is caused to change its length by having its temperature increased by heat produced when electrical power dissipated in a heating element that is coupled in electrical circuit with the switch contacts. To this end, the heating element is thermally coupled to the SMM rod, such as by a common heatsink. Where the switch is to be openable, the heating element is preferably in series circuit with the contacts, and where the contacts are closeable, the heating element is preferably in parallel therewith.

Abstract: The invention relates to apparatus for reducing the masking effect in the doppler frequency domain of wind sheared clutter upon the radar returns of moving targets. The invention consists in forming two beams from the elements of a radar antenna array by means of adjustable complex weights which are then summed. One of the two beams is then delayed by a predetermined amount and added algebraically to the other beam to form a composite beam containing a narrow trough-like depression in beam angle/doppler frequency space. Means are then provided for adjusting the weights to bring coincidence between the depression and the clutter to cause attenuation of the clutter with a minimum reduction in the usable doppler frequency domain.

Abstract: A structural panel has thin inner and outer facesheets bonded to a lightweight structural interior core of a honeycomb material. The inner facesheet is for receiving equipment that generates heat to be dissipated and the outer facesheet is adapted to dissipate such heat, such as by radiation. A plurality of closely-spaced heat pipes interior to the panel are thermally coupled to each other and to the inner facesheet for receiving heat from the equipment mounted thereon. A plurality of spaced-apart heat pipes interior to the panel are at about right angles to the closely-spaced heat pipes and are thermally coupled to the outer facesheet and to the closely-spaced heat pipes proximate their intersections therewith. Heat to be dissipated flows along short, direct and efficient paths from the equipment to the inner facesheet, to the closely-spaced heat pipes, to the spaced-apart heat pipes and to the outer facesheet from whence it is dissipated.

Abstract: The present invention relates to a hydrophone and to a virtual array of hydrophones for sensing the amplitude, frequency, and in arrays, the direction of sonic waves in water. The hydrophone employs a laser beam which is focused upon a small "focal" volume of water in which natural light scattering matter is suspended and which matter vibrates in synchronism with any sonic waves present. The vibration produces a phase modulation of the scattered light which may be recovered by optical heterodyne and sensitive phase detection techniques. The sonic waves are sensed at locations displaced from the focusing lenses. Because of this remote sensing capability, the physical hardware of an array of hydrophones may be confined to a small area comparable to the dimensions of the lenses themselves while the sensing of the sonic waves virtually occurs at widely spaced, remote focal volumes.

Abstract: Substrate material is molded directly to semiconductor chips and other electrical components that are positioned for integrated circuit module fabrication. Chips having contact pads are placed face down on a layer of adhesive supported by a base. A mold form is positioned around the chips. Substrate molding material is added within the mold form, and the substrate molding material is then hardened. A dielectric layer having vias aligned with predetermined ones of the contact pads and having an electrical conductor extending through the vias is situated on the hardened substrate molding material and the faces of the chips. A thermal plug may be affixed to the backside of a chip before substrate molding material is added. A connector frame may be placed on the adhesive layer before substrate molding material is added. A dielectric layer may be placed over the backsides of the chips before the substrate molding material is added to enhance repairability.

Abstract: A continuously variable hydrostatic transmission includes an input shaft connected to drive a hydraulic pump unit, a grounded hydraulic motor unit, and an output shaft. A wedge-shaped swashplate is pivotally mounted to the output shaft in driving connection to receive output torque resulting from the exchange of pressurized hydraulic fluid between the pump and motor units through specially configured ports in the swashplate. A hydraulically actuated ratio controller is pivotally linked to the swashplate to selectively adjust the swashplate angle relative to the output shaft axis and thereby change transmission ratio.

Abstract: A method for fabricating a multi-chip module substrate comprises providing a carrier having a well. Substrate molding material is poured into the carrier well. A plurality of chips is situated in the substrate molding material. A laminatable dielectric layer is laminated over the substrate molding material at a predetermined temperature and a predetermined pressure so that the substrate molding material flows and encapsulates the chips.

Abstract: A low power consumption amplifier that is essentially insensitive to the process used to fabricate the active devices of the amplifier employs feedback to minimize variations in electrical characteristics of the devices. For weight-sensitive microwave applications, a high electron mobility transistor (HEMT) or a pseudomorphic high electron mobility transistor (PHEMT) may be selected as an active device for each stage of the amplifier. HEMTs and PHEMTs typically exhibit greater device gain than do MESFETs, especially at the upper portion of X-band and above, so that a HEMT- or PHEMT-based stage of an amplifier where additional overall gain is required, can be achieved without significantly adversely affecting power consumption demands, and attendant electrical energy storage/generation requirements while achieving and/or maintaining an overall flat gain characteristic of the amplifier.

Abstract: A propellant composition comprising an admixture of a first hydrogen rich material and a second metal material which is capable of reacting exothermically with the first material. The ratio of the first material to the second material is selected such that the exothermic reaction forms a solid phase and a gas phase which contains substantial amounts of hydrogen. Preferably, the first hydrogen rich material comprises a material capable of providing nitrogen upon decomposition thereof, and the second metal material comprises a material capable of reacting exothermically with the nitrogen generated by the decomposition of the first material such that the solid phase comprises a solid nitride of the second metal material. In a preferred embodiment, the first material comprises ammonium azide, and the second material comprises boron, titanium, titanium hydride, or mixture thereof.

Abstract: To deploy an inflatable member, such as an occupant restraint safety bag in a motor vehicle, a buffer zone is pressurized by the firing of inflation initiator to release liquid propellant into the buffer zone through ruptured frangible seals in a stationary separator disk or in a movable piston for controlled ignition. The ignited liquid propellant generates a large volume of gas that is cooled and pressurize buffered prior to inflating introduction into the safety bag.