Abstract: A modulator or demodulator has a transparent nonlinear dielectric material (crystal), and an optical fiber for coupling light thereinto. RF is coupled into the crystal by a dielectric waveguide which is matched to the crystal. The nonlinear crystal causes the light and RF to interact, to cause products which can be detected at the dielectric waveguide. When used as a modulator or demodulator, the modulated light may be coupled out by a second optical fiber, and or the modulated RF may be coupled out by a second dielectric waveguide. The dielectric waveguide may be transitioned to conventional hollow conductive waveguide.

Abstract: A dye laser having a changeable output frequency includes a system for storing, selecting and introducing a dye into a liquid lasing medium. Dyes are contained in individual glass ampules arranged on a wheel stored in the fluid reservoir. A stepper motor rotates the wheel to select an ampule and a striker solenoid breaks the ampule open to release the dye into solution. A scrubber system removes dye from the liquid to allow the dye to be changed.

Abstract: An optical correlator uses ferroelectric liquid crystal spatial light modulators (FLC-SLM's) in both the reference and filter planes. The SLM's include an electrically addressable memory to store images in the form a two-dimensional array of reflective pixels beneath the FLC layer. The SLM's selectively rotate the polarization of the light reflected by each pixel in accordance with the stored image. In particular, a laser produces a polarized beam that is directed through a first polarizing beamsplitter and onto the reference SLM. This beamsplitter blocks unmodulated light reflected by the reference SLM and transmits modulated light through a set of Fourier tranform lenses. The resulting beam is directed through a second polarizing beam splitter onto a filter SLM that has been programmed with the complex conjugate of the Fourier transform of a desired target image.

Abstract: An amine reacted acrylated epoxy resin blend that is particularly suitable for impregnating a fiber material and at least initial curing by exposure to ionizing radiation. These epoxy resins are basically produced by combining epoxy resins, including esterified epoxy resins, with stoichiometric quantities of aliphatic or cyclo aliphatic polyamines. The resins can be used to impregnate fibers which are exposed to ionizing radiation such as an electron beam or ultraviolet light and immediately formed into a structure, such as by filament winding. A short exposure to the ionizing radiation produces a stress-free, self supporting structure that can be fully cured through simple heating without elaborate tooling, vacuum bagging, autoclaves or the like.

Abstract: A power supply for a thruster for space applications (e.g., an arcjet thruster) comprises a series/parallel resonant converter wherein the load quality (Q) factor of the resonant tank circuit inherently varies with arc voltage so as to accommodate changes in arc voltage from initiation thereof through steady-state operation. Effectively, the resonant tank circuit acts as a ballast by matching the arc during initiation thereof through steady-state operation. Furthermore, the resonant converter operates in a soft-switching, low-voltage switched mode so as to maximize efficiency.

Abstract: An analog built-in-test system has a processor for controlling two identical cells, each of which has its own control means for autonomous operation. Each cell may simultaneously receive and generate analog signals from/to external nodes to be tested/stimulated. For these functions, each cell contains analog to digital (A/D) and digital to analog (D/A) converters, timers which control the sampling/conversion rate of the A/D and D/A converters, and A/D and D/A memory means, each for storing the digitized samples. Each cell further has an additional timer for measuring time periods between programmable triggers. Besides being coupled to the processor, each cell is coupled to the other by means of a cell-to-cell bus which conveys data and control signals from one cell to the other. The architecture including the cell-to-cell bus permits the two cells to coordinate with one another to perform measurements such as the phase difference between two analog signals.

Abstract: A multi-pole magnetic component, such as an inductor, includes z-folded conductive film windings and a core having a plurality of pairs of spaced apart core posts extending between a base plate and a top plate of the core. The core includes an air gap that is distributed substantially evenly along the flux path. Magnetic flux flows through the core posts in a series manner so as to have an opposite flux direction in adjacent poles. Preferably, the air gap is determined such that the ratio of the distance between each adjacent core post and the distance between the base and top plates results in magnetic fields that are substantially tangential to the surface of the conductive film winding. Furthermore, the core posts are preferably shaped to have a larger cross sectional area at the base portion of the posts than at the top portion thereof. Alternatively, the core posts are attached to the bottom plate and are inserted into suitably shaped cut-out portions of the top plate.

Abstract: The invention relates to a self monitoring/calibrating phased array radar in which the operating path for transmission and the operating path for reception may be monitored/calibrated by the addition of a corporate calibration network coupled at the plural end to the antenna elements and at the singular end to the exciter/receiver, and switching means to selectively route the monitoring/calibrating signal derived from the exciter in a transmit path to calibration path sequence or in a calibration path to receive path sequence.In one embodiment of the invention, a phase shifter common to transmit and receive paths is adjustable in increments under active logical control for calibration, while power and gain performance is monitored but not actively controlled. A novel T/R sub-assembly houses the operating electronics for four antenna elements in the form of four T/R modules with a one to four divider network in the transmit/receive path and in the calibration path.

Abstract: A lift vehicle has an elongated support structure affixed to its upper end, with the axis of elongation of the support structure parallel to or coincident with the longitudinal axis of the lift vehicle. The support structure defines a plurality of attachment planes, each of which includes the axis of elongation, which together divide the region about the axis of elongation into N angular sections or regions, each with an included angle of 360.degree./N. A plurality MN of spacecraft are organized into a plurality of M sets or layers, each containing N spacecraft. Each spacecraft defines first and second lateral support planes, skewed relative to each other, which intersect at a line of intersection, is parallel to the axis of elongation when the spacecraft are mounted to the support structure. Two or more spacecraft are mounted in end-to-end position in each angular portion. Each spacecraft stiffens the support structure, so that the stiffened support structure, can sustain the launch forces.

Abstract: The invention relates to an air bridge and an evaporative process for making air bridges. A first layer of photoresist is patterned to create two openings over the contacts to be connected, separated by a strip of photoresist. The photoresist strip is hard baked to allow it to soften and to cause further cross linking. The softening allows surface tension to reshape the photoresist strip to create a gradually sloping arcuate surface between contact openings upon which a metal layer of nearly constant thickness may be evaporated. A second layer of photoresist is then applied, and patterned to create a single large opening embracing both contacts and the now arcuate hard baked photoresist strip. An arch within the large opening connecting both contacts is formed by evaporation. Excess metal and both photoresist layers are then removed, leaving a novel, arch shaped air bridge.

Abstract: The electrical operating characteristics of a microwave circuit are modified by providing a dielectric layer on the circuit in a pattern which modifies the electrical characteristics of an overlay responsive portion of the circuit in a manner which results in the overall circuit having a desired electrical operating characteristic within a tolerance. Adjustment of the operating characteristics may be done in an iterative manner of measuring the characteristics, modifying the distribution of dielectric material and remeasuring the operating characteristics until satisfactory operating characteristics are obtained.

Abstract: An elevation mechanism, for changing the elevation angle of an attachable container subassembly, has an outer housing having an integral portion for mounting the container subassembly, and an inner housing having an exterior surface about which the outer housing is rotatably supported. A motor within the inner housing supplies torque to a gear train, which includes a planetary gear system for rotating the outer housing and the container subassembly attachable thereto, with respect to the inner housing. The inner housing can be fastened to a surface, generally in the vertical plane, with respect to which surface the rotating outer housing moves the container subassembly in adjustable elevation disposition.

Abstract: A method for producing advanced composite structures includes the assembly of a number of layers of fibrous reinforcements into a desired configuration. A vacuum is applied to the reinforcement in order to evacuate any air therefrom and to consolidate the plurality of fibrous reinforcements. Resin is introduced to the reinforcement by using a flow path therethrough having entry and exit points. The vacuum is used to transmit the resin through the reinforcement between the entry and exit points. The resin flows into the reinforcement due to the pressure differential between the evacuated reinforcement and the hydrostatic pressure on the resin as well as the capillary effect on the reinforcement.

Abstract: In a method for preserving an air bridge structure on an integrated circuit chip used in an overlay process, a patternable protective layer is applied for providing mechanical strength to prevent deformation during subsequent processing. A polymeric film layer is applied over the chip and protective layer, and interconnections are fabricated through the polymeric film layer. The polymeric film layer is removed from the area over the air bridge structure. The patternable protective layer is then removed, leaving the resultant structure with an undamaged air bridge which is free of residue.

Abstract: A thermal control surface for a spacecraft includes flexible OSR tiles (310) 0.0015 inches thick. Each tile includes a transparent substrate (312) with a reflective second surface (314), such as a coating of silver. The front or space-facing side is coated with a transparent, electrically conductive layer (316) of indium oxide (IO) or indium-tin oxide (ITO), which laps over the edges of the OSR tile, and is in electrical contact with the reflective coating.The IO or ITO coating, or a separate electrically conductive coating (610) such as nichrome, forms a protective coating for the reflective surface, and maintains contact with the front surface of the tile. The IO or ITO layer (316) in conjunction with the back side coating provides front-to-back electrical conduction. The OSR is mounted to an electrically conductive surface (110) of the spacecraft, such as an aluminum or graphite-fiber-reinforced epoxy resin, by a sheet of transfer adhesive (410).

Abstract: In a monopulse radar processor, the usual sum (s) and difference (d) signals are manipulated to produce two other signals (s+ad and s+bd, in which a and b are constants). The phase of each of these derived signals with respect to the sum signal is then determined. The real part of d/s and, if desired, the imaginary part of d/s are calculated from these measured phase angles. The real part of d/s is the conventional output from a monopulse processor.

Abstract: An absorptive/transmissive structure is disclosed which can be used to fabricate antenna radomes to thereby reduce the electromagnetic signature of the radome and antenna without disrupting the electromagnetic waves generated by the antenna. An artificial dielectric material is placed on a frequency selective surface to absorb the energy of electromagnetic waves at a particular frequency or range of frequencies.

Abstract: An optical signal processing system includes a number of optical time delay units to generate differentially time-delayed optical signals. Each optical time delay unit includes at least an in put polarizing beam splitter (PBS) system having an input system Thompson prism and an output PBS system including an output Thompson prism. Each Thompson prism has a high extinction ratio and is positioned to act as a polarizing beam splitter, providing a high signal to noise ratio optical signal processing system. Selectively polarized light beams are deflected by the polarizing beam splitters onto predetermined paths that cause the respective light beams to be differentially time delayed dependent on the path that they follow through the optical signal processing system.

Abstract: A communications system (FIG. 7) couples together a number of entities or communications devices 710 by means of alternating stages (722, 726) of crossbar switches (712, 716) and stages (724, 728) of stride extender coupler circuits, which are preferably in the form of modules (714, 718), together with a final stage (730) of cross-connecting "termination" circuits or modules (720). The system can be expanded in performance capability (FIG. 8) by adding further stages (822, 828) of crossbar switches and stride extender coupling circuits or modules.

Abstract: A spacecraft uses monopropellant arcjets for velocity change such as for north-south stationkeeping. It has been discovered that, while an arcjet cannot be modulated by pulsing the fuel supply, the amount of thrust can be varied by modulating the power applied to the arc, without extinguishing the arc. While the specific impulse (I.sub.SP) of the arcjet is thereby reduced from the maximum I.sub.SP of which the arcjet is capable, the resulting I.sub.SP may still be larger than the combined I.sub.SP of an unmodulated arcjet in conjunction with a modulated chemical thruster in a typical scenario. According to the invention, attitude control is provided in conjunction with north-south stationkeeping or other velocity change by, in response to an error signal generated by an attitude control system, modulating the arc power(s) of an arcjet thruster(s), which provides the velocity change. The arc is not extinguished during the stationkeeping maneuver, but is varied in magnitude.