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Lightweight, Flexible Thermal Protection System for Fire Protection
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Wet Active Chevron Nozzle for Controllable Jet Noise Reduction
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IEEE 1394 Hub With Fault Containment

This innovation is designed to prevent a single end system communication node from negatively influencing the whole system’s behavior so that the network system can still operate if an end node is faulty. Placing a hub (star) in the middle of the system prevents propagation of critical control information that other end systems would react to, like block reset messages.

Posted in: Briefs, Electronics & Computers

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Ku Telemetry Modulator for Suborbital

A modulator utilizing the Ku-band instead of the usual S-band has been developed to improve transmission rates for suborbital platforms. The unit operates in the 14.5–15.5-GHz band and supports data rates up to 200 Mbps.

Posted in: Briefs, Electronics & Computers

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Radiometer on a Chip

Submillimeter-wave radiometers have traditionally been built by packaging each chip with a distinct function separately, and then combining the packaged chips to form subsystems. Instead of packaging one chip at a time, the radiometer on a chip (ROC) integrates whole wafers together to provide a robust, extremely powerful way of making submillimeter receivers that provide vertically integrated functionality. By integrating at the wafer level, customizing the interconnects, and planarizing the transmission media, it is possible to create a lightweight assembly performing the function of several pieces in a more conventional radiometer. This represents a greater than 50-fold decrease in both volume and mass. The act of combining the individual radiometer functions into a sequence of chips will also improve inter-component matching and reduce the loss associated with the power combining that accompanies today’s radiometers.

Posted in: Briefs, Electronics & Computers

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Measuring Luminescence Lifetime With Help of a DSP

An instrument for measuring the lifetime of luminescence (fluorescence or phosphorescence) includes a digital signal processor (DSP) as the primary means of control, generation of excitation signals, and analysis of response signals. In contrast, prior luminescencelifetime- measuring instruments have utilized primarily analog circuitry to perform these functions. Such instruments are typically used as optical chemical sensors.

Posted in: Briefs, Electronics & Computers

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Bonded Invar Clip Removal Using Foil Heaters

A new process uses local heating and temperature monitoring to soften the adhesive under Invar clips enough that they can be removed without damaging the composite underneath or other nearby bonds. Two 1×1 in. (≈2.5×2.5 cm), 10-W/in.2 (≈1.6-W/cm2), 80-ohm resistive foil Kapton foil heaters, with pressure-sensitive acrylic adhesive backing, are wired in parallel to a 50-V, 1-A limited power supply. At 1 A, 40 W are applied to the heater pair. The temperature is monitored in the clip radius and inside the tube, using a dual thermocouple readout. Several layers of aluminum foil are used to speed the heat up, allowing clips to be removed in less than five minutes. The very local heating via the foil heaters allows good access for clip removal and protects all underlying and adjacent materials.

Posted in: Briefs, Manufacturing & Prototyping

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Gratings Fabricated on Flat Surfaces and Reproduced on Non-Flat Substrates

A method has been developed for fabricating gratings on flat substrates, and then reproducing the groove pattern on a curved (concave or convex) substrate and a corresponding grating device. First, surface relief diffraction grating grooves are formed on flat substrates. For example, they may be fabricated using photolithography and reactive ion etching, maskless lithography, holography, or mechanical ruling. Then, an imprint of the grating is made on a deformable substrate, such as plastic, polymer, or other materials using thermoforming, hot or cold embossing, or other methods. Interim stamps using electroforming, or other methods, may be produced for the imprinting process or if the same polarity of the grating image is required. The imprinted, deformable substrate is then attached to a curved, rigid substrate using epoxy or other suitable adhesives. The imprinted surface is facing away from the curved rigid substrate.

Posted in: Briefs, TSP, Manufacturing & Prototyping

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Fabricating Radial Groove Gratings Using Projection Photolithography

Projection photolithography has been used as a fabrication method for radial grove gratings. Use of photolithographic method for diffraction grating fabrication represents the most significant breakthrough in grating technology in the last 60 years, since the introduction of holographic written gratings. Unlike traditional methods utilized for grating fabrication, this method has the advantage of producing complex diffractive groove contours that can be designed at pixel-by-pixel level, with pixel size currently at the level of 45×45 nm. Typical placement accuracy of the grating pixels is 10 nm over 30 nm. It is far superior to holographic, mechanically ruled or direct e-beam written gratings and results in high spatial coherence and low spectral cross-talk. Due to the smooth surface produced by reactive ion etch, such gratings have a low level of randomly scattered light. Also, due to high fidelity and good surface roughness, this method is ideally suited for fabrication of radial groove gratings.

Posted in: Briefs, Manufacturing & Prototyping

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