Tech Briefs

Microstrip Antenna Arrays on Multilayer LCP Substrates

Antennas, feedlines, and switches are embedded in and on flexible sheets. A research and development effort now underway is directed toward satisfying requirements for a new type of relatively inexpensive, lightweight, microwave antenna array and associated circuitry packaged in a thin, flexible sheet that can readily be mounted on a curved or flat rigid or semi-rigid surface. A representative package of this type consists of microwave antenna circuitry embedded in and/or on a multilayer liquid- crystal polymer (LCP) substrate. The circuitry typically includes an array of printed metal microstrip patch antenna elements and their feedlines on one or more of the LCP layer(s). The circuitry can also include such components as electrostatically actuated microelectromechanical systems (MEMS) switches for connecting and disconnecting antenna elements and feedlines. In addition, the circuitry can include switchable phase shifters described below.

Posted in: Briefs, TSP, Semiconductors & ICs, Antennas, Microelectromechanical devices, Research and development, Polymers

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Multiple-Agent Air/Ground Autonomous Exploration Systems

These systems would cover large areas and would function robustly. Autonomous systems of multipleagent air/ground robotic units for exploration of the surfaces of remote planets are undergoing development. Modified versions of these systems could be used on Earth to perform tasks in environments dangerous or inaccessible to humans: examples of tasks could include scientific exploration of remote regions of Antarctica, removal of land mines, cleanup of hazardous chemicals, and military reconnaissance.

Posted in: Briefs, TSP, Electronics & Computers, Product development, Robotics, Autonomous vehicles

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Multiloop Rapid-Rise/Rapid Fall High-Voltage Power Supply

A proposed multiloop power supply would generate a potential as high as 1.25 kV with rise and fall times <100 μs. This power supply would, moreover, be programmable to generate output potentials from 20 to 1,250 V and would be capable of supplying a current of at least 300 μA at 1,250 V. This power supply is intended to be a means of electronic shuttering of a microchannel plate that would be used to intensify the output of a charge-coupled-device imager to obtain exposure times as short as 1 ms. The basic design of this power supply could also be adapted to other applications in which high voltages and high slew rates are needed. At the time of reporting the information for this article, there was no commercially available power supply capable of satisfying the stated combination of voltage, rise-time, and fall-time requirements.

Posted in: Briefs, Electronics & Computers, High voltage systems

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Applications for Subvocal Speech

research and development effort now underway is directed toward the use of subvocal speech for communication in settings in which (1) acoustic noise could interfere excessively with ordinary vocal communication and/or (2) acoustic silence or secrecy of communication is required. By “subvocal speech” is meant sub-audible electromyographic (EMG) signals, associated with speech, that are acquired from the surface of the larynx and lingual areas of the throat. Topics addressed in this effort include recognition of the sub-vocal EMG signals that represent specific original words or phrases; transformation (including encoding and/or enciphering) of the signals into forms that are less vulnerable to distortion, degradation, and/or interception; and reconstruction of the original words or phrases at the receiving end of a communication link. Potential applications include ordinary verbal communications among hazardous- material-cleanup workers in protective suits, workers in noisy environments, divers, and firefighters, and secret communications among law enforcement officers and military personnel in combat and other confrontational situations.

Posted in: Briefs, Electronics & Computers, Acoustics

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A 640 x 512-Pixel Portable Long-Wavelength Infrared Camera

This hand-held camera shows promise for imaging at high thermal resolution.A portable long-wavelength infrared electronic camera having a cutoff wavelength of 9 μm has been built around an image sensor in the form of a 640 × 512- pixel array of AlxGa1–xAs/GaAs quantum well infrared photodetectors (QWIPs). This camera is an intermediate product of a continuing program to develop high-resolution, high-sensitivity infrared cameras.

Posted in: Briefs, TSP, Electronics & Computers, Imaging and visualization

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An Array of Optical Receivers for Deep-Space Communications

This array would be considerably simpler and less expensive to implement. An array of small optical receivers is proposed as an alternative to a single large optical receiver for high-data-rate communications in NASA’s Deep Space Network (DSN). Because the telescope for a single receiver capable of satisfying DSN requirements must be greater than 10 m in diameter, the design, building, and testing of the telescope would be very difficult and expensive. The proposed array would utilize commercially available telescopes of 1- m or smaller diameter and, therefore, could be developed and verified with considerably less difficulty and expense.

Posted in: Briefs, TSP, Electronics & Computers, Optics, Test equipment and instrumentation

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Composite Elastic Skins for Shape-Changing Structures

Anisotropic stiffness properties can be tailored for specific applications. Composite elastic skins having tailorable mechanical properties have been invented for covering shape-changing (“morphable”) structures. These skins are intended especially for use on advanced aircraft that change shapes in order to assume different aerodynamic properties.

Posted in: Briefs, TSP, Materials, Composite materials, Elastomers, Aircraft

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