Electrical, Electronics, and Avionics

Antennas

Stories

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Briefs: Electronics & Computers
Patch Antenna Fed via Unequal-Crossed-Arm Aperture
A proposed rectangular-patch antenna for transmitting or receiving microwave circularly polarized (CP) radiation would be fed via a cross-shaped aperture that would have unequal arms and would, in turn, be fed at a single point via a microstrip transmission line. As a consequence of the unequal-arm...
Briefs: RF & Microwave Electronics
A horn antenna (see Figure 1) has been developed to satisfy requirements specific to its use as an essential component of a high-efficiency Ka-band amplifier: The combination of the horn antenna and an...
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Briefs: Electronics & Computers
A method of maintaining radio communication despite the emergence of unpredictable fades and nulls in the radiation pattern of an antenna has been proposed. The method was originally...
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Briefs: Electronics & Computers
A class of reconfigurable microwave antennas now undergoing development comprise fairly conventional printed-circuit feed elements and radiating patches integrated with novel switches...
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Briefs: Manufacturing & Prototyping
Fabrication of Spherical Reflectors in Outer Space
A process is proposed for fabrication of lightweight spherical reflectors in outer space for telescopes, radio antennas, and light collectors that would be operated there. The process would obviate the relatively massive substrates and frames needed to support such reflectors in normal Earth...
Briefs: Physical Sciences
An experimental airborne remote sensing system includes a remotely controlled, lightweight, solar-powered airplane (see figure) that carries two digital-output electronic cameras and communicates...
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Briefs: Electronics & Computers
CHEM-Based Self-Deploying Spacecraft Radar Antennas
A document proposes self-deploying spacecraft radar antennas based on cold hibernated elastic memory (CHEM) structures. Described in a number of prior NASA Tech Briefs articles, the CHEM concept is one of utilizing open-cell shape-memory-polymer (SMP) foams to make lightweight structures that can...
Briefs: RF & Microwave Electronics
An improved suspended-patch antenna has been designed to operate at a frequency of about 23 GHz with linear polarization and to be one of four identical antennas in a rectangular array. The...
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Briefs: Photonics/Optics
Tunable optical true-time delay devices that would exploit electromagnetically induced transparency (EIT) have been proposed. Relative to prior true-time delay devices (for example,...
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Briefs: Test & Measurement
An apparatus and technique have been devised for measuring the radiation pattern of a microwave patch antenna that is one of a number of identical units that have been...
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Briefs: Physical Sciences
A proposed technique for locating concealed objects (especially small antipersonnel land mines) involves the acquisition and processing of spectral signatures over broad microwave...
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Briefs: Physical Sciences
An improved method of calibrating a large directional radio antenna of the type used in deep-space communication and radio astronomy has been developed. This method involves a...
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Briefs: Electronics & Computers
Lightweight, deployable antennas for a variety of outer-space and terrestrial applications would be designed and fabricated according to the concept of cold hibernated elastic memory (CHEM)...
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Briefs: Electronics & Computers
Microstrip-patch-style antennas that generate monopole radiation patterns similar to those of quarter-wave whip antennas can be designed to have dimensions smaller than those needed...
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Briefs: Communications
Orbiter Interface Unit and Early Communication System
A report describes the Orbiter Interface Unit (OIU) and the Early Communication System (ECOMM), which are systems of electronic hardware and software that serve as the primary communication links for the International Space Station (ISS). When a space shuttle is at or near the ISS during...
Briefs: Test & Measurement
An apparatus for measuring the rate of flow and the mass density of a liquid or slurry includes a special section of pipe instrumented with microwave and sonic sensors, and a computer...
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Briefs: Electronics & Computers
Radar for Monitoring Hurricanes From Geostationary Orbit
A document describes a scanning Doppler radar system to be placed in a geostationary orbit for monitoring the three-dimensional structures of hurricanes, cyclones, and severe storms in general. The system would operate at a frequency of 35 GHz. It would include a large deployable spherical...
Briefs: Photonics/Optics
A compact, dual-frequency, dual-polarization, wide-angle-scanning antenna system has been developed as part of an airborne instrument for measuring rainfall. This system is an upgraded...
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Briefs: Electronics & Computers
Efforts are under way to apply the concept of evolvable hardware (EHW) to compensate for variations, with temperature, in the operational characteristics of electronic circuits. To...
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Briefs: Information Technology
Finding Minimum-Power Broadcast Trees for Wireless Networks
Some algorithms have been devised for use in a method of constructing tree graphs that represent connections among the nodes of a wireless ommunication network. These algorithms provide for determining the viability of any given candidate connection tree and for generating an initial set...
Briefs: Software
Readout of DSN Monitor Data
DSN Monitor Data Reader is a computer program that, as its name suggests, reads file of monitor data from the Deep Space Network (DSN). The monitor data constitute information on the status and performance of tracking, telemetry, command, and pointing equipment at the DSN antennas. The DSN has recently introduced a new,...
Briefs: Electronics & Computers
A two-frequency, polarimetric, spaceborne synthetic-aperture radar (SAR) system has been proposed for measuring the moisture content of soil as a function of depth, even in the presence of...
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Briefs: Electronics & Computers
A modular wireless data-acquisition and control system, now in operation at Kennedy Space Center, offers high performance at relatively low cost. The system includes a central station and a...
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Briefs: Electronics & Computers
Directional Radio-Frequency Identification Tag Reader
A directional radio-frequency identification (RFID) tag reader has been designed to facilitate finding a specific object among many objects in a crowded room. The device could be an adjunct to an electronic inventory system that tracks RFID-tagged objects as they move through reader-equipped...
Briefs: Electronics & Computers
A finned-ladder structure has been invented in an effort to improve the design of the slow-wave circuit of a traveling-wave tube (TWT). The point of departure for the design effort was a prototype TWT...
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Briefs: Mechanical & Fluid Systems
Self-Inflatable/Self-Rigidizable Reflectarray Antenna
A report describes recent progress in a continuing effort to develop large reflectarray antennas to be deployed in space. Major underlying concepts were reported in two prior NASA Tech Briefs articles: "Inflatable Reflectarray Antennas" (NPO-20433), Vol. 23, No. 10 (October 1999), page 50 and...
Briefs: Electronics & Computers
The combination of a de-embedding technique and a direct on-substrate measurement technique has been devised to enable measurement of the electrical characteristics (impedances,...
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Briefs: Electronics & Computers
A proposed design for a phased array fed cylindrical reflector microwave antenna would enable enhancement of the radiation pattern through partially adaptive amplitude and phase control...
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Briefs: Information Technology
Software for Allocating Resources in the Deep Space Network
TIGRAS 2.0 is a computer program designed to satisfy a need for improved means for analyzing the tracking demands of interplanetary space-flight missions upon the set of ground antenna resources of the Deep Space Network (DSN) and for allocating those resources. Written in Microsoft Visual...

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