A triangular phased array excited by oscillators coupled on a hexangonal lattice
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triangular phased array oscillators lattice↗
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Results for “Phased array”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Efficient structures for geosynchronous spacecraft solar arrays, phase 4
Efficient structures for geosynchronous spacecraft solar arrays were investigated. The STACBEAM (stacking triangular articulated compact beam) concept was selected. The primary component, the solar array blanket, is stored in a folded configuration and is deployed by controlled linear extension. Blanket stiffness is attained by axially tensioning the blanket and by providing periodic lateral ribs and standoffs which attach the blanket to the beam at several places along its length. The STACBEAM deploys sequentially (one bay at a time) using a deployer of sufficient rigidity so that beam stiffness is not degraded during deployment. The beam does not rotate during deployment, thus making blanket beam attachment possible in the packaged condition. In addition to high bending stiffness, the STACBEAM possesses high torsional rigidity due to nonflexible diagonals. The concept is adaptable to various size and loading requirements by changing member diameter and baylength, thus affecting the ratio of packaged and deployed length.
Adams, L. R.↗
The Implications of Encoder/Modulator/ Phased Array Designs for Future Broadband LEO Communications
In this paper we summarize the effects of modulation and channel coding on the design of wide angle scan, broadband, phased army antennas. In the paper we perform several trade studies. First, we investigate the amplifier back-off requirement as a function of variability of modulation envelope. Specifically, we contrast constant and non-constant envelope modulations, as well as single and multiple carrier schemes. Additionally, we address the issues an(f concerns of using pulse shaping filters with the above modulation types. Second, we quantify the effects of beam steering on the quality of data, recovery using selected modulation techniques. In particular, we show that the frequency response of the array introduces intersymbol interference for broadband signals and that the mode of operation for the beam steering controller may introduce additional burst or random errors. Finally, we show that the encoder/modulator design must be performed in conjunction with the phased array antenna design.
Vanderaar, Mark↗
Analysis of L/X-Band Phased Array Fed Cylindrical Reflector with Super-Quadric Projected Aperture for Cold Regions/Soil Moisture Mission
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Moisture Cold regions↗
Trends in development of broad-band phased arrays in commercial satellite systems and the potential applications for tracking high Earth orbit satellites, deep space vehicles, and mobile robotic netw
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phased arrays mobile robotic deep space satellite↗
Towards Gbps Downlinks from Low-Cost Active Phased Arrays
Spacecraft performing science missions use high-directivity antennas to quickly downlink large amounts of collected data. Movement required to keep gimbaled reflector antennas trained on target receivers can impart blockages or vibrations which perturb precision science instruments. Recent manufacturing advances have made Ka-band electronically-steered antenna arrays a cost-effective option to mitigate these challenges, but only if these devices can be proven to deliver comparable quality of service. In this work we present a hardware and software architecture for high-rate links using an active phased array-based terminal in a 1U (10cm cube) form factor. Over-the-air tests in an antenna range characterize two key features of the architecture: high-order (32APSK and above) modulations and dual carriers. We calculate an optimal modulation-dependent input power backoff from array saturation and perform orbital simulations of the link at this operating point. We conclude that reliable links with rates in excess of 1Gbps are possible with current-generation hardware.
Adam Gannon↗
A review of recent developments in the application of coupled oscillators to phased array antennas
Some years ago it was proposed that an array of electronic oscillators coupled to nearest neighbors can be made to mutually injection lock and oscillate as an ensemble thus implementing spatial power combining.
coupled oscillators injection locking phased array↗
The UAVSAR phased array aperture
This paper describes the development of a patch antenna array for an L-band repeat-pass interferometric synthetic aperture radar instrument that is to be flown on an unmanned aerial vehicle.
antenna tile↗
Prospects for tracking spacecrafts within 2 million Km of Earth with phased array antennas
Recent advances in space technology for Earth observations, global communications, and positioning systems have created heavy traffic at a variety of orbits. These include smart sensors in low Earth orbits (LEO), internet satellites in LEO and GEO orbits, Earth observing satellites in high Earth orbits (HEO), observatory class satellites at Lagrangian libration points, and those heading for deep space.
tracking phased array GEO HEO Lagrange deep space ↗
On the Scan Performance of Phased Array Fed Cylindrical Reflector with SuperQuadric Projected Aperture: PO/FFT Analysis
The need for enhanced observational capabilities in a spaceborne microwave radar instrument to measure rainfall rates, vertical velocities with precipitation, and latent-heating profiles accurately and at sufficiently good resolution and spatial coverage throughout the tropics and mid-latitudes requires a large antenna with high-performance beam-scanning capabilities to avoid contamination by the surface clutter known as range ambiguity.
Scan↗
Large area solar array, phase 2 Final report
Design and fabrication of large area solar cell array capable of producing 50 kW of power for interplanetary spacecraft flights
Apperson, J. L.↗
Antenna-array, phase quadrature tracking system
Phase relationship between input signals appearing on widely-spaced parallel connected antenna elements in array is automatically adjusted in phase quadrature tracking system. Compact and lightweight design permit use in wide variety of airborne communications networks.
Cubley, H. D.↗
Design and fabrication of a high temperature leading edge heating array, phase 1
Progress during a Phase 1 program to design a high temperature heating array is reported for environmentally testing full-scale shuttle leading edges (30 inch span, 6 to 15 inch radius) at flight heating rates and pressures. Heat transfer analyses of the heating array, individual modules, and the shuttle leading edge were performed, which influenced the array design, and the design, fabrication, and testing of a prototype heater module.
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Thermal infrared array, phase 1. Volume 1: Technical
The recommended design configuration for the focal plane array of a 1,000 element linear pushbroom system consists of 32 modules; the complete configuration is built by butting together two 1024 linear arrays. Each of the linear arrays is formed by edge butting 16 modules together. By staggering the modules of the two rows, the channel outages which occur where the modules are edge butted can be eliminated. Two stages TDI operation is performed by the post processing electronics, which reduces the design complexity of the focal plane. Systems studies show that: (1) a single focal plane design can satisfy both the LEO and SEOS mission configurations; (2) available optical designs can meet mission goals; (3) MTF can be traded with optical complexity in a future study; (4) a chopping mechanism can be devised to modifying modulate radiation to a 4-inch focal plane as well as insert two calibration sources at the required frequencies for chopping and calibration; (5) radiative cooling technology should be suitable for a future sensor in either mission configuration; and (6) cold shielding is not a requirement.
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Optical Phased Array Using Guided Resonance with Backside Reflectors
Methods and systems for controlling the phase of electromagnetic waves are disclosed. A device can consist of a guided resonance grating layer, a spacer, and a reflector. A plurality of devices, arranged in a grid pattern, can control the phase of reflected electromagnetic phase, through refractive index control. Carrier injection, temperature control, and optical beams can be applied to control the refractive index.
Horie, Yu↗
Optical Phased Array Using Guided Resonance with Backside Reflectors
Methods and systems for controlling the phase of electromagnetic waves are disclosed. A device can consist of a guided resonance grating layer, a spacer, and a reflector. A plurality of devices, arranged in a grid pattern, can control the phase of reflected electromagnetic phase, through refractive index control. Carrier injection, temperature control, and optical beams can be applied to control the refractive index.
Horie, Yu↗
Optoelectronic Control Of Phased-Array Antenna
Radiation patterns switched within microseconds. According to concept, digital beam-steering information destined for number of phased antenna elements transmitted in serial multiplex along optical fiber to optoelectronic integrated circuit (OEIC), demultiplexing information into parallel electronic channels to phase shifters associated with various elements. Because of small distances between elements of such arrays, compactness of optical fibers makes them attractive for distribution of beam-steering (phase-shifting) control signals. Also offers advantages of light weight, low attenuation, mechanical flexibility, large bandwidth, and immunity to both crosstalk and electromagnetic interference.
Bhasin, K. B.↗