A review of recent developments in the applications of coupled oscillators to phased array antennas
Explore the source record for details and available documents.
coupled oscillators injection locking phased array↗
SEARCH · Search NASA
Results for “phased array antenna”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
MSAT mobile electronically steered phased array antenna development
The Mobile Satellite Experiment (MSAT-X) breadboard antenna design demonstrates the feasibility of using a phased array in a mobile satellite application. An electronically steerable phased array capable of tracking geosynchronous satellites from anywhere in the Continental United States has been developed. The design is reviewed along with the test data. Cost analysis are presented which indicate that this design can be produced at a cost of $1620 per antenna.
Schmidt, Fred↗
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.↗
Control of small phased-array antennas
Series of reports, patent descriptions, calculator programs, and other literature describes antenna control and steering apparatus for seven-element phased array. Though series contains information specific to particular system, it illustrates methods that can be applied to antennas with greater or fewer numbers of elements. Included are programs for calculating beam parameters and design functions and information to interfacing digital controller to beam-steering apparatus.
Doland, G. D.↗
System Noise Analysis for Phased-Array Antennas
Explore the source record for details and available documents.
Photonic phased-array↗
Electro-optical processing of phased-array antenna data
An on-line two-dimensional optical processor has been used to process simulated linear and planar phased-array radar data off-line but at real-time data rates. The input transducer is an electron-beam-addressed KD2PO4 light valve.
Casasent, D.↗
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.↗
Antenna array phase quadrature tracking system Patent
Development of electronic circuit for combining input signals on two separate antennas to form two processed signals
Cubley, H. D.↗
Coaxial phased array antenna
A coaxial antenna array for communicating circularly polarized electromagnetic radiation is disclosed. A pair of open ended antenna cavities is coaxially constructed and operates by excitation of linear radiation elements arranged within each of the cavities. A pair of crossed dipole radiation devices is centered within the inner cavity and operated by means of a phase shifting network circuit to transmit as well as receive circularly polarized radiation. Four monopole radiation devices are symmetrically arranged to operate in the outer cavity in phase quadrature by means of the phase shifting network circuit to both transmit and receive circularly polarized electromagnetic radiation. Combined operation of the two antenna cavities with a 180 deg phase differential between the fields related to the two antenna cavities provides a broad beam, relatively wide frequency bandwidth communication capability. Particular embodiments disclosed feature a generally square cavity array as well as a circular cavity array.
Ellis, H., Jr.↗
Multibeam Phased Array Antennas
In this study, a new architecture for Ka-band multi-beam arrays was developed and demonstrated experimentally. The goal of the investigation was to demonstrate a new architecture that has the potential of reducing the cost as compared to standard expensive phased array technology. The goals of this specific part of the project, as stated in the yearly statement of work in the original proposal are: 1. Investigate bounds on performance of multi-beam lens arrays in terms of beamwidths, volume (size), isolation between beams, number of simultaneous beams, etc. 2. Design a small-scale array to demonstrate the principle. The array will be designed for operation around 3OGHz (Ka-band), with two 10-degree beamwidth beams. 3. Investigate most appropriate way to accomplish fine-tuning of the beam pointing within 5 degrees around the main beam pointing angle.
Popovic, Zoya↗
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 ↗
Optimizing Satellite Communications With Adaptive and Phased Array Antennas
A new adaptive antenna array architecture for low-earth-orbiting satellite ground stations is being investigated. These ground stations are intended to have no moving parts and could potentially be operated in populated areas, where terrestrial interference is likely. The architecture includes multiple, moderately directive phased arrays. The phased arrays, each steered in the approximate direction of the satellite, are adaptively combined to enhance the Signal-to-Noise and Interference-Ratio (SNIR) of the desired satellite. The size of each phased array is to be traded-off with the number of phased arrays, to optimize cost, while meeting a bit-error-rate threshold. Also, two phased array architectures are being prototyped: a spacefed lens array and a reflect-array. If two co-channel satellites are in the field of view of the phased arrays, then multi-user detection techniques may enable simultaneous demodulation of the satellite signals, also known as Space Division Multiple Access (SDMA). We report on Phase I of the project, in which fixed directional elements are adaptively combined in a prototype to demodulate the S-band downlink of the EO-1 satellite, which is part of the New Millennium Program at NASA.
Ingram, Mary Ann↗
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↗
Optically controlled phased array antenna concepts using GaAs monolithic microwave integrated circuits
The desire for rapid beam reconfigurability and steering has led to the exploration of new techniques. Optical techniques have been suggested as potential candidates for implementing these needs. Candidates generally fall into one of two areas: those using fiber optic Beam Forming Networks (BFNs) and those using optically processed BFNs. Both techniques utilize GaAs Monolithic Microwave Integrated Circuits (MMICs) in the BFN, but the role of the MMIC for providing phase and amplitude variations is largely eliminated by some new optical processing techniques. This paper discusses these two types of optical BFN designs and provides conceptual designs of both systems.
Kunath, R. R.↗
Optoelectronic signal processing for phased-array antennas; Proceedings of the Meeting, Los Angeles, CA, Jan. 12, 13, 1988
Papers are presented on fiber optic links for airborne satellite applications, optoelectronic techniques for broadband switching, and GaAs circuits for a monolithic optical controller. Other topics include the optical processing of covariance matrices for adaptive processors, an optical linear heterodyne matrix-vector processor, and an EHF fiber optic-based array. An adaptive optical signal processing architecture using a signed-digit number system is considered along with microwave fiber optic links for phased arrays.
Bhasin, Kul B.↗
Notes on Array Antenna Phase Center
The location of an antenna, and indeed the radar system it serves, is typically presumed to be its phase center. This is the point from which a far-field apparent spherical wavefront seems to be centered. Even when a true phase center doesn’t exist, an ‘apparent’ phase center can still be calculated for the neighborhood of some direction of interest, often the mainlobe of the beam. Such calculations are especially necessary for non-symmetric arrays, or sub-arrays.
42 ENGINEERING↗
MMIC devices for active phased array antennas
The study of printed circuit discontinuities is necessary in order to design, for example, transitions between rectangular waveguides and printed circuits. New developments with respect to the analytical approaches to this problem are discussed. A summary of the progress in the experimental approach is presented. The accurate solution for the modes in various millimeter-wave waveguides is essential in the analysis of many integrated circuit components, such as filters and impedance transformers. Problems associated with the numerical computation of these modes in two frequently used waveguide forms, namely, the finline and microstrip, are presented. The spectral domain method of formulation, with a moment method solution, is considered. This approach can be readily extended to analyze an arbitrary configuration of dielectric and metallized regions in a shielded enclosure. Galerkin's method is used, where the testing and basic functions are the same. It is shown that the mode functions, or eigenfunctions, are more sensitive to errors than the phase constants, or eigenvalues. The approximate mode functions do not satisfy the orthogonality relationship well, resulting in difficulties when these modal solutions are used to form an approximate Green's function or are used in a mode matching analysis.
Mittra, R.↗
Economical phased-array antenna for environmental applications
Antenna system handles data acquisition and tracking, functions as a sensitive radio telescope, and serves as a radiometer in earth atmosphere investigations. Antenna's sensitivity permits resolution of solar disk quadrants in Doppler radar observations. Antenna also serves as a planetary radar device and link to commercial aircraft.
Higgins, W. T.↗