Results 151 to 160 of about 152,416 (209)
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A Multibeam Cassegrain Antenna
1975 5th European Microwave Conference, 1975This paper deals with generation of a multibeam pattern for three-dimensional radar surveillance by a stacked feed horn system installed in a Cassegrain antenna. Although its effective f/D-ratio is relatively high compared with the corresponding one of the primarily feed paraboloid, lateral displacement of feed horns in the focal plane results in ...
H. Gniss, E. Zocher
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Digest on Antennas and Propagation Society International Symposium, 2003
A multibeam antenna prototype for an ESM system is presented. The antenna is formed by a semicircular array of Vivaldi radiating elements, fed by an RKR microstrip lens. Both the lens and the array are printed on the same dielectric substrate. The antenna operates over one octave frequency band.
M. Sierra +3 more
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A multibeam antenna prototype for an ESM system is presented. The antenna is formed by a semicircular array of Vivaldi radiating elements, fed by an RKR microstrip lens. Both the lens and the array are printed on the same dielectric substrate. The antenna operates over one octave frequency band.
M. Sierra +3 more
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Multibeam antennas for indoor wireless communications
IEEE Transactions on Communications, 2002A multibeam beamformer in combination with a decision feedback equalizer is considered for the base station in a single-cell 100-Mb/s TDMA/TDD QPSK indoor wireless network at 24 GHz. The outage rate in terms of required SNR/bit/antenna is estimated using a statistical, clustered propagation model and for beam selection diversity and two-beam combining.
Kuo-Hui Li +2 more
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Advances in multibeam communications satellite antennas
Proceedings of the IEEE, 1990The evolution of satellite antennas over the past quarter of a century is presented. Five major areas of advances in communications satellite antenna technology are reviewed: single offset reflectors with feed arrays, shaped reflector systems, active phased arrays, phased-array-fed dual reflector systems, and lightweight feed elements.
Amir I. Zaghloul +3 more
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IEEE Transactions on Microwave Theory and Techniques, 1992
The Advanced Communication Technology Satellite (ACTS), to be launched in 1993, is introduced briefly, and then the Ka-band multibeam antenna, consisting of electrically similar 30 GHz receive and 20 GHz transmit offset Cassegrain systems utilizing orthogonal linear polarizations, is described.
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The Advanced Communication Technology Satellite (ACTS), to be launched in 1993, is introduced briefly, and then the Ka-band multibeam antenna, consisting of electrically similar 30 GHz receive and 20 GHz transmit offset Cassegrain systems utilizing orthogonal linear polarizations, is described.
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Multibeam antennas for data communications satellites
Proceedings of the fifth symposium on Data communications - SIGCOMM '77, 1977This paper presents a survey of the state-of-the-art in multibeam antennas, as particularly applicable to data communications satellites, and analyzes a new configuration to meet such specific needs over the U.S. during the 1980's. Three basic forms of multibeam antennas are described—those providing space diversity, polarization diversity and variable-
E. W. Matthews, W. G. Scott, C. C. Han
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Multibeam millimeter wave antenna
The Fifth International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter, and Submillimeter Waves (IEEE Cat. No.04EX828), 2004For realization of special researches with airborne radiophysical complexes at millimeter wave (mm) range, multi-beam antenna systems are widely used with multi-beam patterns forming in space and providing probing signals transmission and reception in the set of defined directions.
S.D. Andrenko +2 more
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1995
The effect of the transformation of a non-homogeneous plane wave into a space one is gaining a wider application in antenna techniques. A planar dielectric waveguide is used as a source of non-homogeneous plane wave. The transformation of a slow surface-wave mode into a space wave is realized by using a diffraction grating.
Yevdokymov, Anatoliy P. +1 more
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The effect of the transformation of a non-homogeneous plane wave into a space one is gaining a wider application in antenna techniques. A planar dielectric waveguide is used as a source of non-homogeneous plane wave. The transformation of a slow surface-wave mode into a space wave is realized by using a diffraction grating.
Yevdokymov, Anatoliy P. +1 more
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The application of a multibeam antenna for 4G
The 2012 International Conference on Advanced Technologies for Communications, 2012There are various antenna schemes which can be used to increase the throughput of the 4th mobile generation (4G) networks such as antenna diversity, beamforming, spatial multiplexing and MIMO (Multiple Input Multiple Output) [1]. With the above antenna schemes OFDMA (Orthogonal Frequency Division Multiple Access) is a suitable selection for 4G.
null Tran Cao Quyen, null Trinh Anh Vu
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On the radiation pattern of a multibeam antenna
IEEE Transactions on Antennas and Propagation, 1976The optimum radiation of a lens antenna with an array feed of M elements is desired, which will exhibit maximum gain in a number ( k ) of specified directions and nulls in other ( j ) specified directions. This optimum is not derived; however, a condition for the optimum is shown to be some superposition of just ( k + j ) individual radiation patterns ...
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