Results 151 to 160 of about 632 (194)

Investigation of low‐profile Fresnel zone plate antennas

Microwave and Optical Technology Letters, 2008
AbstractThis article presents low‐profile configurations of the Fresnel zone plate antenna at Ka‐band. The investigation involved progressively reducing the focal distance of the antenna through simulations and observing the effect on the directivity, radiation patterns, and aperture efficiency.
S. M. Stout‐Grandy, A. Petosa, I. V. Minin, O. V. Minin, J. S. Wight   +4 more
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Design of high efficiency Fresnel zone plate antennas

Antennas and Propagation Society Symposium 1991 Digest, 2002
With a family of ideal radiation patterns, the theory for designing high-efficiency phase-correcting FZP (Fresnel zone plate) antennas is presented. The optimum 3-dB beamwidth of the feed pattern as a function of F/D (focal length/diameter) of the plate, the relation between the phase efficiency of the antenna and the number of subzones used in each ...
Y.J. Guo, S.K. Barton, T.M.B. Wright
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Some developments in Fresnel zone plate lens antennas

IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010), 2003
The paper summarizes the basic outcomes of the several years of research on the Fresnel zone plate lenses and antennas accomplished at the Eindhoven University of Technology (EUT). Added are also some results obtained at the Technical University of Vama (TUV) as an extension of the joint work on the subject between the EUT and the TUV initiated under a
Herben, M.H.A.J., Hristov, H.D.
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Antenna pattern characteristics of phase-correcting Fresnel zone plates

International Symposium on Antennas and Propagation Society, Merging Technologies for the 90's, 1990
The far-field antenna pattern of phase-correcting Fresnel zone plates is analyzed, based primarily on work done in the optical regime. Measured characteristics of zone-plates in the microwave-millimeter-wave region are also presented. Since the zone plate accomplishes focusing through diffraction and interference, rather than refraction, the overall ...
J.E. Garrett, J.C. Wiltse
openaire   +1 more source

Dopler Modul and Phase-Correcting Fresnel Zone Plates Antenna

2007 17th International Crimean Conference - Microwave & Telecommunication Technology, 2007
Doppler module and antenna with phase-correcting plates of Fresnel zone have been developed for millimeter-waves. Presented in this paper are technical characteristics.
Y. L. Solovyov, G. F. Kovtunenko, A. V. Rudakov   +2 more
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An electronically scanned antenna using fresnel zone techniques

IRE International Convention Record, 2005
A novel technique for implementing electronic beam steering of large aperture scattering and receiving arrays is described. The Fresnel zones of an aperture required to form a beam in an arbitrary direction are realized by controlling the output of discrete integrated amplifier-antenna elements distributed over a scattering surface.
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About Antenna Gain Measurement in A Fresnel Zone

IEEE Antennas and Propagation Magazine, 2010
A method for calculating the measurement error of the directivity characteristics for a two-dimensional antenna placed in a Fresnel zone is presented. The calculation method is based on replacement of a planar-area field with rays converging to an observation point, by a convex-area field with parallel rays.
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Properties of antennas focused in the Fresnel zone

Czechoslovak Journal of Physics, 1967
The paper deals with the calculation of the electric field strength distribution of a circular antenna focused in the Fresnel zone. To express the electric field strength distributionnWv−1(w, x) functions defined by Lommel functions of two variables are used. On the basis of the calculated electric field strength distribution the fundamental properties
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Antenna gain and pattern measurement in a Fresnel zone

2008 13th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2008
The method of calculation of a gain measurement error for antenna placed in a Fresnel zone applies to a case of no uniformly exited antennas. The question, as an arrangement in a Fresnel zone has an effect at a measurement of antenna pattern, is considered. Numerical results are given.
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Fresnel Zone Antennas

2002
Y. Jay Guo, Stephen K. Barton
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