Results 111 to 120 of about 87,657 (169)
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An improved zoning rule of the Fresnel zone plate
Microwave and Optical Technology Letters, 1999In the traditional zoning rule of the Fresnel zone plate (FZP), the distance from two edges of each zone to a common focus is progressively increased with a half-wavelength step. In this paper, a more reasonable zoning rule is proposed to further increase the antenna gain by about 1 dB. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 69–73,
exaly +2 more sources
Solution to the Fresnel Zone Plate Problem
American Journal of Physics, 1969The diffraction problem for the Fresnel half-period zone plate is solved. The zone plate behaves as a lens with marked chromatism which can be taken advantage of for use in a spectrometer. The multiplicity of foci associated with the zone plate are examined in detail, and it is shown that the spectral range that can be focused without overlap is 3λmin ...
H. Malcolm Childers, David E. Stone
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Ultrasonics, 2022
Acoustic focusing with high energy intensity, broadband and few side lobes properties are highly demanded in many fields and can be achieved with Fresnel zone plate (FZP) lens as an artificial structure.
Xiaojiang J. Pan +4 more
semanticscholar +1 more source
Acoustic focusing with high energy intensity, broadband and few side lobes properties are highly demanded in many fields and can be achieved with Fresnel zone plate (FZP) lens as an artificial structure.
Xiaojiang J. Pan +4 more
semanticscholar +1 more source
IEEE Transactions on Antennas and Propagation, 2021
This article presents an aperture-shared dual-band large frequency-ratio high gain antenna for sub-6 GHz and millimeter-wave (mm-wave) bands applications. Initially, the partially reflective surface (PRS) of the Fabry–Pérot cavity (FPC) antenna operating
Jianfeng Zhu, Yang Yang, S. Liao, Q. Xue
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This article presents an aperture-shared dual-band large frequency-ratio high gain antenna for sub-6 GHz and millimeter-wave (mm-wave) bands applications. Initially, the partially reflective surface (PRS) of the Fabry–Pérot cavity (FPC) antenna operating
Jianfeng Zhu, Yang Yang, S. Liao, Q. Xue
semanticscholar +1 more source
Study of focusing parameters of wavelength-scale binary phase Fresnel zone plate
Journal of Optics, 2021Binary Fresnel zone plates (FZP) are among the most commonly used focusing elements of 2D-planar optical circuits in micro- and nano-photonics. When the diameter and focal distance of a FZP are reduced to the wavelength dimensions, the parameters of the ...
Yuri E. Geints +3 more
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Gold filled in Fresnel zone plate fabricated by femtosecond laser on fiber tip
Optical fiber technology (Print), 2021We present a method to fabricate Fresnel zone plate (FZP) on the multimode fiber (MMF) tip by combining femtosecond laser direct writing with coating, polishing and chemical etching.
Cong Xu +5 more
semanticscholar +1 more source
, 2021
Accurate measurement of the contact stress on the mating surface of the core engine's multi-stage rotor is of great significance for improving the structural connection quality and comprehensive performance of aero-engines.
Enxiao Liu +6 more
semanticscholar +1 more source
Accurate measurement of the contact stress on the mating surface of the core engine's multi-stage rotor is of great significance for improving the structural connection quality and comprehensive performance of aero-engines.
Enxiao Liu +6 more
semanticscholar +1 more source
Implementation of a 2-D Reconfigurable Fresnel-Zone-Plate Antenna
IEEE Transactions on Antennas and Propagation, 2021Combining the advantages of the phase tunability provided by active frequency selective surfaces (FSSs) and the beam-steering scheme used in conventional 1-D Fresnel-zone-plate (FZP) antennas, we report in this communication a 2-D beam-steering FZP ...
Chao Ma +8 more
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Dielectrophoretically controlled Fresnel zone plate
Lab on a Chip, 2015We present a novel switchable Fresnel zone plate, created using nanoparticle suspensions which are controlled by dielectrophoresis.
A F, Chrimes +4 more
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The Bandwidth of Fresnel-Zone Plate Antennas
Journal of Electromagnetic Waves and Applications, 1997Theoretical expressions are presented for the illumination and phase efficiency of three types of Fresnel-zone plate antennas. Using these formulas, the bandwidths of the antennas will be analyzed and compared. Measured data are given to validate the theoretical results.
van Houten, J.M., Herben, M.H.A.J.
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