Results 261 to 270 of about 256,534 (295)

Linear and Circular Polarization from

Astronomische Nachrichten, 2003
We describe recent results for Sgr A*, M81* and other low luminosity active galactic nuclei. We have conducted linear and circular polarimetry over a frequency range of 1.4 to 230 GHz and detected a variety of phenomena. The polarization properties of the studied sources are substantially different from higher powered AGN. In the case of Sgr A*, we are
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Cross-Polarization Reduction of Linear-to-Circular Polarizing Reflective Surfaces

IEEE Antennas and Wireless Propagation Letters, 2019
This letter proposes an efficient design process to reduce the cross polarization of linear-to-circular reflection polarizers illuminated by practical feeds. In particular, we propose a two-step process, where first a geometrical optimization of the unit cell is applied along one plane of the reflector, followed by a progressive rotation of the unit ...
Salvador Mercader-Pellicer, George Goussetis, Gabriela M. Medero, Herve Legay, Daniele Bresciani, Nelson J. G. Fonseca   +5 more
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A Pure Water Linear-to-Circular Polarization Converter

2019 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM), 2019
A linear-to-circular (LTC) polarization converter utilizing pure water is investigated in this paper, which has advantages of high transparency and shorter transmission length due to the very high dielectric constant of pure water. It is made of periodic water slabs surrounded by 3D printed dielectric containers.
Jianpeng Luo, Zibin Chi, Zhuowei Wang, Zhuozhu Chen, Zhenxin Hu, Xin Tian, Duo-Long Wu   +6 more
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A Linear-to-Circular Polarizer Optimized by Simulated Annealing Algorithm

2022 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP), 2022
A compact millimeter-wave polarizer that transforms a linear polarization wave into circular polarization is proposed in this paper. The presented polarizer is made of a single-layer metal plate with three ring slots, and the simulated annealing algorithm (SA) is used to optimize the size of the ring slots, which is much more efficient than the manual ...
Chen, Hui, Zhang, Long, Mao, Chunxu, Dong, Jian, He, Yejun   +4 more
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Broadband Terahertz Linear-to-Circular Polarization Conversion

2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2018
We use a bilayer anisotropic terahertz metasurface to demonstrate broadband linear-to-circular polarization conversion in reflection. In experiments the metasurface structure enables >85% conversion efficiency, 67% fractional bandwidth, and nearly 100% degree of circular polarization.
Chun-Chieh Chang, Hou-Tong Chen
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A X-band linear to circular polarization converter

2017 IEEE 4th International Conference on Knowledge-Based Engineering and Innovation (KBEI), 2017
In this paper, polarization conversion of a simple structure from linear to circular has been investigated. The pattern resulting the desired polarization is composed of slot cross grids which has been analyzed by transmission matrix method (TMM). Given this, frequency band the polarizer supports is from 10.65 GHz to 12 GHz in which the quadrature ...
M. Karamirad, Ch. Ghobadi, J. Nourinia, B. Mohammadi   +3 more
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Multi-band reflective metasurface for efficient linear and circular polarization conversion [PDF]

Optical and Quantum Electronics
This paper introduces a novel reflective metasurface for efficient polarization conversion in the X, Ku, and K bands. Through rigorous simulations and experimental validation, high polarization conversion ratios (PCR) exceeding 90% were achieved, even at
Humayun Zubair Khan, Abdul Jabbar, Jalil Ur Rehman KAZIM   +2 more
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Linear and circular polarization by hollow organic grains

Astrophysics and Space Science, 1989
Hollow cylindrical organic particles with a mean refractive index 1.15 and radius 0.1 μm, coated with a SiO2-Fe mantle of thickness 0.006 μm, are shown to possess wavelength dependences of linear and circular polarization which are in good accord with astronomical data.
F. Hoyle, N. C. Wickramasinghe
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Above-Threshold Ionization with Linear and Circular Polarizations

1987
Ionization in the field of a strong electromagnetic wave had been studied for more than one decade when it was observed that electron spectra were not as predicted by lowest non-vanishing order perturbation theory (LOPT) [1]. Instead of one peak at EO = Nhw-EI (where N is the minimum number of photons ho) required to overcome the ionization potential ...
F. Yergeau, G. Petite, P. Agostini
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Polarization Holographic Recording in Amorphous Polymer with Photoinduced Linear and Circular Birefringence

The Journal of Physical Chemistry B, 2010
Polarization grating recording in an amorphous and nonchiral azo copolymer has been investigated. The reported study shows that the amorphous polymeric film undergoes a light-guided inhomogeneous supramolecular modification as a consequence of the illumination with proper polarized light patterns, acquiring new functionalities. Both linear and circular,
CIPPARRONE, Gabriella, PAGLIUSI, Pasquale, PROVENZANO C, SHIBAEV V.   +3 more
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