共查询到20条相似文献,搜索用时 703 毫秒
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Appearance of a dc component (normal to the applied dc electric field) in the electric current induced in graphene by an elliptically
polarized electromagnetic wave propagating normally to the sample plane is studied by a direct Monte Carlo numerical simulation.
The dependence of the current on the frequency of the incident wave and the phase shift between its components is analyzed. 相似文献
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Two types of converters for generating a circularly polarized wave from a linearly polarized one are analyzed using the spatial network method (SNM). The converter types studied are: those loaded with metal plates in a cylindrical waveguide and those loaded with a fin. The cutoff wavelengths are computed from the frequency response by applying the fast Fourier transform. The phase-shift constants and guide wavelengths are computed from the spatial and time variations of the electric field distribution. The whole distribution of fields obtained by the SNM is shown to provide detailed information on the field properties, such as the local field concentration. In particular, the process of generating either a circularly or elliptically polarized wave from a linearly polarized wave is shown by three-dimensional and time-domain analysis. It is confirmed that the fundamental characteristics of the converters agree well with the analysis and measured results 相似文献
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Monzurul M. Ehsan Dikshitulu K. Kalluri 《Journal of Infrared, Millimeter and Terahertz Waves》2003,24(8):1215-1234
The transformation of an elliptically polarized standing wave in a cavity by a suddenly and uniformly created plasma is discussed. Theoretical expressions for the plasma induced wiggler magnetic field as well as the frequency-upshifted standing wave are derived. By choosing appropriate values of the source wave parameters and plasma parameters, one can get wiggler magnetic field of desired magnitude, direction and wiggler wavelength. A few representative results are discussed. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1967,55(9):1631-1632
The governing equations for electromagnetic fields in an anisotropic plasma imbedded in a moving dielectric medium are obtained. Examination of the wave and dispersion equations yields information on the elliptically or linearly polarized waves which may exist when the external magnetic field is parallel or perpendicular to the direction of motion, respectively. 相似文献
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Hanninen I. Pitkonen M. Nikoskinen K.I. Sarvas J. 《Antennas and Propagation, IEEE Transactions on》2006,54(4):1167-1173
A method of moments (MoM) formulation is developed to analyze the backscattering properties of an anisotropic trihedral corner reflector, which is obtained by corrugating one or several of its interior faces. The proposed formulation treats the corrugated surface as ideally tuned to the incident wave frequency. The numerical analysis of the studied structures has been done using closed-form formulas and accurate numerical integration. The focus of the study reported in this paper has been the polarization responses of ideally tuned corrugated reflectors, which have interesting properties, particularly regarding elliptically or circularly polarized waves. We numerically verify that an appropriately corrugated reflector returns elliptically and circularly polarized waves with the same handedness as the incident wave. For a linearly polarized incident wave, the corner reflector is able to rotate them by 90/spl deg/. Also the effect of the direction of the corrugation to the backscattering properties is studied. 相似文献
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Semiconductors - In this paper, we investigate the features of reflection of a plane elliptically polarized electromagnetic wave fallen from isotropic transparent dielectric on a layer of... 相似文献
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This paper presents the derivation of equations necessary to calculate noise temperature of a lossy flat-plate reflector. Reflector losses can be due to metallic surface resistivity and multilayer dielectric sheets, including thin layers of plating, paint, and primer on the reflector surface. The incident wave is elliptically polarized, which is general enough to include linear and circular polarizations as well. The derivations show that the noise temperature for the circularly polarized incident wave case is simply the average of those for perpendicular and parallel polarizations 相似文献
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The deterministic prediction of both transient and CW field coupling to large complex electrical systems poses such a formidable problem that other approaches to predicting the coupling may be useful The continuous wave coupling to a complicated electrical system is analyzed in terms of random small dipole interactions in the low-frequency limit (wavelengthsgg system components' sizes). Both random coupling to the incident wave and random interactions among the dipoles are considered. The variables being randomized are the incident direction and polarization, the sizes and orientations of the dipoles, the mutual coupling strengths, and the lumped load impedances. The resulting normalized current distributions are shown to be insensitive to the details of the model except at the extremely low and high percentiles. The magnetic dipole case is investigated in detail. Its resulting induced current distribution roughly resembles, but is not, a log-normal distribution with a standard deviation in the vicinity ofsim6 dB. This result provides insight into some recent measurements obtained for EMP transient field coupling to large systems. An important implication of the results is that for a variety of complicated systems, essentially consisting of many small elements that the coupling is dominated by low-frequency magnetic fields, the central parts of the induced current probability distributions are similar and nearly log-normal. However, conclusions based on the extrapolation of log-normality from measured values near the median to the extreme percentiles may be susceptible to sizeable errors. The electric dipole ease is presented very briefly here, only to the extent of its basic formulations. We refer interested readers to our original report for some basic results for this case and also for the effects caused by an elliptically polarized incident wave versus a linearly polarized one. 相似文献
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线偏振光通过前后摆放顺序不同的λ/4波片和λ/2波片,其出射光的偏振态将被改变,偏振态的变换在激光偏光技术和光信息中应用越来越广。文章利用矩阵光学方法分析按一定方位角摆放的λ/4波片和λ/2波片,在线偏振光通过后的偏振态变化,主要给出了获得椭圆率角不变、椭圆方位角可连续变化和椭圆率角可连续变化、椭圆方位角不变的椭圆偏振光的方法。 相似文献
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The Stoneley problem is analytically solved for the piezoheterolayers of cubic symmetry crystals for the first time. New types of acoustoelectric waves, in contrast to classical Stoneley waves, are plane-polarized in the direction orthogonal to the sagittal plane. The wave electric field in each layer is elliptically polarized in the sagittal plane. The use of new types of acoustoelectric waves will make it possible to significantly extend the capability of modern acoustoelectronic devices and is directly associated with the transition from acoustoelectronics to acoustonanoelectronics corresponding to the nanometer wavelength range with a carrier frequency of the order of hundreds of gigahertz. 相似文献
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Monzurul M. Ehsan Dikshitulu K. Kalluri 《Journal of Infrared, Millimeter and Terahertz Waves》2003,24(10):1655-1676
The transformation of an elliptically polarized standing source wave in a cavity by a lossy plasma created with arbitrary space and time profiles is numerically computed using the Finite-Difference Time-Domain (FDTD) method. The FDTD equations derived are shown to be very robust and results are presented for several practical scenarios. 相似文献
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为了研究超短超强椭圆偏振激光初始相位对于高能电子辐射特性的影响, 采用了Lorentz方程与电子能量方程构造高能电子与强激光场的对撞模型的方法, 并使用MATLAB进行数值模拟, 获得了电子的运动轨迹以及激光场空间辐射的功率与能量分布的数据与图像, 对不同的激光初始相位所对应的3维空间辐射特性进行了研究。结果表明, 当激光脉冲撞击电子时, 电子产生辐射, 且辐射功率呈现出双峰形; 高能电子的辐射功率图像在初始相位为0°, 180°和360°时表现为对称型双峰, 而在其它相位下则呈现出非对称型双峰。该结论为超短超强椭圆偏振激光的初始相位3维反探测研究提供了一定的基础。 相似文献
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《Photonics Technology Letters, IEEE》2009,21(14):1008-1010
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