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考虑多层土壤时架空线的瞬态分析 被引量:22
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作者 齐磊 卢铁兵 +1 位作者 张重远 崔翔 《中国电机工程学报》 EI CSCD 北大核心 2003年第5期66-69,共4页
基于麦克斯韦方程组,推导出土壤水平分层时电磁波在土壤中透射深度的计算公式,按照复深度法可进一步得到土壤阻抗的频域形式。为了便于时域卷积,采用矢量匹配法并结合拉普拉斯反变换将该土壤阻抗的时域形式展开为有限项指数函数之和,并... 基于麦克斯韦方程组,推导出土壤水平分层时电磁波在土壤中透射深度的计算公式,按照复深度法可进一步得到土壤阻抗的频域形式。为了便于时域卷积,采用矢量匹配法并结合拉普拉斯反变换将该土壤阻抗的时域形式展开为有限项指数函数之和,并验证了方法的正确性。最后,采用时域有限差分法(FDTD)对架空线的瞬态波过程进行仿真计算,结果表明:土壤阻抗对自阻抗影响较小,对互阻抗影响较大。通过与电磁暂态计算软件(EMTP)的计算结果比较,验证了所提出的FDTD算法的有效性,同时也表明了计入土壤损耗及考虑分层土壤的必要性。 展开更多
关键词 输电线路 架空线路 瞬态分析 电磁波 矢量匹配 时域有限差法 土壤阻抗
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Application of Padé Approximation in Simulating Photonic Crystals 被引量:2
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作者 黄永箴 陈沁 +1 位作者 国伟华 于丽娟 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第7期1281-1286,共6页
To save finite-difference time-domain(FDTD) computing time, several methods are proposed to convert the time domain FDTD output into frequency domain. The Pad6 approximation with Baker's algorithm and the program a... To save finite-difference time-domain(FDTD) computing time, several methods are proposed to convert the time domain FDTD output into frequency domain. The Pad6 approximation with Baker's algorithm and the program are introduced to simulate photonic crystal structures. For a simple pole system with frequency 160THz and quality factor of 5000, the intensity spectrum obtained by the Padé approximation from a 2^8-item sequence output is more exact than that obtained by fast Fourier transformation from a 2^20-item sequence output. The mode frequencies and quality factors are calculated at different wave vectors for the photonic crystal slab from a much shorter FDTD output than that required by the FFT method, and then the band diagrams are obatined. In addition, mode frequencies and Q-factors are calculated for photonic crystal microcavity. 展开更多
关键词 optical waveguides photonic bandgap photonic crystal MICROCAVITY finite-difference time-domain
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Numerical analysis of multicomponent responses of surface-hole transient electromagnetic method 被引量:3
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作者 孟庆鑫 胡祥云 +1 位作者 潘和平 周峰 《Applied Geophysics》 SCIE CSCD 2017年第1期175-186,192,共13页
We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular... We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets. 展开更多
关键词 Surface-hole transient electromagnetic method multicomponent response analysis transient electric field three-dimensional finite-difference time-domain method discrete image method
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Improved absorbing boundary condition based on linear interpolation for ADI-FDTD method 被引量:1
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作者 赵嘉宁 《Journal of Southeast University(English Edition)》 EI CAS 2009年第3期289-293,共5页
With the linear interpolation method, an improved absorbing boundary condition(ABC)is introduced and derived, which is suitable for the alternating-direction-implicit finite- difference time-domain (ADI-FDTD) meth... With the linear interpolation method, an improved absorbing boundary condition(ABC)is introduced and derived, which is suitable for the alternating-direction-implicit finite- difference time-domain (ADI-FDTD) method. The reflection of the ABC caused by both the truncated error and the phase velocity error is analyzed. Based on the phase velocity estimation and the nonuniform cell, two methods are studied and then adopted to improve the performance of the ABC. A calculation case of a rectangular waveguide which is a typical dispersive transmission line is carried out using the ADI-FDTD method with the improved ABC for evaluation. According to the calculated case, the comparison is given between the reflection coefficients of the ABC with and without the velocity estimation and also the comparison between the reflection coefficients of the ABC with and without the nonuniform processing. The reflection variation of the ABC under different time steps is also analyzed and the acceptable worsening will not obscure the improvement on the absorption. Numerical results obviously show that efficient improvement on the absorbing performance of the ABC is achieved based on these methods for the ADI-FDTD. 展开更多
关键词 alternating-direction-implicit finite-difference time- domain ADI-FDTD method absorbing boundary condition (ABC) linear interpolation phase velocity nonuniform cell
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Full Wave Analysis of a Broad Wall Waveguide Slot Coupler
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作者 任武 丁四如 高本庆 《Journal of Beijing Institute of Technology》 EI CAS 2002年第4期364-368,共5页
A rigorous analysis of a broad wall slot coupler composed of two crossed rectangular waveguides by using FDTD method is presented. Two types of slots, a longitudinal/transverse slot and a centered-inclined slot, are a... A rigorous analysis of a broad wall slot coupler composed of two crossed rectangular waveguides by using FDTD method is presented. Two types of slots, a longitudinal/transverse slot and a centered-inclined slot, are analyzed. Coupling slot characteristics are obtained, including scattering parameters and the resonant length for different waveguide dimensions and frequencies. The numerical results are all in good agreement with those by the method of moments. A coupler system with a short circuit port is also analyzed to help designing the slot array. 展开更多
关键词 slot coupler FDTD longitudinal/transverse slot centered-inclined slot
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Orthogonal experiment design of EMI of security monitoring system in coal mines 被引量:20
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作者 Xiang Liu Chaoqun Jiao Aifen Yao 《International Journal of Coal Science & Technology》 EI 2015年第4期325-332,共8页
Security monitoring system of coal mines is indispensable to ensure the safe and efficient production of colliery. Due to the special and narrow underground field of the coal mine, the electromagnetic interference can... Security monitoring system of coal mines is indispensable to ensure the safe and efficient production of colliery. Due to the special and narrow underground field of the coal mine, the electromagnetic interference can cause a series of misstatements and false positives on the monitoring system, which will severely hamper the safe production of coal industry. In this paper, first, the frequency characteristics of the interference source on the power line are extracted when equipment runs normally. Then the finite difference time domain method is introduced to analyze the effects of the electromagnetic interference parameters on the security monitoring signal line. And the interference voltage of the two terminal sides on the single line is taken as evaluating indexes. Finally, the electromagnetic interference parameters are optimized by orthogonal experimental design based on the MATLAB simulation on the normal operation of equipment. 展开更多
关键词 Security monitoring system Finite difference time domain method (FDTD) Electromagnetic interference(EMI) Orthogonal experimental design
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Borehole-GPR numerical simulation of full wave field based on convolutional perfect matched layer boundary 被引量:7
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作者 朱自强 彭凌星 +1 位作者 鲁光银 密士文 《Journal of Central South University》 SCIE EI CAS 2013年第3期764-769,共6页
The absorbing boundary is the key in numerical simulation of borehole radar.Perfect match layer(PML) was chosen as the absorbing boundary in numerical simulation of GPR.But CPML(convolutional perfect match layer) appr... The absorbing boundary is the key in numerical simulation of borehole radar.Perfect match layer(PML) was chosen as the absorbing boundary in numerical simulation of GPR.But CPML(convolutional perfect match layer) approach that we have chosen has the advantage of being media independent.Beginning with the Maxwell equations in a two-dimensional structure,numerical formulas of finite-difference time-domain(FDTD) method with CPML boundary condition for transverse electric(TE) or transverse magnetic(TM) wave are presented in details.Also,there are three models for borehole-GPR simulation.By analyzing the simulation results,the features of targets in GPR are obtained,which can provide a better interpretation of real radar data.The results show that CPML is well suited for the simulation of borehole-GPR. 展开更多
关键词 borehole-GPR numerical simulation convolutional perfect match layer finite-difference time-domain method
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Modulation of Photonic Bandgap and Localized States by Dielectric Constant Contrast and Filling Factor in Photonic Crystals
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作者 陈沁 黄永箴 +1 位作者 国伟华 于丽娟 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第12期1233-1238,共6页
The band structure of 2D photonic crystals (PCs) and localized states resulting from defects are analyzed by finite-difference time-domain (FDTD) technique and Padé approximation.The effect of dielectric constant... The band structure of 2D photonic crystals (PCs) and localized states resulting from defects are analyzed by finite-difference time-domain (FDTD) technique and Padé approximation.The effect of dielectric constant contrast and filling factor on photonic bandgap (PBG) for perfect PCs and localized states in PCs with point defects are investigated.The resonant frequencies and quality factors are calculated for PCs with different defects.The numerical results show that it is possible to modulate the location,width and number of PBGs and frequencies of the localized states only by changing the dielectric constant contrast and filling factor. 展开更多
关键词 photonic crystals photonic bandgap defect states FDTD
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Parallel computation of unified finite-difference time-domain for underwater sound scattering 被引量:2
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作者 冯玉田 王朔中 《Journal of Shanghai University(English Edition)》 CAS 2008年第2期120-125,共6页
In this work, we treat scattering objects, water, surface and bottom in a truly unified manner in a parallel finitedifference time-domain (FDTD) scheme, which is suitable for distributed parallel computing in a mess... In this work, we treat scattering objects, water, surface and bottom in a truly unified manner in a parallel finitedifference time-domain (FDTD) scheme, which is suitable for distributed parallel computing in a message passing interface (MPI) programming environment. The algorithm is implemented on a cluster-based high performance computer system. Parallel computation is performed with different division methods in 2D and 3D situations. Based on analysis of main factors affecting the speedup rate and parallel efficiency, data communication is reduced by selecting a suitable scheme of task division. A desirable scheme is recommended, giving a higher speedup rate and better efficiency. The results indicate that the unified parallel FDTD algorithm provides a solution to the numerical computation of acoustic scattering. 展开更多
关键词 parallel computation finite-difference time-domain (FDTD) message passing interface (MPI) object scattering.
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Formation mechanism and modulation of electromagnetically induced transparency-like transmission in side-coupled structures 被引量:2
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作者 杨辉 李宏建 +3 位作者 许秀科 何智慧 王云 徐国均 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第6期2020-2026,共7页
Based on Fabry model and finite-different time-domain(FDTD) method, the plasmonic structure composed of a metal-insulator-metal(MIM) bus waveguide and a side-coupled resonator was investigated. It is found that the tr... Based on Fabry model and finite-different time-domain(FDTD) method, the plasmonic structure composed of a metal-insulator-metal(MIM) bus waveguide and a side-coupled resonator was investigated. It is found that the transmission features can be regulated by the cavity width and coupling distance. Electromagnetically induced transparency(EIT)-like transmission can be excited by adding an identical resonator on the pre-existing structure. Combining the foregoing theoretical analysis with coupled mode theory(CMT), the formation process of the EIT-like transmission was detailedly analyzed. EIT-like transmission can also be excited in plasmonic structure with two detuned resonators. By altering the structure parameters, the transparency window can be purposefully modulated. With the merits of compact structure and simplicity in fabrication, the proposed structures may have a broad prospect of applications in highly integrated optical circuits. 展开更多
关键词 metal-insulator-metal (MIM) waveguide side-coupled resonator electromagnetically induced transpareucy (EIT)-like transmission formation mechanism
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Calculation and application of full-wave airborne transient electromagnetic data in electromagnetic detection 被引量:2
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作者 JI Yan-ju ZHU Yu +2 位作者 YU Ming-mei LI Dong-sheng GUAN Shan-shan 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第4期1011-1020,共10页
Airborne electromagnetic transient method enjoys the advantages of high-efficiency and the high resolution of electromagnetic anomalies,especially suitable for mining detection around goaf areas and deep exploration o... Airborne electromagnetic transient method enjoys the advantages of high-efficiency and the high resolution of electromagnetic anomalies,especially suitable for mining detection around goaf areas and deep exploration of minerals.In this paper,we calculated the full-wave airborne transient electromagnetic data,according to the result of numerical research,the advantage of switch-off time response in electromagnetic detection was proofed via experiments.Firstly,based on the full-wave airborne transient electromagnetic system developed by Jilin University(JLU-ATEMI),we proposed a method to compute the full-waveform electromagnetic(EM)data of 3D model using the FDTD approach and convolution algorithm,and verify the calculation by the response of homogenous half-space.Then,through comparison of switch-off-time response and off-time response,we studied the effect of ramp time on anomaly detection.Finally,we arranged two experimental electromagnetic detection,the results indicated that the switch-off-time response can reveal the shallow target more effectively,and the full-waveform airborne electromagnetic system is an effective technique for shallow target detection. 展开更多
关键词 airborne electromagnetic transient method full-waveform FDTD approach convolution algorithm anomaly detection
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Modeling transmittance through submicron silver slit arrays 被引量:1
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作者 王爱华 蔡九菊 陈玉彬 《Journal of Central South University》 SCIE EI CAS 2012年第8期2107-2114,共8页
Mid-infrared transmittance of submicron silver slit arrays was numerically studied with the finite difference time domain method. The slit width varies from 50 nm to 300 nm and a square feature may attach at either or... Mid-infrared transmittance of submicron silver slit arrays was numerically studied with the finite difference time domain method. The slit width varies from 50 nm to 300 nm and a square feature may attach at either or both slit sides. Although the side length of features is one or two orders of magnitude shorter than the wavelength, the attached nanoscale features can modify the transmittance significantly. The transmittance was also further investigated in detail by looking into the electromagnetic fields and Poynting vectors of selected slit geometries. The investigation results show that such change can be attributed to the cavity resonance effect inside the slit arrays. The work is of great importance to the wavelength-selective devices design in optical devices and thermal application fields. 展开更多
关键词 finite difference time domain method TRANSMITTANCE silver slit array cavity resonance effect
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Modeling of radiative properties of metallic microscale rough surface 被引量:1
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作者 王爱华 蔡九菊 《Journal of Central South University》 SCIE EI CAS 2012年第6期1482-1487,共6页
The radiative properties of a gold surface with one-dimensional Gaussian random roughness distribution were obtained with the finite-difference time-domain (FDTD) method and the recursive convolution treatment of th... The radiative properties of a gold surface with one-dimensional Gaussian random roughness distribution were obtained with the finite-difference time-domain (FDTD) method and the recursive convolution treatment of the Drude Model. The bi-directional reflection distribution function (BRDF) for both TM mode and TE mode were obtained and compared with the highly accurate experimental data from the earlier work. The incident wavelength varies from 1.152 μm to 3.392 μm and incident angle is at 300-70°, respectively. The results show that, the predicted values and experimental results are in good agreement. The highly specular peak in the BRDF is reproduced in the numerical simulations, and the increase of the TM mode BRDF is found to be attributed to the effect of a variation in the optical constant at the incident wavelength period. 展开更多
关键词 bi-directional reflection distribution function Gaussian random roughness distribution gold surface finite-differencetime-domain method
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Finite difference time domain method forward simulation of complex geoelectricity ground penetrating radar model 被引量:5
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作者 戴前伟 冯德山 何继善 《Journal of Central South University of Technology》 EI 2005年第4期478-482,共5页
The ground penetrating radar(GPR) forward simulation all aims at the singular and regular models, such as sandwich model, round cavity, square cavity, and so on, which are comparably simple. But as to the forward of c... The ground penetrating radar(GPR) forward simulation all aims at the singular and regular models, such as sandwich model, round cavity, square cavity, and so on, which are comparably simple. But as to the forward of curl interface underground or “v” figure complex model, it is difficult to realize. So it is important to forward the complex geoelectricity model. This paper takes two Maxwell’s vorticity equations as departure point, makes use of the principles of Yee’s space grid model theory and the basic principle finite difference time domain method, and deduces a GPR forward system of equation of two dimensional spaces. The Mur super absorbed boundary condition is adopted to solve the super strong reflection on the interceptive boundary when there is the forward simulation. And a self-made program is used to process forward simulation to two typical geoelectricity model. 展开更多
关键词 ground penetrating radar finite difference time domain method forward simulation ideal frequency dispersion relationship
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微波探伤在纤维加劲聚合物外敷混凝土结构上的应用
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作者 王庆水 《世界桥梁》 2003年第2期44-49,共6页
在早期规范中 ,钢筋混凝土柱抗震加固的设计和施工 ,通常使用纤维加劲聚合物 (FRP)外敷技术。介绍了一种用于探测外敷层与混凝土柱间缺陷的电磁成像 (简称EM)技术。该技术还可用于评定外敷层施工质量 。
关键词 微波探伤 纤维加劲聚合物 混凝土结构 钢筋立柱 外敷技术 电磁成像技术 介电参数 反射仪 有限时域 电介透镜
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Modeling infrared radiative properties of nanoscale metallic complex slit arrays
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作者 王爱华 牛义红 陈玉彬 《Journal of Central South University》 SCIE EI CAS 2014年第10期3927-3935,共9页
The radiative properties(absorptance, reflectance, and transmittance) of deep slits with five nanoscale slit profile variations at the transverse magnetic wave incidence were numerically investigated by employing the ... The radiative properties(absorptance, reflectance, and transmittance) of deep slits with five nanoscale slit profile variations at the transverse magnetic wave incidence were numerically investigated by employing the finite difference time domain method. For slits with attached features, their radiative properties can be much different due to the modified cavity geometry and dangled structures, even at wavelengths between 3 and 15 μm. The shifts of cavity resonance excitation result in higher transmittance through narrower slits at specific wavelengths and resonance modes are confirmed with the electromagnetic fields. Opposite roles possibly played by features in increasing or decreasing absorptance are determined by the feature position and demonstrated by Poynting vectors. Correlations among all properties of a representative slit array and the slit density are also comprehensively studied. When multiple slit types coexist in an array(complex slits), a wide-band transmittance or absorptance enhancement is feasible by merging spectral peaks contributed from each type of slits distinctively. Discrepancy among infrared properties of four selected slit combinations is explained while effects of slit density are also discussed. 展开更多
关键词 finite difference time domain method subwavelength structures radiative properties complex slit arrays cavity resonance
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3D prestack reverse time migration of ground penetrating radar data based on the normalized correlation imaging condition
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作者 Wang Hong-Hua Gong Jun-bo +4 位作者 Zhang Zhi Xiong Bin Lv Yu-zeng Feng De-shan Dai Qian-wei 《Applied Geophysics》 SCIE CSCD 2020年第5期709-718,901,共11页
The reverse time migration(RTM)of ground penetrating radar(GPR)is usually implemented in its two-dimensional(2D)form,due to huge computational cost.However,2D RTM algorithm is difficult to focus the scattering signal ... The reverse time migration(RTM)of ground penetrating radar(GPR)is usually implemented in its two-dimensional(2D)form,due to huge computational cost.However,2D RTM algorithm is difficult to focus the scattering signal and produce a high precision subsurface image when the object is buried in a complicated subsurface environment.To better handle the multi-off set GPR data,we propose a three-dimensional(3D)prestack RTM algorithm.The high-order fi nite diff erence time domian(FDTD)method,with the accuracy of eighth-order in space and second-order in time,is applied to simulate the forward and backward extrapolation electromagnetic fi elds.In addition,we use the normalized correlation imaging condition to obtain pre-stack RTM result and the Laplace fi lter to suppress the low frequency noise generated during the correlation process.The numerical test of 3D simulated GPR data demonstrated that 3D RTM image shows excellent coincidence with the true model.Compared with 2D RTM image,the 3D RTM image can more clearly and accurately refl ect the 3D spatial distribution of the target,and the resolution of the imaging results is far better.Furthermore,the application of observed GPR data further validates the eff ectiveness of the proposed 3D GPR RTM algorithm,and its fi nal image can more reliably guide the subsequent interpretation. 展开更多
关键词 Ground Penetrating Radar(GPR) 3D Reverse Time Migration(RTM) Finite Diff erence Time Domain(FDTD) Normalized correlation imaging condition
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Polarization insensitivity electromagnetically induced reflection in graphene metasurface
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作者 WANG Jin WANG Xingchen +1 位作者 GAO Xiang NING Renxia 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第3期362-368,共7页
The electromagnetically induced reflection(EIR)effect of graphene metamaterials has been investigated by finite difference time domain(FDTD)method.In this study,a metamaterial sandwich structure composed of silica(SiO... The electromagnetically induced reflection(EIR)effect of graphene metamaterials has been investigated by finite difference time domain(FDTD)method.In this study,a metamaterial sandwich structure composed of silica(SiO2),gold and graphene on terahertz band is designed.By changing the width of the two ribbons of graphene length and the incident angle of electromagnetic wave,the EIR effect of the structure is discussed,and it can be found that SiO2 is a kind of excellent dielectric material.The simulation results show that graphene metamaterial is not sensitive to polarized incident electromagnetic wave.Therefore,such EIR phenomena as insensitive polarization and large incident angle can be applied to optical communication filters and terahertz devices. 展开更多
关键词 electromagnetically induced reflection(EIR) graphene metamaterials polarization insensitivity finite difference time domain(FDTD)method
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Theoretical Analysis on Optical Limiting Properties of Newly Synthesized Graphene Oxide-Porphyrin Composites
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作者 Yu-jin Zhang Wen-jing Yang +2 位作者 Jian-zhong Fan Yu-zhi Song Chuan-kui Wang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2015年第3期257-262,I0001,共7页
Optical limiting (OL) properties and two-photon absorption (TPA) of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and f... Optical limiting (OL) properties and two-photon absorption (TPA) of a series of covalently linked graphene oxide-porphyrin composite materials have been investigated by numerically solving the rate equations and field intensity equation with an iterative predictor-corrector finite-difference time-domain technique in nanosecond time domain. Our results show that graphene oxide-porphyrin composites exhibit enhanced OL behavior and possess larger TPA cross section compared with individual porphyrins. Interestingly~ unlike the previous result that porphyrin with heavier central metal shows better nonlinear abilities than that with- out metal substitute, graphene oxide-metal free porphyrin composite has stronger nonlinear absorption properties compared with graphene oxide-metal porphyrin composite. The com- putational results are in reasonable agreement with the experimental ones. Special attention has been paid to the influence of thickness of the medium and pulse width on TPA cross sections, which presents that larger TPA cross sections are obtained as the medium is thicker or the pulse duration is wider. 展开更多
关键词 Optical limiting Two-photon absorption Graphene oxide PORPHYRIN
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Modeling bidirectional reflection distribution function of microscale random rough surfaces
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作者 王爱华 HSU P.F. 蔡九菊 《Journal of Central South University》 SCIE EI CAS 2010年第2期228-234,共7页
The radiative properties of three different materials surfaces with one-dimensional microscale random roughness were obtained with the finite difference time domain method(FDTD) and near-to-far-field transformation.Th... The radiative properties of three different materials surfaces with one-dimensional microscale random roughness were obtained with the finite difference time domain method(FDTD) and near-to-far-field transformation.The surface height conforms to the Gaussian probability density function distribution.Various computational modeling issues that affect the accuracy of the predicted properties were discussed.The results show that,for perfect electric conductor(PEC) surfaces,as the surface roughness increases,the magnitude of the spike reduces and eventually the spike disappears,and also as the ratio of root mean square roughness to the surface correlation distance increases,the retroreflection becomes evident.The predicted values of FDTD solutions are in good agreement with the ray tracing and integral equation solutions.The overall trend of bidirectional reflection distribution function(BRDF) of PEC surfaces and silicon surfaces is the same,but the silicon's is much less than the former's.The BRDF difference from two polarization modes for the gold surfaces is little for smaller wavelength,but it is much larger for the longer wavelength and the FDTD simulation results agree well with the measured data.In terms of PEC surfaces,as the incident angle increases,the reflectivity becomes more specular. 展开更多
关键词 bidirectional reflection distribution fimction random rough surfaces Maxwell equations finite difference time domain method
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