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Ultra wideband pulsed ground penetrating radar (GPR) detects buried object or underground medium characteristic by emitting and receiving pulsed electromagnetic waves. Establishing underground medium equivalent model and studying the electromagnetic wave propagation characteristic in media are very important to GPR data processing and underground object detecting. This paper introduces the actual...
There is an optical diffraction limit for the recording density of conventional optical recording systems. There has been a lot of recent interest in the field of optical storage technologies for the recording methods that are based on near-field optical principles because they have the potential to overcome the limitation by using the localized optical near-field for writing and reading recorded...
Technology of modern communication and channel estimation cannot be separated from the research on electromagnetic problems of the sea surface. Considering the cost and other factors, the electromagnetic simulation method is a very valuable research project. FDTD method can be applied to various electromagnetic problems very well, but when dealing with electrically large problems, there will be a...
As the most standard algorithm, the traditional finite-difference time-domain (FDTD) method, which is explicit second-order accurate in both space and time, has been widely applied to electromagnetic computation and simulation. One of the primary drawbacks associated with the FDTD method is significant accumulated errors from numerical instability, dispersion, anisotropy. To overcome the shortcoming,...
The finite difference time domain (FDTD) method [1] is widely used in electromagnetic simulations. It is an iterative process where the computations in one iteration use the results of its previous iterations. Since the number of iterations are usually very large, FDTD computation requires a large amount of processing time. One the other hand, most of the computations corresponding to the cells in...
Wave propagation in a waveguide of rectangular cross section with perfectly conducting wall containing an inhomogeneous dielectric insert in the form of a parallel-plane diaphragm with an inclusion is simulated numerically. The permittivity of the inclusion is a quantity to be restored from as little information about the scattered field as possible using FDTD numerical solution of Maxwell's equations...
Surface plasmon polaritons (SPPs), which carry the electromagnetic energy along the metal-dielectric interface, have received much attention in the field of the photonic devices because they have potential to realize nanoscale photonic devices with the dimension smaller than the diffraction limit. There are mainly two types of configurations that are composed of metal-insulator-metal (MIM) and insulator-metal-insulator...
The frequency-dependent finite-difference time-domain (FDTD) method has widely been used to treat dispersive materials, e.g., metal at optical frequencies, semiconductors at THz frequencies, water at microwave frequencies, and so on. Unfortunately, the time step size is restricted by the Courant-Friedrichs-Lewy (CFL) condition even for the frequency-dependent FDTD method. To remove this restriction,...
A class of circular or cylindrical devices having some sort of periodic dielectric modulation have recently been gathering growing interest in the field of nano- and micro-photonics. The examples of such devices are microgear lasers, vortex beam emitters, and ring or cage resonators. In most devices so far demonstrated, dielectric profile was uniform or concentric near the center, whereas it was azimuthally...
Numerical simulation of electromagnetic models with multi-scale features is highly challenging owing to the fact that electrically large as well as small features are simultaneously present in the model, which requires the computational domain to be discretized such that the number of degrees of freedom (DoFs) is very large; this, in turn, levies a heavy burden on the computational resources.
Numerical analysis of plasma monopole antenna by using full wave computational electromagnetics technique, finite difference time domain (FDTD) is presented. Here, radiation characteristic of antenna has been studied by changing of plasma parameters like, plasma frequency, degree of ionization, antenna length and presented in detail. The numerical analysis shows that the radiation of plasma column...
Nowadays nanotechnology allows us to size down every single object in our daily life at the nanoscale. Especially, conventional microwave antennas/scatterers are reproduced at nanoscale and have found many applications, including bio-sensing [1], energy harvesting [2], nanoscale communications [3, 4], etc. Most recently, a Nanoparticle-on-Mirror (NPoM) topology with a sub-nm gap size (See Fig. 1,...
It has been demonstrated that photonic band gap can be realized in quasi-periodic photonic crystal. We design a two dimensional octagonal photonic quasicrystal composed of alumina cylinders. The photonic band gaps are theoretically examined by the Transfer Matrix Method (TMM) and Finite-Difference Time-Domain (FDTD) for transverse magnetic (TM) wave. A Y-shaped light splitter is designed and simulated...
This paper presents finite difference time domain (FDTD) method for property analysis of waveguide loaded artificial circular dielectric resonator with anisotropic permittivity. The property of artificial circular dielectric resonator emphasized on the analysis is the resonant frequency of some resonance mode which is affected by its anisotropic permittivity. The FDTD method used for the analysis...
Recently, plasmonic metamaterial absorbers (MMAs) have attracted a surge of interest owing to its perfect performance. Metal-dielectric-metal structures combined with graphene show promising potential in nanoelectronics and nanophotonics applications such as photodetectors and optical modulators. However, the accuracy and efficiency of numerical approaches is a critical aspect of graphene-based nanoscale...
Forward-Backward Time-Stepping Method (FBTS method) is a technique to solve time domain inverse scattering problem. An incident pulse is radiated to unknown object. The scattering wave is measured at M points. A similar measurement is carried out at N different incident points. Total number of measured data is M × N. In FBTS method, the estimated field is calculated by FDTD method. The number of calculation...
In this paper, the hybrid implicit-explicit finite-difference time-domain (HIE-FDTD) method is proposed for efficient simulation of graphene-based frequency selective surfaces (GFSS) at Terahertz band, with the Drude model of monolayer graphene and associated auxiliary differential equation (ADE) technique implemented into the numerical methods for solving the Maxwell's equations. Numerical simulations...
The analyses and applications of memristor have attracted much interest recently due to its widespread potentials in nanoelectronics as memory devices, computer logics and other nanoscale devices. Circuit analyses and simulations involving memristor have been relied mainly on its SPICE model, while full-wave electromagnetic (EM) modeling of memristor is still generally lacking. The finite-difference...
Verification & Validation (V&V) attract more and more interests now and are extensively used in computational electromagnetics. In this paper, the method of exact solutions (MES) which is important in code verification is introduced by explaining the flow chartand the important glossaries and concepts of this method are explicated too. The process of global error evaluating by the approach...
The second-order of approximation numerical method for solution of Maxwell Equations in nondispersive medium, called FDTD (Finite-Difference Time-Domain), also known as Yee algorithm, was used to create the software package for modelling of electromagnetic waves propagation in medium (with the Courant stability condition). The Total Field/Scattered Field (TFSF) source is considered in detail. Inhomogeneous...
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