In indoor cellular coverage planning, a lift shaft and the associated lift car create one of the most difficult propagation environments. In this paper, wave propagation in such a shaft is studied by modeling the exci...
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A discretized version of Poynting's theorem is rigorously derived from the standard FDTD equations. By using the correct averaging expressions for the Poynting vector itself the energy density and the current powe...
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A discretized version of Poynting's theorem is rigorously derived from the standard FDTD equations. By using the correct averaging expressions for the Poynting vector itself the energy density and the current power density, the well-known form of the theorem in continuous space is obtained. The theorem is checked by calculating the radiated power of an antenna in two ways. It is also shown that the use of nonstandard FDTD equations for thin wires violates the theorem. (C) 1995 John Wiley & Sons, Inc.
This letter describes a method intended for the resolution of the electromagnetic diffraction of structures of very different sizes. The problem to be solved is divided into two subdomains: the first where a ''...
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This letter describes a method intended for the resolution of the electromagnetic diffraction of structures of very different sizes. The problem to be solved is divided into two subdomains: the first where a ''rigorous'' method analyzes the radiation of small elements, and the second where an ''asymptotic'' method analyzes the diffraction on the edges of large elements. (C) John Wiley & Sons, Inc.
The finite-differencetime-domain (FDTD) method is used to analyze the electromagnetic compatibility and interference (EMC and EMI) problems doe to the electromagnetic radiation from a video output amplifier located i...
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The finite-differencetime-domain (FDTD) method is used to analyze the electromagnetic compatibility and interference (EMC and EMI) problems doe to the electromagnetic radiation from a video output amplifier located inside a computer monitor. The multiple grid technique is implemented in the FDTD method to improve the computational efficiency. The video output amplifier is modeled by a rectangular iron container with an equivalent dipole antenna located at the center of one opened wall faced to the cathode-ray-tube (CRT). The coupled electric fields inside and outside the monitor are calculated. It is found that higher values of coupled electric fields occur near the monitor screen. It Is also found that the coupled electric fields outside the CRT region drop sharply in amplitude. Simulation results of coupled electric fields at a distance of 3 m from the monitor screen also comply with the FCC regulations. Calculation results also agree with the experimental data for coupled electric fields outside the monitor screen at a measured distance of 3 m.
The influence of ground terminal shape on the resonant frequency of a microstrip resonator is investigated through numerical simulations and experiments, Resonators are one of the basic components of very small high-d...
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The influence of ground terminal shape on the resonant frequency of a microstrip resonator is investigated through numerical simulations and experiments, Resonators are one of the basic components of very small high-dielectric stripline filters, named the laminated planar filter. The resonant frequencies are calculated by means of the finite-differencetime-domain (FDTD) method and compared with experimental results, It is also shown that the resonant frequency is directly related to the square root of its line inductance when the resonator is regarded equivalently as a series LC circuit.
A general algorithm for including large-signal active three-terminal models into the finite-differencetime-domain (FDTD) method is presented. A dynamic interface between the active device and the FDTD lattice is used...
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A general algorithm for including large-signal active three-terminal models into the finite-differencetime-domain (FDTD) method is presented. A dynamic interface between the active device and the FDTD lattice is used to simulate the prominent nonlinear time-dependant behavior of the three-terminal active device, which is connected across multiple FDTD cells. A technique for introducing an internal electromagnetic (EM) field absorber into the FDTD three-terminal active device model in order to eliminate undesired current coupling is discussed. Numerical comparison shows this method is accurate and expected to have general utility for other complicated hybrid lumped-circuit FDTD modeling situations.
Using the finite-differencetime-domain technique (FDTD), the scattering patterns from cells and organelles of arbitrary shape can be computed. With this method Maxwell's curl equations are discretized in space an...
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ISBN:
(纸本)0819423904
Using the finite-differencetime-domain technique (FDTD), the scattering patterns from cells and organelles of arbitrary shape can be computed. With this method Maxwell's curl equations are discretized in space and time and the electric and magnetic fields are computed at all points within and around the cell. The cell is constructed as a dielectric object and the far-field scattering pattern, containing both amplitude and direction information is computed. Results are presented for three-dimensional cells containing different combinations of organelles, such as nucleus, cytoplasm, and mitochondria, to assess the effect of each on the scattering pattern. The computed scattering patterns indicate that small organelles such as mitochondria play an important role in scattering from cells and variations in the refractive index of the nucleus also affect the scattering characteristics.
A hybrid finite-difference-time-domain/angular spectrum propagation modeling technique and a finite-difference thermal model are used to study near-field optical and two-photon absorption data storage systems. The ele...
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ISBN:
(纸本)0819425303
A hybrid finite-difference-time-domain/angular spectrum propagation modeling technique and a finite-difference thermal model are used to study near-field optical and two-photon absorption data storage systems. The electromagnetic model is used to analyze scattering effects in structures where scalar-based theory is not appropriate. The thermal model is used in a near-field magneto optic data storage system to calculate data mark sizes.
A new method of S-parameter extraction from the FDTD in analyses of microstrip circuits is proposed It only uses the Ex-field component parts in three selected transverse cross sections of the transmission line under ...
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A new method of S-parameter extraction from the FDTD in analyses of microstrip circuits is proposed It only uses the Ex-field component parts in three selected transverse cross sections of the transmission line under approach. The reflection coefficient is extracted from a single run of the FDTD. Neither prior knowledge of the line nor any computation of the derivative of the electric and magnetic fields is needed. The proposed new method is directly applicable to analyses of the discontinuities of microwave transmission circuits. (C) 1997 John Wiley & Sons, Inc.
The absorbing performance and computational efficiency of an accurate and efficient absorbing boundary condition due to Liao are discussed and compared with Mur's ABC. Numerical simulations show that Liao's AB...
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The absorbing performance and computational efficiency of an accurate and efficient absorbing boundary condition due to Liao are discussed and compared with Mur's ABC. Numerical simulations show that Liao's ABC in general outperforms Mur's ABC. Furthermore, Liao's ABC provides greater flexibility and accuracy than Mur's ABC for arbitrary incidence. Based on the results of these computer simulations the relative performance, including their efficiencies, CPU, and memory requirements, are tabulated for easy reference. A selection guide for the weighting factor alpha in Liao's ABC for various incident angles is also given herein. Proper choice of alpha enables one to use ail ABC of lower order, this resulting in a savings in computational requirements. (C) 1997 John Wiley & Sons, Inc.
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