The frequency characteristics of whole-body averaged specific absorption rates (SARs) in a human model exposed to a near field of an electric dipole or a magnetic dipole are calculated, using a finite-differencetime-...
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The frequency characteristics of whole-body averaged specific absorption rates (SARs) in a human model exposed to a near field of an electric dipole or a magnetic dipole are calculated, using a finite-difference time-domain method. The dependences of the characteristics on the orientation of the dipole and on the distance from the source to the model are investigated. It is shown that the resonant peak of the SAR that appears in the E-polarized far-field exposure is observed only when the source is E-polarized and is located at 80 cm, while the peak vanishes or is not noted when the source is located at 40 cm and 20 cm nor when it is H-polarized. The relationships between the whole-body averaged SARs and the incident electromagnetic field strengths are also investigated. It is suggested that the spatially-averaged value of the dominating component between the electric field and the magnetic field over the space where a human body would occupy provides a relevant measure to estimate the whole-body averaged SAR of a body in the vicinity of a small radiation source.
A finite-difference time-domain method incorporating perturbation techniques is used to calculate the Q factors of resonators with variable conductivities of conductor and dielectric. Several kinds of the resonators i...
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A finite-difference time-domain method incorporating perturbation techniques is used to calculate the Q factors of resonators with variable conductivities of conductor and dielectric. Several kinds of the resonators including empty cavities and a dielectric resonator are studied by this method. The numerical results are shown to be in excellent agreement with the rigorous theoretical solutions.
Slot narrow-wall couplers are simple but effective directional couplers. A simple and efficient approach to analyze these devices using the FDTD algorithm is presented. The technique uses a synthetic excitation and a ...
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Slot narrow-wall couplers are simple but effective directional couplers. A simple and efficient approach to analyze these devices using the FDTD algorithm is presented. The technique uses a synthetic excitation and a second-order ABC especially designed for the frequencies contained in the incident field. The method is illustrated in the computation of coupling and isolation of a two-slot - 20-dB coupler and is also applied to study a three-slot coupler. (C) 1994 John Wiley & Sons, Inc.
This Letter discusses the computation of scattering by thin lossy, nondispersive dielectrics using the finite-differencetime-domain (FD-TD) method. The time-domain relationship between the electric fields normal to a...
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This Letter discusses the computation of scattering by thin lossy, nondispersive dielectrics using the finite-differencetime-domain (FD-TD) method. The time-domain relationship between the electric fields normal to a lossy material boundary is used in a ''smart cell'' approach which allows the thickness of the dielectric to be less than the spatial grid size. These results are compared to the ''brute force'' FD-TD approach.
The radiation behavior of a microstrip traveling-wave antenna is theoretically analyzed using a time-domainmethod based on the FDTD. The time evolution of the fields and currents computed by the FDTD can be given in ...
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The radiation behavior of a microstrip traveling-wave antenna is theoretically analyzed using a time-domainmethod based on the FDTD. The time evolution of the fields and currents computed by the FDTD can be given in the frequency domain on a large bandwidth using Fourier transforms. Then it is possible to deduce classical parameters as the radiated field, the gain, and the power delivered by the antenna. (C) 1993 John Wiley & Sons, Inc.
In this article we apply the generalized eigenvalue method (GEM) to extract the complex exponentials from a truncated time record computed by the finite-differencetime-domain (FDTD) code for analyzing microwave integ...
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In this article we apply the generalized eigenvalue method (GEM) to extract the complex exponentials from a truncated time record computed by the finite-differencetime-domain (FDTD) code for analyzing microwave integrated circuits. To obtain accurate scattering parameters without further FD TD computations, the truncated FDTD time record is efficiently extended into the future by summing the complex exponentials with complex coefficients determined by the least-squares method. Numerical GEM results with fewer poles are shown to be in good agreement with those obtained by the Prony method with a large number of poles.
This paper discusses the fully three-dimensional finitedifferencetimedomain (FDTD) method to analyze a monopole antenna mounted on a rectangular conducting box covered with a layer of dielectric. The effects of the...
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This paper discusses the fully three-dimensional finitedifferencetimedomain (FDTD) method to analyze a monopole antenna mounted on a rectangular conducting box covered with a layer of dielectric. The effects of the conductivity and the permittivity of the dielectric layer are investigated. It is shown that all calculation results agree very well with the measured data.
In this article, the frequency-dependent finite-differencetime-domain (FD)2-TD technique is used to analyze a coaxial-line excited cylindrical cavity loaded with an electrically lossy dielectric, modeled by a first-o...
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In this article, the frequency-dependent finite-differencetime-domain (FD)2-TD technique is used to analyze a coaxial-line excited cylindrical cavity loaded with an electrically lossy dielectric, modeled by a first-order Debye expression. Results obtained for the reflected voltage in the coaxial line are Fourier transformed to yield the reflection coefficient GAMMA and input admittance at the coaxial aperture. Experimental measurements for GAMMA show good agreement with predicted (FD)2-TD results. (C) 1993 John Wiley & Sons, Inc.
This Letter discusses the computation of the scattering and radiation by thin wires with a nondispersive dielectric coating using the finite-difference time-domain method. A Fourier transform is then performed on the ...
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This Letter discusses the computation of the scattering and radiation by thin wires with a nondispersive dielectric coating using the finite-difference time-domain method. A Fourier transform is then performed on the time-domain results to obtain the scattering and antenna radiation patterns in the frequency domain.
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