Electromagnetic emissions from electronics associated with explosives is a potential detection modality, both passive listening, and stimulated RF emissions. However, the parasitic paths by which energy is coupled off...
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ISBN:
(纸本)0819440892
Electromagnetic emissions from electronics associated with explosives is a potential detection modality, both passive listening, and stimulated RF emissions. However, the parasitic paths by which energy is coupled off a printed circuit board from an active device, and by which external energy can be coupled onto the board and to a device, must be identified and characterized. One such noise-coupling path is identified in this work, and a modeling approach demonstrated. In particular, coupling of noise from the DC power bus of a multilayer printed circuit board that uses entire metal layers for power and ground, and an I/O line that transitions through the DC power planes is investigated.
In this paper, we present a finite-differencetime-domain technique for determining the resonance frequencies of microwave components by deriving the standing-wave patterns rather than simulating the scattering parame...
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In this paper, we present a finite-differencetime-domain technique for determining the resonance frequencies of microwave components by deriving the standing-wave patterns rather than simulating the scattering parameter spectra of the component. We show that, compared to the S-parameter spectra simulation technique, the technique proposed herein can save the time needed to compute the resonant frequencies by an order of magnitude. (C) 2001 John Wiley & Sons, Inc.
Recently, various researches on optical recording based on near-field optical principles have been conducted for higher data storage density. However, there is a problem of the trade-off between signal output and spat...
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Recently, various researches on optical recording based on near-field optical principles have been conducted for higher data storage density. However, there is a problem of the trade-off between signal output and spatial resolution, especially when an aperture-type near-field optical head is utilized for high speed data-readout. In order to solve this problem, we propose a novel near-field optical head, the planar aperture-mounted head with a minute scatterer. and analyze its read-out performance through the three-dimensional finite-differencetime-domain (3D-FDTD) method. Our simulations reveal that the Silver scatterer placed at the center of the planar aperture strongly enhances optical energy due to the local surface plasmon excitation, and that this head has the potential to realize high resolution and high signal output simultaneously.
The finite-differencetime-domain (FDTD) field simulations have been employed to visualize standing-wave patterns in single-layer, rectangular, planar capacitors and capacitor chips. These patterns are used for the an...
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The finite-differencetime-domain (FDTD) field simulations have been employed to visualize standing-wave patterns in single-layer, rectangular, planar capacitors and capacitor chips. These patterns are used for the analysis of the resonant mode types, and for the determination of the resonance frequencies. The results of simulation are experimentally verified by measuring the S-parameter spectra. In addition, we show that the dimensions of the capacitor plates can be optimized in order to maximize the first resonant frequency of the capacitor, rendering it useful for high-frequency applications. (C) 2001 John Wiley & Sons, Inc.
We have numerically calculated attenuated total reflection (ATR) signals due to two-dimensionally ordered (2D) spheres on a glass substrate for both TE- and TM-polarized incident light beams using a finitedifference ...
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We have numerically calculated attenuated total reflection (ATR) signals due to two-dimensionally ordered (2D) spheres on a glass substrate for both TE- and TM-polarized incident light beams using a finitedifferencetime-domainmethod. The calculated ATR spectra are in good agreement with the experimental ones reported previously by Lis. From the ATR spectra and the spatial distribution of light intensity, it has been found that the ATR dips are due to the excitation of the optical modes in the 2D spheres. The propagation length of the optical modes is confirmed to be comparable to the diameter of the sphere. It indicates that the optical modes propagate in a variety of fashions and the light intensity in the 2D spheres takes a maximum value at the contact points between the spheres.
This paper shows how the dielectric constant of alumina and rutile substrates at microwave frequencies can be accurately determined by fitting the simulated S-parameter spectra of microstrip ring resonators, generated...
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This paper shows how the dielectric constant of alumina and rutile substrates at microwave frequencies can be accurately determined by fitting the simulated S-parameter spectra of microstrip ring resonators, generated via the finite-differencetime-domain (FDTD) method, to experimentally measured data. The proposed method does not require the determination of the effective dielectric constant and the approximate closed-form expressions to find the true permittivity of the substrate. This is essential for the characterization of high-K dielectric materials at high frequencies when the closed-form expressions are invalid. (C) 2001 John Wiley & Sons, Inc.
This paper describes EM Wave Simulation, a windows-based animated electromagnetic wave simulation package, developed as a supplementary tool for teaching electromagnetic field theory at the undergraduate level, For th...
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This paper describes EM Wave Simulation, a windows-based animated electromagnetic wave simulation package, developed as a supplementary tool for teaching electromagnetic field theory at the undergraduate level, For the purpose of rapid display of electromagnetic wave images, the implemented algorithm assumes a structure sandwiched between two perfect electric conductor planes and employs a 2(1)/(2)-dimensional finite-differencetime-domain (FDTD) method on a staggered grid, which is suitable for simulating simplified electromagnetic wave propagation in indoor environments. Frequency-domain spectral information can be extracted with the built-in one- and two-dimensional discrete Fourier transforms facilities. A user-friendly mouse-and-menu-driven interface allows user to set up simulations containing complex geometries in a straightforward fashion. Simulated results, in both time and frequency domains, can be displayed in real-time on the computer screen, which makes the application ideal for use in interactive undergraduate teaching. Some sample simulations are discussed in the paper to illustrate its principal functionality. (C) 2002 Wiley Periodicals, Inc.
Validations of the accuracy of the FDTD method for near-field simulations are critical at this time to assess the accuracy of the FDTD method for the simulation of personal communication devices. Excellent comparisons...
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Scattering parameter results for various types of microstrip circuit configurations have been calculated using a full-wave electromagnetic solution technique. A full-wave electromagnetic solution technique is the most...
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This paper presents a general group of formulas by a combination of conformal mapping and 2-D FDTD (CF–FDTD). By this new method, the cutoff wavenumbers and dispersive characteristics of higher order TE modes in an e...
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