Mengtao Yuan

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In this paper, a numerical method to obtain an unconditionally stable solution of the time domain electric field integral equation for arbitrary conducting thin wires is presented. The time-domain electric field integral equation (TD-EFIE) technique has been employed to analyze electromagnetic scattering and radiation problems from thin wire structures.(More)
Sommerfeld integration is introduced to calculate the spatial-domain Green's functions (GF) for the method of moments in multilayered media. To avoid time-consuming numerical integration, the discrete complex image method (DCIM) was introduced by approximating the spectral-domain GF by a sum of exponentials. However, traditional DCIM is not accurate in the(More)
Broadband characterization of any electromagnetic (EM) data (e.g., surface currents, radiation pattern, and network parameters) can be carried out using partial information in the time domain (TD) and the frequency domain (FD). In this hybrid TD-FD approach, one generates the early time response using a TD code at a spatial location and uses a FD code to(More)
An improved testing procedure using the marching-on-in-order method to solve the time-domain electric field integral equation (TD-EFIE) for conducting objects using the Laguerre polynomials is presented. Exact temporal testing is performed before the spatial testing, therefore the retarded terms composed of the spatial and the temporal variables can be(More)
The traditional discrete complex image method (DCIM) is not efficient when the source and field points are in different layers because all the spatial coordinates can not be analytically included in the image terms in spatial domain. A two dimensional method (2D-DCIM) is introduced in this paper. In the new methodology we reorganize the spectral kernel as a(More)
In this paper, we provide three direct procedures to extrapolate the early-time and the low-frequency response of a causal signal simultaneously in the time-and frequency domain. Compared with the extrapolation by orthonormal basis functions, direct extrapolation is straightforward and we do not need to evaluate the basis functions and search for the(More)
In this paper we provide two direct procedures to extrapolate the early-time and the low-frequency response of a causal signal simultaneously in the time and frequency domain. We show that the extrapolation introduced by Adve and Sarkar (1998) is equivalent to a Neumann-series solution of an integral equation of the second kind. It is further shown that(More)
Extrapolation of wide-band response using early-time and low-frequency data has been accomplished by the use of the orthogonal polynomials, such as Laguerre polynomials, Hermite polynomials, and Bessel-Chebyshev functions. It is a good approach to reduce the computational loads and obtain stable results for computation intensive electromagnetic analysis.(More)
This paper proposes an enhanced DCIM without any quasi-static or surface-wave terms extracted. A novel path is chosen to obtain sufficient information of both the singularities and the trend of the spectral domain GF to infinity. Hence the discrete complex images (DCIs), which were supposed to approximate the spatial domain GFs only in medium distance(More)
Limitations of current numerical techniques have been outlined. The objective of this article is to point out that these statements of limitations may be applicable for the methodologies like FEM, FDTD and the hybrid MOM technique that the author has considered. Indeed, for such techniques even an analysis of a single Vivaldi element is a formidable(More)