along the -direction, 13 subdivisions along the -direction, and five subdivisions along the z-direction. The -directed current is depicted in Figure 5. Here, agreement with the frequency domain data is very good.For the last example, we consider a PEC cone with base radius 0.25 m and height 1.0 m from the center of the base disk to the apex, as shown in Figure 6. The surface is made of 252 triangular patches and 378 common edges. The result for the surface current at (0.0, 0.1964, 0.2143) is shown in Figure 7. Agreement between the results from the proposed method and the IDFT is very good. CONCLUSIONAn unconditionally stable solution for the time-domain MFIE algorithm was proposed for three-dimensional arbitrarily closed PEC structures. To model arbitrarily shaped structures, triangular patch modeling was employed to provide more flexibility. We utilized a marching-on-in-order method to solve the TD-MFIE with weighted Laguerre polynomials. As an entire domain temporal basis and for testing, the advantages of using the weighted Laguerre polynomials are: (1) it guarantees late time stability; (2) the solution is independent of the time discretization; (3) temporal derivatives can be treated analytically, and (4) most importantly, from a computational standpoint, the spatial and temporal variables can be separated, resulting in an efficient and accurate solution. Transient electric currents obtained by the present method are unconditionally stable. Moreover, agreement between the results obtained using the proposed method and the IDFT of the frequency domain is very good. proposed a method to extract steady-state thermal resistance, which is based on the variation of the temperature-dependent ␤ or V BE . It requires the DC I-V measurements of at least two temperatures. Bovolon et al. [3] presented an alternate approach of determining thermal resistance using various operating points. Another method needs to control the substrate temperature using thermal chuck [4]. In [5], an elegant method is described to extract the thermal resistance requiring only the DC I-V curves at room temperature. However, it still needs to determine two DC model parameters beforehand. In this paper, we present a method to extract the thermal resistance using only the DC I-V characteristics measured at room temperature. For a reliable extraction of thermal resistance, only one model parameter has to be determined. This method is simple and robust, and it can produce accurate thermal resistance that is comparable to conventional methods [3][4][5]. The thermal resistance values calculated using our method are verified by extensive measurements on a variety of BJT/HBT devices. EXTRACTION METHODFor the bipolar transistor, the increased in DC device temperature is solely determined by the thermal resistance and power dissipation. Mathematically, this is expressed as follows:where ⌬T is temperature rise for the base-collector (BC) junction, R th is thermal resistance, and ⌬P diss is dissipation power. As a first-order approximation, one can as...

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Absrrucf-Formulas for the potentials due to uniform and linearly varying source distributions defined on simply shaped domains are SYStematically developed and presented. Domains considered are infinite planar strips, infinite cylinders of polygonal cross sections, planar surfaces with polygonal boundaries, and volumetric regions with polyhedral boundaries. The expressions obtained are compact in form and their application in the numerical solution of electromagnetics problems by the method of moments is illustrated.

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Equivalentsurface currents obtained from