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In t h i s p a p e r, t h r e e -d i m e n s i o n a l full wave analysis of tapered microstrip lines is carried out in the time domain. The method used is the conformal grids FD-TD method. Computed results are compared with experimental ones and those obtained by the finite element method. The results agree well. As a result, it is shown that the propagation c h a r a c t e r i s t i c s a r e v e r y d i f f e r e n t from t h o s e obtained through two-dimensional modeling.

Recently, malfunctions by crosstalk between signal lines have become a problem in an electronic circuit which has been more densely organized and handles signals at higher frequencies. To prevent malfunctions due to these noises, it is important to find the relationship of the crosstalk with the materials and structures of the circuit board. Especially, as the density is increased, the use of multilayered configuration is increased so that the understanding of the crosstalk between interconnects arranged in a three‐dimensional fashion is increasingly more important. Usually, the analysis of crosstalk has been carried out by means of the equivalent circuit analysis. It is not easy to adjust the number of discretizations and the analysis between the three‐dimensional (3‐D) interconnects. In reference to the foregoing, this paper describes a crosstalk analysis between parallel microstrips by means of the finite‐difference time‐domain (FD‐TD) method which, among the 3‐D electromagnetic field analysis methods, requires small memory and computational time. Good agreement is confirmed between the thoretical and experimental results on the crosstalk waveforms and the crosstalk coefficient. Hence, the effectiveness of the FD‐TD method for the crosstalk analysis has been confirmed. It is believed that the FD‐TD method is extremely effective for analysis in the circuit design.

Prediction of the mutual effects of the components involving through holes is essential for the design of multilayer circuits to operate at high frequencies. In this article, the characteristics of coupling between adjacent pairs of through holes and between a through hole and microstrip were analyzed using the finite-difference time-domain (FD-TD) method. Numerical results in the time and frequency domains were compared with experimental results; these agreed well. Coupling coefficients were shown to depend on the orientation and distance of the microstrips or a through hole of the secondary from the primary through hole. The distribution of electric field intensity during through hole-through hole coupling was also shown. The method described appears to hold great promise for substitution for the experimental process. D

With the recent rapid advance in electronic technology, electronic components have become smaller, lighter and higher in performance. In connection with this trend, there has been increased use of the high frequencies due to increased speed of the devices. Under such situations, the interconnects between the electronic devices must be treated as strip lines. Especially, the through‐hole with a three‐dimensional structure indispensable for high‐density interconnects has nonnegligible effects on the circuits. Hence, the need for an analysis of its characteristics is acute. In this paper, to derive quantitative propagation characteristics of the through‐hole, a three‐dimensional electromagnetic field simulation of such a structure was carried out using the spatial network method and the results were compared with experimental data. It was confirmed that the simulated values of the time domain response and the frequency characteristics showed good quantitative agreement with the measured data. As a result, the validity of the simulation and the basic propagation characteristics of a through‐hole were confirmed.