Monte Carlo simulations of microstrip lines with random substrate impurity

Monte Carlo simulations of microstrip lines with random substrate impurity are performed. Each realization of current distribution on the microstrip l ine with substrate impurity is calculated by the hybrid finite element meth od/multilevel fast multipole algorithm. After taking the ensemble average o f all the realizations, the super-resolution estimation of signal parameter s via rotational invariance technique algorithm is employed to extract the characteristic parameters of the transmission line from the current distrib ution. Comparisons of our numerical results and previously published result s for the conventional microstrip line with homogeneous substrate confirm t he validity, accuracy, and efficiency of our simulation tool. Our Monte Car lo simulations demonstrate that the effect of substrate impurity on the cha racteristics of a microstrip line can be quite accurately estimated by repl acing the inhomogeneous substrate with a homogeneous one whose dielectric c onstant is the averaged value for different materials weighted by their vol ume ratios. This simple estimation approach, however, does not apply to the attenuation constant of the line due to the effect of finite substrate wid th. (C) 2001 John Wiley sr Sons, Inc.