Characterizing the cylindrical via discontinuity

It is demonstrated that the nonorthogonal finite-difference-time-domain (FDTD) technique can handle cylindrical via discontinuities without the use of an excessive number of unknowns as would be required with an equivalent orthogonal FDTD approach. Since the FDTD analysis is bandlimited in the frequency domain, the inaccurate, high-frequency components need to be removed before performing reliable transient analyses with the numerical results. The use of window filters to solve this problem is discussed, and a Hanning window is employed in a study of the transient response of an equivalent circuit for the via.<>