Time-domain simulation of linear, frequency-dependent distributed networks using SPICE2

It is shown that although the general-purpose circuit simulation program, SPICE2, does not directly provide for time-domain simulation of linear, frequency-dependent distributed networks, it can be used indirectly for this task. Networks containing linear lumped elements and frequency-dependent transmission line elements, such as coaxial cable and microstrip line, can be analyzed. Since such a network can only be analyzed in the frequency domain, the method presented uses the frequency-domain simulation capabilities of SPICE2 to compute the network´s response to a truncated Fourier series representation of its periodic time-domain stimulus. The inverse Fourier series is used to obtain the resultant time-domain response. The method is applied to the analysis of high-speed digital computer networks. Measured and computed results are compared, showing that the method provides good accuracy if linearity can be assumed