ADAPTATION OF SPICE3 TO SIMULATION OF LOSSY MULTIPLE-COUPLED TRANSMISSION-LINES

Design of high-speed, high-proformance electronic circuits requires si mulation of transients in networks that include multiple, coupled loss y transmission lines. A widely used circuit simulator, SPICE, does not have facilities for simulation of multiconductor, transmission lines. Recently a modification to SPICE3 to include multi-conductor lossless lines was reported. In many situations line losses must be included i n the model and networks with lossy transmission simulated. In general simulation of lossy transmission lines is complex and computationally very intensive. The situation is simpler when D-C losses are consider ed. A recent study concluded that D-C losses provide an adequate model ing of signal transmission in many practical situations. This paper de scribes the implementation of multi-conductor, coupled lines with D-C losses in SPICE3e2. This implementation ties SPICE transient analysis with a special algorithm for the analysis of a transmission line and i s more efficient than another approach based on the concept of a trans mission line subcircuit. Internal tests of the new program, LSPICE3, w ere successfully performed and now this program is available to SPICE3 users.