TRANSIENT RESPONSE CHARACTERIZATION OF THE HIGH-SPEED INTERCONNECTION RLCG-MODEL FOR THE SIGNAL INTEGRITY ANALYSIS

Abstract

This paper is devoted on the characterization method of RF/digital PCB interconnections for the prediction of the high- speed signal transient responses. The introduced method is based on the use of the interconnection line RLCG-model. Theoretical formulae enabling the extraction of the electrical per-unit length parameters R, L, C and G in function of the interconnection line physical characteristics (width, length, metal conductivity, dielectric permittivity ...) are established. Then, by considering the second order approximation of the interconnection RLCG-model transfer matrix, the calculation process of the transient responses from the interconnection system transfer function is originally established. To demonstrate the relevance of the proposed model, microwave- digital interconnection structure comprised of millimetre microstrip line driven and loaded by logic gates which are respectively modelled by their input and output impedances was considered. Then, comparisons between the SPICE-computation results and those obtained from the proposed analytical model implemented in Matlab were made. As results, by considering a periodical square microwave-digital excitation signal with 2Gbits/s rate, transient responses which are very well- correlated to the SPICE-results and showing the degradation of the tested signal fldelity are observed. The numerical computations conflrm that the proposed modelling method enables also to evaluate accurately the transient signal parameters as the rise-/fall-times and the 50% propagation delay in very less computation time. For this reason, this analytical-numerical modelling method is potentially interesting for the analysis of the signal integrity which propagates