Measurement-based line parameter extraction method for multiple-coupled lines in printed circuit boards

Abstract

This paper proposes a novel extraction method of line parameters for multi-coupled lines on high-speed and high-density PCBs, where it uses TDR measurement in time domain and S-parameter measurement in frequency domain. The accuracy of the proposed method have been verified experimentally by comparing the crosstalk noise in the time domain, where (1) the proposed method extracts RLGC matrices by measuring the test pattern, (2) the crosstalk noise is obtained through SPICE simulation using the extracted RLGC matrices and (3) the SPICE-simulated crosstalk noise is compared with he measured crosstalk noise. From the crosstalk noise comparison, the proposed method is proven to be very accurate. For N-coupled lines, the proposed method doesn't require expensive 2N-port probe for N-coupled lines but only two-port probe, which provides a simple, accurate, and economic extraction method of line parameters for multi-coupled line on the PCB. In the early stage of PCB design, the proposed method is very useful, because it extracts accurate interconnection parameters of each test board and enables to compensate various side effects due to the variation of PCB fabrication process. Also, the proposed method is necessary to analyze the signal integrity of future high-density and high-speed digital system on PCBs.