Abstract: In this paper, a numerical method based on weighted Laguerre polynomials finite-difference time-domain (WLP-FDTD) is proposed to analyze noise propagating problem in power/ground planes with narrow slots. Firstly, the planes are divided into two parts, one is the planes, and the other is the slots. Then the planes are modeled as 2D equivalent circuit networks and the slots are modeled as coupled circuits. Finally, the equivalent 2D circuits are solved by WLP-FDTD. Numerical results show that the WLP-FDTD-based method can achieve higher efficiency than the traditional finite-difference time-domain method but the accuracies are the same. Therefore, the proposed WLP-FDTD-based method is suitable for accurate and efficient analysis of noise propagating on power/ground planes in high-speed circuits.

Key words: power/ground planes with slots, equivalent circuits, weighted Laguerre polynomials finite-difference time-domain (WLP-FDTD)