Line width optimization for interdigitated power/ground networks

Abstract

Higher operating frequencies have increased the importance of inductance in power and ground networks. The effective inductance of the power and ground network can be reduced with an interdigitated structure. A closed-form solution for determining the optimal power and ground wire width is described, producing the minimum impedance within an interdigitated structure. The optimal wire width is determined under different physical network dimensions and signal frequencies, suggesting useful trends for interdigitated power and ground networks. In addition, a closed-form expression for the optimal wire width is determined that minimizes the voltage drop over a single metal layer of an interdigitated power/ground network.