March 26, 2012 -- Most high-speed printed-circuit-board (PCB) designers are familiar with simulating the performance of the laid-out and routed board. Still, one question pops up time and time again: "What can you simulate before you lay out the board?" This article will explain the differences between pre-layout and post-layout simulation, as well as answer the above question.

By Patrick Carrier. (Carrier is a technical marketing engineer for high-speed PCB analysis tools at Mentor Graphics Corp.)