Momentum is a 3-D planar electromagnetic (EM) simulator used for passive circuit analysis. It accepts arbitrary design geometries (including multi-layer structures) and accurately simulates complex EM effects including coupling and parasitics. Accurate EM simulation enables RF/MMIC designers to improve passive circuit performance and increases confidence that the manufactured product will function as simulated. Momentum RF is a second solver technology within the Momentum EM engine that reduces simulation time without sacrificing accuracy on large structures under a half wavelength. Because Momentum is an integrated component in the Advanced Design System (ADS) design flow, simulation setup times are reduced, and design productivity is increased.