Simulating accurate VIA performance is one of the key to perform good multilayer board design for RF/uWave as well as High Speed Digital applications to maintain Signal Integrity.
Over the years designers tend to believe that only full 3D simulators i.e. FEM or FDTD based solvers can offer accurate simulations for multilayer VIA structures and complex 3D simulations are performed which can take up to several hours to simulate VIA structures causing increased turn around and design iterations.
With newer ADS releases it is now possible to simulate multilayer VIA structures accurately and efficiently using Method of Moments (MoM) i.e. ADS Momentum largely due newer algorithms which are incorporated in ADS to handle such geometries very accurately.
Also newer ADS release comes with a very nice utility to draw these multilayer VIAs pretty quickly and efficiently. Attached technical note offers step by step procedure to use the multilayer VIA utility to draw these kind of VIA structures and discusses simulation of multilayer VIA using Momentum & FEM solver which are fully integrated into ADS environment. Comparison of results using Momentum & FEM solvers are also provided.