System Analysis of High Speed Designs with Strong Nonlinearity

High speed designs often involve transistors operating in linear region, transmission lines, voltage regulator, and other passive electromagnetic (EM) components. Therefore, linear time invariant (LTI) assumption has been prevalent in system analysis for decades. However, ever-increasing signal speed and lower power, area budget are pushing designs to strong nonlinear regimes, e.g., re-drivers (contain limiting amplifiers) have to be used to compensate for the high frequency channel loss. The nonlinear effect is further amplified when the signal is travelling across different physical mediums, resulting in multi-dimensional interaction among transistors, package, motherboard, and external devices. Such nonlinear effects deteriorate system analysis, especially for coupling between device and field. In this paper, we will present system analysis flow and a new approach to fast and accurately simulate such nonlinear high speed designs.