So what does it mean to turn signal integrity simulation inside out? Modern simulation has physics-based solvers in the foreground supported by circuit and system simulation rather than the other way around. All electronic design is fundamentally based on Maxwell’s equations, so naturally the most rigorous way to deliver accurate simulation of high-performance systems is to solve those equations directly. In the past, electronics were not dense enough or fast enough to require solutions of the fully coupled Maxwell equations (what we call “full-wave” field solutions), nor did we have the computers able to solve these giant problems. Traditional electronic design validation relied mainly on circuit simulators like SPICE. Only isolated portions of the design were modeled using electromagnetics. Electrical parasitics were typically extracted using approximate, quasi-static table look-up methods. We worked with circuit simulation, quasi-static solutions and hybrid methods for signal integrity design.
ANSYS is pursuing a strategy in which electromagnetic simulation is primary and circuit analysis supports the electromagnetic solution, rather than the other way around. To achieve this goal, we have added new software features that enable engineers to perform transient circuit analysis directly from the layout in ANSYS HFSS and ANSYS SIwave. The ANSYS strategy is to solve “Big EM” systems using ANSYS HFSS and ANSYS SIwave full-wave electromagnetic field solvers. The isolated nonlinear driver and receiver circuits are solved by circuit simulation with accurate, full-wave models of the interconnect. Thus the physics is primary, and circuits are secondary. That is what is meant by “inside-out.” This new era permits circuit and system analysis to be part of the broader physics-based assembly solution. By relying on our layout solution we can automate much of the process.
High-Performance Computing
A major enabler for turning SI simulation inside out is advanced high-performance computing. With the right numerical procedures and algorithms, it is possible to take advantage of large compute clusters to accelerate solutions, solve bigger problems, and sweep frequencies and parameters. HPC opens up the possibility of optimizing a design and improving its reliability by making 3-D full-wave simulations of many design variations both practical and efficient.
One of the newest technologies is distributed adaptive meshing. This is the most fundamental change to the adaptive process ever since HFSS was initially released. HFSS has always used a central, user-defined frequency for the adaptive solution, followed by various frequency sweep methods to get a broadband response. The frequency sweep methods used the adapted and converged mesh from that single frequency to compute the system response at all other frequencies.
ANSYS Pervasive Engineering Simulation
If you’ve ever seen a rocket launch, flown on an airplane, driven a car, used a computer, touched a mobile device, crossed a bridge or put on wearable technology, chances are you’ve used a product where ANSYS software played a critical role in its creation. ANSYS is the global leader in engineering simulation. We help the world’s most innovative companies deliver radically better products to their customers. By offering the best and broadest portfolio of engineering simulation software, we help them solve the most complex design challenges and engineer products limited only by imagination.
