Recently, Ansys released its HFSS Mesh Fusion product for simulation of complex EM systems. Signal Integrity Journal (SIJ) followed up with Dr. Matthew Commens, Principal Product Manager, HF at Ansys, Inc., to find out some more details. (You can see the original product news and background here.) The conversation has been edited for brevity below.
SIJ: Tell us about the idea for HFSS Mesh Fusion, how did it come about?
Matthew Commens (MC): Driven by emerging technologies like 5G and automated driving, these technologies’ higher data rates and frequencies plus tighter form factors mean system design via discrete component modeling can miss critical component-to-component electromagnetic EM coupling that could be ignored in previous technologies.
A need for “system-EM” simulation arose where engineers needed to understand EM coupling between components such as an IC to package, or a PCB with connector and cable or, at a larger scale, a Ku band satellite antenna array on an aircraft. Such simulation could be executed prior to HFSS Mesh Fusion, however due to the complexity of the system CAD, as well as the potential order of magnitude range in geometry scale for the system, generating a finite element mesh (FEM) could be very challenging.
As for optimal meshing technology, it turns out different approaches to meshing can work better in one CAD type vs. another. An example of “CAD specific meshing” is for laminate structures such as PCBs, ICs and IC packaging in which the upfront knowledge of how these components are designed as stacked 2D layers can speed up and enhance the meshing effort.
Prior to HFSS Mesh Fusion, it was a one-mesh-fits-all paradigm, and in an EM system with a mix of CAD types, generating the mesh could pose a challenge. But with HFSS Mesh Fusion, the right type of meshing technology can be applied locally to a component. So, for example, in the PCB with connector and cable example, a specific meshing algorithm can be applied to each to optimally address their respective and unique CAD types.
To understand the parallelization aspect, it helps to understand that with HFSS Mesh Fusion, the components of the system are initially meshed independently then merged together via the solver for an uncompromised, fully coupled EM solution. It is the independent, initial mesh generation that can leverage HPC and cloud resources. Downstream, the HFSS solver leverages multiple cores, processors, and nodes to solve a fully coupled EM system, including adaptive meshing for accuracy, with its standard HPC technology.
This customer example (pictured above) in particular was a touch panel display composed of many thin layers of dielectrics and conductors comprising the capacitive sensors array of the touch panel. The simulation was performed with the touch panel inside the TV housing plus the external EMI test antenna all inside a model of an anechoic EMI/EMC testing chamber. Without HFSS Mesh Fusion, solving this problem was essentially impossible as an initial mesh could not be generated. With HFSS Mesh Fusion, the first simulation ended in success. So, in effect, the time saving was infinite and this highlights how HFSS Mesh Fusion will make it possible to simulate what was thought impossible before.