Re: IE3D Cell Accuracy
Hi, Plasma:
Implementing an adaptive meshing scheme is not difficult to us. There are a few reasons why we have not implemented it: (1) MOM is the most stable algorithm. Normally, when we follow the rules (appropriate meshing size with appropriate edge cells), we should get very good results. (2) The computational effort of MOM normally increases faster than FEM with increased meshing density. Adaptive meshing scheme may increase the meshing density substantially. It may reach the limit much faster than FEM. (3) Ansoft had an MOM code called Strata many years ago. They claimed they had adaptive meshing. Some IE3D customers asked me for it. I told them the same thing about the (1) and (2). I am not sure the adaptive meshing in Strata is good or not good. At least, the Strata code had disappeared from market.
On the IE3D 11, we have implemented a new meshng program "Contemporary Meshing". It can reduce the number of unknowns and make the cells more uniform to avoid numerical sigularity especially for general shaped strutures when AEC is applied. The new meshing also allows multiple layers of AEC (for single pass design of 40 dB couplers requested by customers), AEC on thick traces with enhanced accuracy (requested by customers), meshing alighment between closed coupled plates and traces (automating the process for high accuracy simulation of MIM capacitors and structures with finite dielectrics). I think we will consider implementing adaptive meshing in the next revision. Again, implementing it is not difficult. The quesiton is how much it can benefit the users. We are considering some other advanced meshing features may be even more helpful to users. I think we understand what the users need. By the way, please stay tuned. The IE3D 11 should be released in this month, and it has much features. New meshing scheme is only one of the major features. Other major features are (1) distributed EM simulation in mixed Windows and Linux environment. (2) IE3D engine seamlessly integrated into MWO 2004 of AWR. (3) Formula based geometry modeling with easy tuning and EM optimization; (4) Simulation of mixed inifinite substrates and finite dielectircs; (5) Much simplified procedure to create multi-layer structuers with BGA and wire bonds from GDSII and DXF file formats. Future extension will allow users to fully automate the process from GDSII (or other formats) to IE3D full-wave simulations. Thank you very much.