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Edge mesh setting in Momentum

Question asked by anhchu_iis on Sep 29, 2020
Latest reply on Oct 5, 2020 by anhchu_iis

Dear all,


We are em simulating a slab inductor at 263GHz using Momentum and got confusing results from different settings for the edge mesh width. The inductor is a 7.5x45um aluminium trace with a thickness of 3um. At 263GHz, the skin depth is ~160nm. We created two edge ports p1 and n1 for the simulation (see part 1 of the figure). In the simulation setting (see part 2 of the figure), we fixed the mesh density and the TL Mesh and changed the edge mesh setting. For automatic setting, we got edge mesh with a width of 669nm and resistance of 0.672 Ohm. Being aware that this edge mesh may be too thick (thicker than the skin depth), we tried different value for the edge mesh width, from 1nm (very fine) to 100nm. You could see the change of the resistance and the current density. Noticeably, for finer edge mesh, the current does not flow on the two side walls of the trace, but rather inside. The resistance has a peak value for 10nm edge mesh width. Overall, the Q value of our slab inductor varies from about 25 to 55.


We are quite confused about what edge mesh width we should pick for the realistic loss of the trace. Could you provide some hints on this? 


Thank you a lot.