precomputation in MomentumAADS fails to work...

I want to run substrate precomputation in Momentum before I do S-parameter simulation. However, after running once precomputation with frequency range 10G to 20GHz, each time I want to set up a new precomputation with new frequencies, the software tells me "substrate exists for 10G to 20GHz" and can't function further. Without precomputation, I guess I can't get a correct simulation result. Does anybody here know how to solve the problem? it may be a simple problem, but I am a green hand to ADS. Thank you....

Hi,

i'm no expert either but I think you can skip the "precompute" and do the S-para simulation straight away. Reason being that the substrate properties for the freq range has already beem precomputed in the previous iteration.

Hope this works! Gd Luck!

"substrate precomputation" means Green's function computation. Green's function depends upon the frequency, the geometry and material parameters of the stratified media, but not on the metal trace. Apparently Momentum stores the computed value in your hard drive (cache) so it doesn't need to compute it again. It is a technique used in other solvers too.

Thanks to you two! According to your analysis, I tried the frequency out of the range of 10G to 20G, it could work again! Before that, though I changed to a new frequency, it was still in the range of 10G to 20G, so Momentum wouldn't compute it again. Thank you for helping me to know a simple but great knowledge.