I have a design with Momentum blocks incorporated inside (as 'mom' blocks). All Momentum blocks are simulated up to 300GHz.
However, when running harmonic balance simulation, I get an error: "Can not enforce causality of S parameter for assigned 'fmax' value is equal to or less than the maximal frequency in...." where the rest is the path to the mommdl/text.txt file of the momentum cell view.
The maximal frequency of the HB simulation (100GHz) is far lower than the upprer simulated Momentum frequency (300GHz).
Any ideas on how to solve the problem?
Sorry, I wasn't sure whether the field was editable - I'll explain how I fixed it when I saw this in person.
In the CIW, use Tools->CDF->Edit CDF, and set the CDF type to "Base". Then pick the lib/cell of the Momentum generated block, and then you'll see all the parameters for the cell, including ImpMaxFreq. Change this to 3 times the value, and OK the form.