When I cascade nports in spectre, all dc values become zero or negative. However, when I perform a simulation with just one nport, the dc values are correct. Has anyone seen this problem before? Is this some kind of bug in cadence spectre? Basically, I've imported a .cit file from HFSS with S-paramater data to be used in my nport. Please help!
There was a reported problem (see Sourcelink solution 11333942) which talks about problems with simulating multiple instances using citifile s-parameter files. This was fixed in MMSIM 126.96.36.1997 (ISR16 of MMSIM61). Are you using a version later than that?If not, try updating to the latest MMSIM61 or MMSIM62 ISR. If that doesn't work, please report it to customer support, with the data so that the problem can be reproduced and then fixed.Best Regards,Andrew.