New Time-Saving Feature in IC6.1.4 ISR2: Plot S-Parameter Data Directly From ViVA!

20 May 2010 • 2 minute read

If you haven't heard about it....there is a new feature in IC6.1.4 ISR2 which makes troubleshooting circuits containing nports (s-parameters ) much easier and faster!

Starting in IC6.1.4 ISR2, you can now plot s-parameters directly in ViVA (without having to create a test bench and run a Spectre sp simulation).

This is a fantastic time-saver!

Why would I want to use this?

You may want to view the s-parameter data in the frequency domain prior to time domain simulation to verify that the s-parameter data is reasonable. The s-parameter data may be measured from lab equipment (Vector Network Analyzer), from simulation data, or from an EM field solver.
What often happens is when your time domain simulation (pss, harmonic balance, transient, etc. analysis) fails or the simulation results aren't reasonable, you want to look at the s-parameter data file contents to see if there's a problem... perhaps the data resolution is poor, the data is noisy, etc.

The old way:

Prior to IC 6.1.4 ISR2, in order to view the "native" s-parameter data, you had to

Create a schematic test bench containing an nport with the appropriate number of ports.
Run an sp analysis.
Plot the results in the Direct Plot form.

For 2-port s-parameter data, this was an inconvenience (15 minutes) .

For a large package model with (say) 25 to 200 ports, this was just downright PAINFUL. (an hour or more).

The new way:

Now in IC 6.1.4 ISR2, you can plot s-parameter data directly from the ViVA Results Browser in just a minute or two by:

File-Open Results
Load the s-parameter data file.
Plot the s-parameters

Yes, it is that simple!!!

Limitations:

The s-parameter must follow the naming convention filename.snp where n is the number of ports
Only Touchstone format is supported at this time. (Spectre and CITIfile formats to be supported in the future).
Linear 2 port noise parameters cannot be plotted (This should be fixed soon.)

For more information, please see Cadence Online Support solution 11640878.