Here's another great new feature that I've found very helpful...
Broadband SPICE is a new tool for S-parameter simulation in Spectre RF.
In the MMSIM13.1.1 (MMSIM13.1 USR1) release (now available on http://downloads.cadence.com), a new interpolation method, bbspice, has been introduced. The bbspice interpolation method generates the S-parameter macro models suitable for transient simulation. bbspice uses rational fitting with passivity and causality enforcement, and stores the generated models for later use.
You need to use IC6.1.6 ISR6 to access bbspice interpolation from the GUI.
In IC616 Subversions prior to ISR6, the option interp=bbspice is not directly supported in Virtuoso ADE. Use the Additional parameter list field in the Rarely used parameters group of the nport CDF form as a workaround.
Broadband SPICE models can be used with transient, SP, AC, harmonic balance, shooting PSS, and envelope-following analyses.
For more information on the nport, refer to the Using the nport Component section in the MMSIM 13.1.1 Virtuoso Spectre Circuit Simulator and Accelerated Parallel Simulator RF Analysis User Guide. Also see Article 20257868 on Cadence Online Support. http://support.cadence.com/wps/mypoc/cos?uri=deeplinkmin:ViewSolution;solutionNumber=20257868