RF Measurement Library: Capturing Circuit Characterization Setups on the Schematic

Another design approach that Cadence supports that may not be obvious to all users…

The process of setting up a circuit simulation has historically been one of setting up all of the simulation control parameters (i.e. which analysis you want to run, what simulation data you want to save, accuracy tolerances, etc.) and then, after the simulation has completed, defining the measurements you want to make (i.e. noise figure, dc supply current, gain, etc.). The expectation here is that the user will set up the simulation appropriately to obtain accurate measurements. If that’s not done, the measurements may not be able to be made, or, even worse, the results of these measurements may not reflect circuit behavior in the way the designer expects.

What if instead, the designer could just define the measurement that they wanted to make and the tools could determine (with, perhaps, some user guidance) how to set up the simulation control parameters to ensure that the designer gets the data that they need?

This is the approach take with Cadence’s new measurement library, measureLib. Initially addressing RFIC measurements, measureLib is a library of design measurement cells that can be placed on a schematic view in Design Framework II.

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The measurements are defined by filling out the parameter list for the cells and connecting the various probe points to the design nodes.

This also has the added benefit of documenting the measurements directly on the testbench schematic.

To make the measurements, select the measurement analysis in the Analog Design Environment.

The simulation analysis controls and the waveform post-processing steps are then set up automatically and are available immediately after the simulation completes.

This alternate approach to the design characterization flow is still in the early stages but it is the hope that as it matures, it will allow designers to spend less time with tool setup and more time successfully designing circuits!

For more information about the measureLib, refer to the Virtuoso Spectre Circuit Simulator RF Analysis Library Reference in your MMSIM, version 7.1.1 and higher, documentation or contact your