Power/signal integrity (PSI) SYZ solver: More accurate 3D FEM solver in SIwave

SIwave provides two power integrity PI (SYZ) solvers: the Standard SYZ solver and the PSI SYZ solver (PSI = Power/Signal Integrity). The main differences are:

1. Standard SYZ Solver – Uses a hybrid approach combining 2.5D Method of Moments (MoM), 2D FEM, and 3D MoM. It also relies on analytical models for traces, vias, split planes, and fringing fields. This greatly accelerates the simulation, especially for large PCB designs.

2. PSI SYZ Solver – Uses a full 3D FEM engine with prism elements. It is more accurate—particularly for complex geometries, high-frequency content, and micro-scale features (such as IC-level structures)—but also significantly slower.

Workflow for Using the PSI SYZ Solver

The workflow is identical to the standard solver. The user must define ports either manually or through the PI Wizard.

1. Load the PCB model using any supported format (EDB, IPC-2581, ODB++).

2. Launch the PI Wizard (orange icon) and select PI Wizard

3. Choose the power plane or RF line to analyze. In the Port column, add the ports.

• Use 0.1 Ω reference impedance for power planes.

• Use 50 Ω for RF lines.

4. If many power nets or signal nets are selected, save the setup. Click Configure, then Validate. SIwave will automatically place the ports. You can review them under Home > Circuit Element Parameters.

Ports may also be added manually using the port icon in the Home tab.

Solving and Comparing Results

1. Switch to the Simulation tab, choose Standard SYZ, and solve.

2. View the results using the Results panel. 

If the panel is not visible, enable it under View > Workspaces > Results.

Then select the PSI SYZ solver, apply the same setup, and solve again.

To compare both datasets:

• Right-click on a result plot and choose Plot Magnitude.

• Enable Preserve plots from other datasets.

• Change the dataset selector to the PSI SYZ results.

Result Summary

In this example:

• The Standard SYZ solver completed in 27 seconds.

• The PSI SYZ solver completed in 60 seconds, roughly twice as long.

These plots illustrate the performance/accuracy trade-off between the two solvers.