## Stochastica Software

RobustPhysics’ entirely new and different EMC simulation software product Stochastica was formally launched at the IEEE EMC and SIPI Symposium in Grand Rapids MI, August 2023.

The Windows application is built on a 3D CAD geometry kernel (imports .stp and .iges files) and has a modern user interface which is custom-designed for user productivity, using Stochastica’s entirely new and different Statistical Wave Physics simulation technology. The most stunning feature is that all three analysis modules solve in only seconds; a full system-level, coupled field solution in typically less than one minute. The Statistical Wave Physics formulation does NOT scale with frequency, so it’s the same solution time for at 250 MHz and 10 GHz (and beyond). This unprecedented speed means fast updating of results plots as model parameters are changed, thus enabling the first truly interactive system-level EMC design process.

#### Aircraft System-Level EMC Model

1) Start by importing whatever simple 3D geometry data is available. Use Stochastica’s 3D modeling tool bar (including powerful Boolean construction tools) to represent the volume, surface area and shape of each E, H field domain (eg. cavity). Choose from a library of cavity field loss mechanisms to define the Q factor in each reverberant E, H field domain. Small details that can affect field levels at high frequencies are not neglected; they are the physical basis for Stochastica’s field uncertainty models and the reason that the simulation results are statistical.

2) Next, use Stochastica’s field modeling tool bar to define the area junctions between connected fields. Choose from a library of aperture and panel transmission section models to define how power flows between each. Then use the tool bar to define the field excitation sources – antennas, exterior field constraints, etc.SOLVE (Uncoupled) Cavity Fields and plot OUTPUT results – including Stochastic Limits (Max, Mean and Min) for any modelled field. Import a target RS level spectrum and use Net Power Inputs diagnostic plots to identify which specific Source(s) or Transmission path(s) need to be changed to correct exceedances.

4) Next, use Stochastica’s field modeling tool bar to define the area junctions between connected fields. Choose from a library of aperture and panel transmission section models to define how power flows between each. Then use the tool bar to define the field excitation sources – antennas, exterior field constraints, etc.SOLVE (Uncoupled) Cavity Fields and plot OUTPUT results – including Stochastic Limits (Max, Mean and Min) for any modelled field. Import a target RS level spectrum and use Net Power Inputs diagnostic plots to identify which specific Source(s) or Transmission path(s) are controlling exceedances.

3) Start by importing whatever simple 3D geometry data is available. Use Stochastica’s 3D modeling tool bar (including Boolean construction of solids) to represent the volume, surface area and shape of each E, H field domain (eg. cavity). Choose from a library of cavity field loss mechanisms to define the Q factor in each reverberant E, H field domain. Small details that can affect field levels at high frequencies are not neglected; they are the physical basis for Stochastica’s field uncertainty models and the reason that the simulation results are statistical.

#### Automobile System-Level EMC Model

2) Next, use Stochastica’s field modeling tool bar to define the area junctions between connected fields. Choose from a library of aperture and panel transmission section models to define how power flows between each. Then use the tool bar to define the field excitation sources – antennas, exterior field constraints, etc.SOLVE (Uncoupled) Cavity Fields and plot OUTPUT results – including Stochastic Limits (Max, Mean and Min) for any modelled field. Import a target RS level spectrum and use Net Power Inputs diagnostic plots to identify which specific Source(s) or Transmission path(s) need to be changed to correct exceedances.

4) Couple the two foregoing models with a single selection from the toolbar, to find all instances where cable segments pass through 3D cavity fields. Automatically create Penetration junctions and sub-divide the cable segments. Cable radiation resistance controls the cable-cavity field coupling. Stochastica calculates the ideal radiation resistance from each cable segment, but also incorporates lumped radiation impedance models for the residual radiation from cable ends and connectors (the controlling coupling after shielding is deployed). Solve the Coupled model to predict the max, mean & min Electric field levels and the max, mean & min voltage and currents at equipment terminals. NOW you’re ready for FAST, INTERACTIVE design of measures to meet EMC design targets.

1) Start by importing whatever simple 3D geometry data is available. Use Stochastica’s 3D modeling tool bar (including powerful Boolean construction tools) to represent the volume, surface area and shape of each E, H field domain (eg. cavity). Choose from a library of cavity field loss mechanisms to define the Q factor in each reverberant E, H field domain. Small details that can affect field levels at high frequencies are not neglected; they are the physical basis for Stochastica’s field uncertainty models and the reason that the simulation results are statistical.

3) Use Stochastica’s 3D modeling tool bar to create and locate multi-pin connectors. Then point & click to create wire and shield conductors between connector pins; thereby creating multi-conductor cable segments. Use the Cable Properties Solver to get the per-unit-length (PUL) coupling inductance and capacitance, resistance and conductance for each segment cross section.Create Junctions to accommodate Bends, Branches and Splices in the cable harness. At the cable ends, click to add terminal blocks which define load impedances and excitations. The excitation library includes voltage sources, current sources and antenna in a defined electric field source. Solve the cable harness to obtain terminal voltages, currents and crosstalk S parameters (NEXT, FEXT, etc.)

#### Who will use Stochastica ?

- Stochastica statistical wave physics modeling software is entirely new. It does not replace numerical simulation but is highly complimentary; it does not eliminate the need for EMC testing … so who will use it ?

- EM SIMULATION engineers will use it for 1000x faster predicts at 10+GHz; and when margins must be estimated
- EMC TEST engineers will find it simple to learn and quick to get results that aid test planning and results diagnosis
- PROGRAM-level EMC engineers will use it to integrate component supplier EMC data into a system-level EMC model

#### Contact us if you'd like to learn more ...

We are interested and avaialble to discuss how this new technology could be implemented to improve EMC engineering for your organization

11622 El Camino Real
San Diego, CA, 92130
PO Box 883.
Del Mar, CA 92014