StatMod is a 3D EMC frequency domain simulation program that utilizes both a modified BEM and the PEEC numerical analysis methods. StatMod also has it's own built-in CAD tool for PCB design investigations. The program StatMod was especially developed for layout planning of low frequency analog circuits. Parasitic effects from arbitrary placed area fills and ground planes (ideal, non-ideal, no-ground, partial area ground simulations, with 2 full ground planes and an infinite number of partial area ground planes) can be taken into consideration. The calculation and visualization of current and charge density distributions are only a few of its special capabilities. StatMod, combined with RadiaSim, can calculate power supply RF radiation, the most influential component for PCBs. 3D PEEC simulation outputs of various PCB structures include I/V distribution, s-parameter, impedance, matrix, and SPICE partial - See bottom for example simulations of a complex Vcc structure extracted from a PCB.

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PCB Simulation		Cable Harness Simulation
StatMod Main PCBMod Static2D Static3D RadiaSim SLShow/SLGraph Resources News Training Support		Main CableMod Static2D RadiaSim SLShow/SLGraph Resources News Training Support

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The program StatMod makes the modelling of any three-dimensional layout structures of a PCB or IC design possible. It can be used to completely characterize the circuit concerning parasitic effects and is specially suitable for analog circuits and low frequency digital circuits.

StatMods diverse possible uses focus mainly on the fields of power supplies, automation technology, microsystem technology and medical technology.

StatMod was mainly developed for the beginning phase of layout generation to support the circuit designer in planning and structuring of the layout. Typical tasks are for example:

The modelling depending on frequency while maintaining a high degree of exactness is made possible by the program StatMod. Furthermore the skin effect is included into the analysis as well as arbitrary nonideal ground areas are considered on the layout.

The first characterization of a circuit is made easier by the speed optimized calculation methods of the field solvers included in StatMod. The user of the program has many possibilities of generating and loading the structures one wants to simulate with the aid of an efficient user interface.

StatMod has diverse kinds of output to represent the calculated values and generated simulation data:

StatMod is an efficient tool to support the developer in generating a circuit layout. It helps in solving complex tasks like:

StatMod can analyze PCB's with full or partial ground areas, encompassing ideal or non-ideal materials. All of these materials and their physical properties are variable, and analysis can consider inductance, resistance, capacitance, and conductance.

Scalar, as well as vector animation is possible, and StatMod can also handle gridded conductor areas.

Radiation calculations are handled by RadiaSim, when the user chooses a specific output from StatMod (IV analysis).

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Quick Overview of Simulation Capabilities of PCBMod, StatMod (PEEC), Static2D (BEM), and RadiaSim (MoM) for PCB EMC Simulations

The following example shows EMC analysis of a complex PCB structure using SimLab software.
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PCBMod:

Using PCBMod, one can select specific structures (nets) for detailed EMC analysis. Once these structures have been selected, the user creates a sub-project and PCBMod creates the proper file format for import into StatMod and Static2D, depending on the type of analysis required. The process is as follows:.

Selection: The user selects the layout structures that one plans to analyze within the PCB design environment. This simplifies the selection of arbitrary lines, area fills, pins, vias and ground planes by mouse-click.

Layout analysis: Collection of the selected structures, consideration of printed circuit board technology, reading in of user specific parameters.

 

Extraction: Analysis of layout geometries; inclusion of neighbouring unselected elements with adjustable detection threshold; building up of a logical connecting structure between the extracted elements; data processing of the extracted structures to create the proper file format. One can extract the entire net for a 3D PEEC simulation completed with StatMod, or one can extract a comprehensive 2D SPICE file for analysis with Static2D.

 

 

Static2D:

 

 

 

 

One can get both text and/or graphical outputs from Static2D of both the inductance and capacitance for the 2D cross section. Notice the color differentiation on the stripline structures above. With the analysis settings, one can set the background permittivity to fr4, or any other value. Shown above is the HSPICE W Model output from this extracted cross section (note: this cross section was not extracted from the PCB shown). Other outputs of Static2D include matrix (R, L, C, G), matrix (Z, V, T), SPICE Lumped, SPICE Distributed, Saber Lumped, Saber Distributed, ELDO Lossy Wire and the SLSim T model (SimLab specific model) - see the Static2D page for modes of propagation with differing velocities of complex 2D structures (there is an image on the Static2D page with two matrices, the potential mode shapes and current mode shapes, which represent the eigenvectors of the transmission line system - and mode impedances and mode admittances (real numbers without losses, complex numbers with losses)). For the TLM analysis, consideration of R, L, C, G will yield Poisson's equation (L=C=0), diffusion equation (R=C=0 or G=L=0), or the Helmholtz equation (lossless line)(R=G=0).

StatMod:

Note: the following examples were done to show the comprehensive outputs of SimLab tools. The example shown is of a complex geometry but the tools can, of course, handle problems with much simpler geometries.

After successful extraction of the components from PCBMod, the user then opens StatMod, sets up the sources and sinks (also connections to grounds). The user also sets up the simulation parameters (the PEEC settings). Note that we are attaching two sources to the structure, with no ground plane or ground structures and just one contact to an ideal ground point. We do not need to include the ground plane with the SimLab software, because the kernel was specifically designed to be accurate without it. Because we wish to complete an s-parameter simulation, two sources have been attached, both at 5V, much like a SPICE network simulation that engineers are accustomed to. Also shown is the PEEC meshing that is done prior to simulation, with the inductance and capacitance volume/surface mesh segments available for the user to view.

PEEC Numerical Analysis Settings: Notice that one can manipulate the numerical result analysis as follows: whether to include the R,L,C,G within the matrices for the PEEC calculation; whether the solution of the L and C matrices is accomplished by matrix inversion, shared or complete; the type of MoM (point fit, or Petrov-Gaelerkin); the search radius; whether to include off diagonal elements, or their relative percentages (note: these will be integral equations (EFIE) therfore full matrices); and the complete network matrix routines. For more details, download aEMCs_Into_SimLab_Software.zip, and see the Appendices, or see the Resources page for technical published documentation, or contact aEMCs directly. Also, unlike FEM (or BEM), far field conditions with MoM are accurately represented - the SimLab BEM tools are designed for small structures, with a close calculation, but StatMod's PEEC and RadiaSim's Mom are designed for all sizes and shaped structures - with small or large distance measurements. The numerical analysis parameters and the simulation setup settings are also available to the user, and these are helpful at discerning whether mesh step sizes, etc., are valid.

 

PEEC 3D Results:

 

a) Impedance: notice the inflection points above on the following graphs - these are resonance values at 150, 410 and 460 MHz.

b) S-parameter: Both the transmitted and reflected waveforms will be in the output. If one was to run a large frequency sweep for a broad spectrum of values and wished to review only selected values, SLShow (SimLab's 3D viewer) and SLGraph (SimLab's 2D viewer) allow the user to select one, many, or all values. The same user discretion is available with RadiaSim, and the user does not have to complete a field simulation with all of the values, only those values of concern resulting from the broad I/V StatMod simulation.

 

 

 

 

c) Current and Voltage Distribution (I/V Dist) - notice the color plots above and their corresponding legends showing the amount of current or voltage reaching certain areas of the net of concern at both the operating frequency and the resonance values. Other tools may claim that the "hotspots" occur where the color of the plot or trace is red. However, it is the user who must determine the acceptable level of EMI and it's effect on other components. Color plots and their differences only mean changes, not whether these traces and/or planes effect other components. Also, a trace will not be consistent throughout it's geometry in values. A tool that gives a constant color coding for the entire trace must indeed be very inaccurate - it must assume a constant value through layers. Notice the color differentiation for this complex structure alone. Differences may be small, and the design must be evaluated by the user in order to determine whether it will perform as desired - a tool that allows manipulation in order to achieve correct results is highly desirable for accuracy. EMC/EMI simulation is very much user intensive, and any result must be scrutinized by the user. On the far right is the voltage density at 460 MHz, with the color legend manipulated in order to discern specific values in specific regions, the red does not mean that voltage is high in those regions, rather it just means that those values are on the high end of the legend.

d) Matrix - useful in plotting inductance versus frequency - one can get a color plot of a range of values (2D graph - as shown), or you can get the standard matrix for a single frequency. A single matrix output will give a more accurate numerical value, but the results from both types of simulations are exactly the same. Also note the other selections available with SLGraph.

e) SPICE Partial - if one wished to have a SPICE partial circuit of a complex structure such as the net above, StatMod can perform the calculation. Shown, to the right, are the top and bottom of the text output file.

 

RadiaSim:

RadiaSim MoM Probes:
a) plane, cube, sphere, line, point, odd shape probe - All of these probes can be manipulated in size, position, rotation, and the mesh pattern of these probes can also be manipulated which allows the user control over the density of the measurements taken. By using the mesh pattern efficiently (a measurement is defined at each of the mesh's nodes, whereby the user can see a color value, or a vector local origin), a user can get as precise display of the PEEC/MoM as they wish. Alternatively, the user can have a coarse mesh for a more rapid analysis. Also, since the position of these probes can be manipulated, the line probe is placed at the same z position as the segment that needs to be measured. The cube probe is at the same height as the actual IC in question, and the point probe is in the approximate position of the single pin that needs to be analysed for the IC. If for some reason one needs an odd shaped probe, one has been included in this simulation, and a complete plane probe encompassing the entire net is right above the Vcc net. Viewing any of the results of the SimLab simulation tools is completely within the control of the user. A user can determine fully which results to display, depending on the type of simulation completed.

b) Results - Cube Probe and Plane Probe - note the isolated vectors for Hz and Ey

 

 

 

 

 

 

 

 

 

 

 

 

c) Results - Line Probe (traversing along the x axis) - note the isolation of a single point on the line probe (the line probe was divided into 400 points), and the isolation of Hz and Ey

d) Results - Point Probe (note: the last image is not from this simulation) - note the phase angles are a constant 45 degrees up to resonance

 

Notice the 2D point probe output of the dynamic E and H field simulations. Our material is copper, so notice the relatively constant line traversing left to right, with the mantissa plotted for E and H, and the abscissa for the phase angles. This implies a constant 45 degrees between the E and H field vectors, and a convergence to 0 degrees for resonance, whereby the phase angle differences between the E and H vectors is zero (pure resistance in response to an AC source). One can place the probes in any location, even within the dielectric and beside the trace of concern, giving victim susceptibility values. Due to the MoM, if the probes are placed in free space and arranged around the PCB, no meshing is required of the free space, thus quick simulation times can be achieved in comparison to FDTD or FETD simulations. Probes can be plane, point, cube, sphere, or irregular 2D shape.

Because StatMod utilizes the PEEC method, the analysis is accurate to the smallest of PCB structures with a high impressed frequency. This will allow the user to complete a frequency sweep encompassing all of the principle harmonic content accurately. Also, due to the PEEC method, the I/V distribution allows a very quick MoM simulation with RadiaSim. Since our fields simulation must include displacement currents (roughly above 10 kHz), we must have a dynamic E/H simulation. We can also take these measurements within the PCB itself, accounting for buried vias or embedded striplines and their emission effects on other neighboring structures (coming soon is the ability to simulate and predict common mode EMI due to differential mode switching as well as transient analysis for PCB structures with PCBMod/StatMod).