RADIOING.com - eEngineer
EMI/EMC Analysis Software Characteristics
1. Simulation of
electromagnetic emissions and susceptibility for electrical and electronic
equipment including the internal circuits, printed circuit boards, and the
interconnecting cables/connectors, with considerations for the proposed
An interactive user interface for pre-route analysis of signal integrity/EMI
allowing for early investigation of board structures, stack-ups, materials,
technologies, and design rules.
Analysis of complex PCB’s with IC packages and any number of vias and signal
traces, including multiple, arbitrarily shaped power and ground planes.
Analysis of signal integrity effects including resonant frequencies of power and ground structures
with associated decoupling capacitors, crosstalk, power/ground bounce,
propagation delays, signal ringing, signal reflections, overshoot, undershoot,
simultaneous switching noise, impedance discontinuities due to changes in
signal layers or split supply planes, and noise coupling between signal lines
and supply planes.
5. Time domain effects such
as propagation delay, rise and fall times, reflections and ringing.
domain phenomena such as resonant modes and S-parameters
7. Emission reduction analysis
at the box and interconnecting levels such as for shielded coax, connectors and
enclosures; aperture radiation from equipment boxes and cabinets;
high-frequency effects in cable/connectors such as poor grounding or improper
connection; and package effects such as resonance, poor grounding, and radiated
8. 2-D analysis models for
structures with uniform cross-sections such as PCB stack-ups. 3-D analysis
models for non-uniform, non-planar structures such as connectors, vias, ground
planes, and power distribution grids.
9. Determination of any
frequency dependent parasitics for the resistance, inductance, capacitance, and
dielectric conductance associated with each PCB trace and via. Provide 3D parasitic extraction where 3D
structures are found such as traces, vias and arbitrarily shaped pads. This
should include the parasitic modeling and mutual couplings of all power/ground
planes, partial ground planes, split ground planes, arbitrarily shaped ground
planes, meshed ground planes, and power/ground trace structures.
10. Capability of accepting
customer inputs for the applicable test specifications.
to RF, digital, analog and mixed circuit designs.
12. Simultaneously simulate
radiated and conducted emissions.
13. Generate graphical
field plots and text reports.
14. PCB layout analysis for identification of nets with
crosstalk, ringing, time delays, overshoot, undershoot, settling time and noise
configurable reports of signal integrity parameters to enable the designer to
quickly and easily find and correct problems with a minimum of design
Electromagnetic emissions simulation immediately above or below a PCB allowing
for the identification of problem nets. This simulation should be done during
routing or at the post-layout stage. Simulate both individual or multiple nets
to enable first-pass EMC verification by locating highly radiating traces and
finding radiated field “hot spots. Predict emissions from a board; address the emissions
from pins and vias as well as from traces. Even if a board is encapsulated with
copper planes as striplines, emissions still occur from component pins and vias
protruding above the ground planes. To
analyze on the basis of signal integrity (i.e. pulse shape) and crosstalk, it
is necessary to perform a field analysis associated with the cross-sections of
all multi-conductor transmission line systems in order to obtain the
17. Field solver
utilization such as the boundary element method (BEM) field solver to produce
equivalent circuit models of general microstrip and stripline transmission line
structures. This provides outputs matrices of derived parasitics (e.g.
inductance, capacitance and resistance matrices), and voltage/current mode
shapes and velocities, impedances and a variety of transmission line models
that are readable by other suite elements or programs such as SPICE products
for the purpose of pre-layout simulation and rules generation.
18. A Ground
Plane Modeler capable of simulating two-sided boards and multi-layer boards
with partial power and ground planes.
It should be capable of automatically incorporating equivalent circuits
for no ground and imperfect ground designs into PCB transmission line networks
without the intervention of the user.
Solid ground planes offer the highest level of shielding against
crosstalk and emissions. However, for compactness and manufacturing economy, no
ground and partial ground planes are often employed. Slots and copper areas are
common, especially in double sided boards. If there are copper areas and power
nets, these should be analyzed to find where the copper areas are coupled to
19. A Database
Manager to allow for rapid display, addition and deletion of models in the component,
translation and subcircuit databases.
This would provide for tracing map user part codes to existing
components, attaching subcircuits to pins and using IBIS selected behavioral or
20. A suite
modeling method that can show results relative to changes. It should allow for the evaluation of the
effects upon radiated fields due to changes in single nets, groups of nets,
entire printed circuit boards, and complete systems combining boards, cabling
should include the vertical, horizontal and radial electric and magnetic
fields, either together or separately. Displays should include maximum field
vs. frequency, as well as the fields at the observation points in a three
dimensional graph resembling the measurement positions used in a testing
facility. The direct field contributions from the individual nets should be
displayed as well as the coupled field contributions from the induced currents
on the enclosure, cabling, ground planes and substrates. It should be capable
of displaying the current spectrum of each net on a board, as well as the
current waveforms of each component pin.
22. The user
interface should follow the functionality of a shielded testing facility or
open area test site. Users should be able to select and change the test
requirements and test setup. The software should provide internationally
recognized test standards such as FCC Part 15 and EIC CISPR and allow specific
test standards to be defined by the user.
23. IBIS compliant behavioral
modeling tool utilization to provide behavioral component models for use in
simulations, e.g. V-I curve-based signal integrity simulation models for use in
the emissions, signal integrity and crosstalk analysis. This allows behavioral models to be developed
conveniently from IC manufacturer data sheet information, or SPICE simulations
of more complex models. It should also be capable of accepting experimental
data. The models created are then placed within components that are easily
managed under the software’s database manager.
The software should automatically read in IBIS model files, create SPICE
driver and receiver models for the components (where applicable), and attach
the driver and receiver models to the appropriate pins on the specified part.
Note: I/O Buffer
Information Specification (IBIS), ANSI/EIA-656-1995 (IBIS) is an international
standard for the electrical specification of chip drivers and receivers. It
provides a standard file format for recording parameters like driver output
impedance, input loading, and rise/fall times for utilization by most any
software application such as IBIS simulation models. IBIS provides the V-I
curves for a driver’s HI and LO states, and its transition rate
characteristics. The use of V-I curves allows IBIS models for non-linear
effects like emitter-follower outputs, diodes, and TTL totem-pole drivers. IBIS is also effective in producing accurate
simulations of high-speed ringing and crosstalk and worst-case rise time