CST STUDIO SUITE 2011: Integrating Simulation Technology

There is an increasing demand for evaluating
a component’s performance in the
system environment. The performance
of an antenna depends on the platform it is installed
on, for example, and the antenna itself
s Fig. 1 3D model of a cable harness in a compact car. Small window
shows cable cross section.
CST STUDIO
SUITE 2011:
InTEgraTIng
SImUlaTIOn
TEChnOlOgy
might be a system built from various RF components.
The importance of the EM system
simulation approach becomes obvious when
considering the electromagnetic compatibility
of a device. The overall performance depends
on the interaction of all the components, such
as PCBs, cables and housings (as illustrated by
the automotive scenario shown in Figure 1).
However, for each of the device’s components,
there might be specialized solutions that
will dramatically decrease simulation time. The
new CST STUDIO SUITE 2011 integrates
methods to synthesize and optimally handle
both the constituent components and their
interaction within a complex system. In addition,
the high performance computing (HPC)
options enable simulation with increasing complexity,
such as the example shown in Figure 2.
CST of America
Framingham, MA
Reprinted with permission of MICROWAVE JOURNAL ® from the December 2010 issue.
©2010 Horizon House Publications, Inc.

FREqUENCy DOMAIN sOLVER WIth CURVED
ELEMENts
With version 2011, the CST MICROWAVE
STUDIO (CST MWS) frequency domain solver will feature
curved tetrahedral mesh elements of high geometrical
orders. In comparison to using simpler curvilinear
elements (first order curved elements), which often suffer
from the creation of inaccuracies in the mesh representation,
higher order curved elements deliver a much
smoother representation of arbitrary surfaces.
As with all mesh adaptation schemes, simulations will
only converge to the correct results if mechanisms such
as True Geometry Adaptation are used. These actually
improve the representation of the input model continuously,
rather than simply refining the first discretization of
the model. The higher order curved elements will also be
available for the CST MWS eigenmode solver and the fast
resonant solver.
ELECtRICALLy LARgE stRUCtUREs
HPC can greatly benefit the simulation of very complex
structures, like the one shown in Figure 2, but switching
from standard volume methods such as FIT or FEM to
surface-based integral equation or ray tracing methods is
often the more efficient approach for electrically very large
structures. CST MWS features an integral equation solver
using the multilevel fast multipole method (MLFMM)
for structure sizes of up to about 1,000 wavelengths and
an asymptotic solver based on the shooting bouncing ray
method for even larger structures.
Both solvers can now use farfields as excitation sources.
These farfields can be computed by other CST MWS
solvers including the transient or frequency domain solvers.
This makes the calculation of an installed antenna’s
farfield possible, even for an electrically very large structure,
such as the ship shown in Figure 3. CST MWS
2011 also allows the importing of more than one farfield
source, thus enabling the computation of the coupling
between several antennas, or of the combined farfield of
multiple antennas.
For radar scattering simulations, the structure can be simultaneously
illuminated by multiple sources, the properties
of which can be set by means of an excitation list. This
enables the simulation of arbitrarily polarized incident
waves from different directions. The asymptotic solver
benefits from the inclusion of surface impedance models
for the simulation of coatings or seawater.
sENsItIVIty AND yIELD ANALysIs
CST MWS transient solver provides efficient computation
of broadband S-parameters and field results in one
single simulation run. In version 2011, sensitivity analysis
can evaluate the S-parameter dependencies on various
model parameters on the basis of this single broadband
simulation. Further evaluations for different model parameter
sets can be derived without restarting the full-wave
simulation. Hence, yield analysis for complex three dimensional
(3D) models is available at virtually no additional
computational cost.
OptIMIzAtION
The newly implemented trust region framework uses
Product Feature
s Fig. 2 Computation on a GPU cluster dramatically reduces simulation
time for this crosstalk analysis.
s Fig. 3 Bistatic RCS of a destroyer at 16.8 GHz.
parametric models to find optimal solutions for the given
goals, without rerunning expensive 3D simulations. By
employing the sensitivity information provided by both
of the general purpose electromagnetic solvers of CST
MWS—time and frequency domain—the number of 3D
simulations and, therefore, the optimization time can be
cut down dramatically.
MULtIphysICs
CST MPHYSICS STUDIO computes thermal and mechanical
effects. While not fully integrated in the design
environment, in version 2011 the temperature calculated
from the electromagnetic losses can be used to change
the material parameters for a consecutive electromagnetic
field simulation. CST MPHYSICS STUDIO now also features
a thermal solver on a tetrahedral grid.
EMC/EMI
CST STUDIO SUITE 2011 improves the integration of
CST CABLE STUDIO and the CST MWS TLM solver
(formerly CST MICROSTRIPES) into the CST design

environment. Users interested in the analysis of radiated
emissions and susceptibility will benefit from a single unified
environment for all EMC related modeling tasks, including
greatly simplified model set up and simulation.
In pre-processing, the definition of compact equivalent
aperture models and cable harnesses can be performed in
CST’s familiar design environment. Coupling between the
full 3D electromagnetic field and cable solvers enables direct
transient simulation of susceptibility problems in systems
containing complex cable bundles, including shielded
twisted pairs (see Figure 2).
sIgNAL AND pOWER INtEgRIty
For high accuracy and to address layouts with non-planar
elements such as wirebonds, a full 3D simulation is
often necessary. CST offers import filters to layout tools of
leading EDA vendors, such as Cadence®, Mentor Graphics®
or Zuken. All these links open the layout in the EM
design environment before setting up and running simulations.
Product Feature
In a major collaborative project, a link has been created
that allows Cadence layout engineers to stay within their
familiar environment while performing a full wave 3D extraction
and EM analysis in the background. Results are
back annotated to the Cadence environment, thus simplifying
the engineering workflow.
CST STUDIO SUITE version 2011 is addressing the
challenges of modern electromagnetic system design by
tightly integrating the latest in simulation technology within
an intuitive user interface. Streamlined workflows are
enabling real world problems to be tackled and solved in
a virtual environment, ultimately leading to an accelerated
and more cost-effective design cycle.
Cst of America,
Framingham, MA
(508) 665-4400,
e-mail: info@cst.com,
www.cst.com.
RS No. 300

For more information or to request a trial license,
please contact your local area representative.
CST AG – European Headquarters
Bad Nauheimer Str. 19
64289 Darmstadt
Germany
CST of America®, Inc. – US Headquarters
492 Old Connecticut Path, Suite 505
Framingham, MA 01701
United States
info@cst.com
http://www.cst.com