Automotive Simulation using WIPL-D Pro CAD
This article demonstrates the application of WIPL-D
Pro to the simulation of electrically large automotivestructures. WIPL-D is ideal for such applications for
two reasons:•The geometry can be easily imported fromdifferent CAD formats, and edited using thepowerful user interface,•Due to higher order polynomial basis
functions, large structures are simulated very
quickly.

The model used here was made manually, instead ofbeing imported from some CAD file. We havesimulated placement of two antennas at two differentfrequencies:•Microstrip patch antenna at 2.5GHz (could beused as GPS antenna),•Monopoleantenna).

antennaat900MHz

Figure1. Model of the car.

(GSMBoth antennas are mounted on the roof of the car.
Because of symmetry of the model we have used one
symmetry plane. Real ground is modeled as PEC.
Results of our interest are radiation pattern and nearfield inside the car.
Figure 2. Patch antenna.

WIPL-D Modeling
The first step is modeling of the structure in WIPL-DPro. In the example that is shown in this paper, weused WIPL-D Pro 3D modeler (based on usingparameterized objects, quad plates and wires asbuilding blocks). As a result, obtained mesh is an
optimum one and minimizes memory usage andsimulation time.

Antenna mounting areas for two cases (monopoleantenna and patch antenna) are shown in Figs 3 and 4.

Model of the car is shown in Fig 1. One symmetry
plane and PEC plane are used, so only one half of thecar is modeled.
Model of the patch antenna that is added to the modelof the car is shown in Fig 2. As we can see, it is acircular patch coupling-fed by a microstrip line.

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Figure 3. Monopole antenna on car roof.

Figure 4. Microstrip patch antenna on car roof.

Figure 5. Radiation pattern of monopole antenna.

Simulation Results
Operation frequency is 900MHz for the model withmonopole antenna, and 2.5GHz for the model withpatch antenna. Direct incore solver is used for themodel with monopole, and for model with patch
antenna we have used the out-of-core solver.
Computer used for these simulations is Intel(R)Core(TM)2 Quad CPU, 2.67 GHz , 4 GB of RAM.
Number of unknowns, memory requirements, andsimulation time of analysis are given in Tab. 1.
Figure 6. Radiation pattern of patch antenna.

Table 1. Analysis characteristics

Model(Antenna)

No. ofunknowns

Memoryused [GB]Simulation
Time[min]Monopole

5556

0.242

1

Patch

42171

3.5 GB(42.3 GB
hard diskspace)

101

Radiation patterns of monopole and patch antenna on
car roof are shown in Figs 5 and 6. The second
parameter of interest is near field inside the car and in
the surrounding area. Near field is calculated in thesymmetry plane (Figs 7 and 8). Although near fields
are low inside the car in both cases, they are lower
when patch is used due to main-lobe orientation.

Figure 7. Near field for monopole antenna.

Conclusion
Based on presented, the simulation time is relatively
short, and we haven’t used adaptive order reduction inthese examples, which is a powerful technique that
could further speed-up simulation and eliminate theneed for the out-of-core solver. So, we can conclude
that WIPL-D software can be efficiently used for
simulation of electrically large automotive structures.
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Figure 8. Near field for patch antenna

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