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{{projectinfo|Application|Simulating The Performance Of Installed Antennas On Vehicular Platforms Using EM.Tempo|ART_GOLF_Fig_title.png|In this project, large parabolic reflectors fed by pyramidal horn antennas mounted on a complex, real-sized, automobile platform are modeled and analyzed using EM.Illumina and EM.Tempo.|*[[Building Geometrical Constructions in CubeCAD | CubeCAD]]

*[[EM.Illumina]]CAD Model*Pyramidal HornPatch Wizard*Parabola*Object of RevolutionYee Mesh

| 3.8×10⁶) S/m| Wheel rims

== Simulating the Patch Antenna on the Vehicle 's Roof ==

[[Image:Roof patch.png|thumb|left|480px420px| The location of the patch antenna on the vehicle 's roof.]]

By default, [[EM.Tempo]]'s mesh generator tries to place grid points at the corners of each graphic object's bounding box, and also at any internal boundaries any object may have. For models with a large number of complex geometric objects, this could drive the typical mesh cell size toward the "Absolute Minimum Grid Spacing", and would result in a much denser mesh than is required. Since the Golf model has more than 2000 distinct graphic objects, we will turn off some of these adaptive mesh options. A mesh density of 18 cells per effective wavelength is chosen for this structure with the absolute minimum grid spacing parameter set equal to 0.75mm. The figures below show the Yee mesh of the overall whole vehicle structure as well as the portion of the roof in the proximity of the installed patch antenna. The overall mesh involves <b><u>220 million</u></b> cells.

[[Image:Roof mesh.png|thumb|left|480px640px| The mesh of the vehicle structure generated by EM.Tempo.]]

[[Image:Roof patch mesh.png|thumb|left|480px420px| The A close-up of the mesh of the patch antenna and its neighboring region of the vehicle's roof.]]

The Mirage III CAD model has an approximate length of 15m, a wingspan of 8m, and an approximate height of 4<table><tr><td>[[Image:Roof pattern.5m. Expressed in freepng|thumb|left|640px| 3D far-space wavelengths at 850 MHzfield radiation pattern of the vehicle-antenna combination structure, with the approximate dimensions of patch antenna installed on the aircraft model are 42vehicle's roof.5 &#955;<sub>0]]</subtd> x 22.66 &#955;<sub>0</subtr> x 12.75 &#955;<sub>0</subtable>. Thus, for the purposes of [[EM.Tempo]], we need to solve a region of about 12,279 cubic wavelengths. For problems of this size, a very large CPU memory is needed, and a high-performance, multi-core CPU is desirable to reduce the simulation time.

[https://aws.amazon.com/ Amazon Web Services] allows one to acquire highThe figures below show the 2D polar radiation patterns of the roof-performance compute instances on demand, mounted patch antenna in the principal YZ and pay on a per-use basisZX planes. To be able to log into an Amazon instance via Remote Desktop Protocol (RDP), Comparing these graphs with those of the [[EM.Cube]] license must allow terminal services. For isolated patch antenna in the previous section reveals the purpose impact of this project, we used a c4.4xlarge instance running Windows Server 2012. This instance has 30 GB the mounting platform on the radiation characteristics of RAM memory, and 16 virtual CPU cores. The CPU for this instance is an Intel Xeon E5-2666 v3 (Haswell) processorthe installed antenna.

Mesh size<table><tr><td>[[Image: 220 million cellsHood mount.png|thumb|left|480px| The location of the patch antenna on the vehicle's hood.]]</td></tr></table>

Farfield Resolution: 2The figure below shows the details of the Yee mesh around the new location of the patch antenna.5 degreesDue to the curvature of the surface of most parts in this area, the generated mesh has denser grid lines. This increases the total number of mesh cells to more than <b><u>230 million</u></b>.

Simulation Time<table><tr><td>[[Image: 4 hours, 45 minutesHood mount mesh detail.png|thumb|left|480px| The details of the Yee mesh of the vehicle structure generated by EM.Tempo around the location of the patch antenna on the hood.]]</td></tr></table>

Power Threshold: The figure below shows the electric field distribution of the vehicle-40 dBantenna combination structure in the vertical ZX plane that passes through the center of the vehicle.

Thread Factor<table><tr><td>[[Image: 8Hood nearfield.png|thumb|left|640px| The dB-scale electric field distribution of the vehicle-antenna combination structure in the vertical ZX plane.]]</td></tr></table>

The thread factor setting essentially tells figure below shows the FDTD engine how many CPU threads to use during [[EM.Tempo]]'s time3D far-marching loop. For a given system, some experimentation may be needed to determine the best number of threads to use. In many cases, using half field radiation pattern of the available hardware concurrency works well. This comes from installed patch antenna on the fact that many modern processors often have two cores per memory portvehicle's hood. In other words, for many problemsFor this simulation, the FDTD solver cannot load and store data from CPU memory quickly enough far-field angular resolution was set to use all the available threads or hardware concurrency2. The extra threads remain idle waiting for the data, 5&deg; along both azimuth and a performance hit is incurred due to the increased thread context switching. [[EM.Cube]] will attempt use a version of the FDTD engine optimized for use with Intel's AVX instruction set, which provides a significant performance boost. If AVX is unavailable, a less optimal version of the engine will be used alternativelyelevation directions.

[[Image:Roof field.png|thumb|left|400px|]]<table><tr>[[Image:Roof mesh.png|thumb|left|400px|]]<td>[[Image:Roof mesh settingsHood pattern.png|thumb|left|400px640px|]] [[Image:Roof mesh settings advanced.png|thumb|left|400px|]] [[Image:Roof 3D far-field radiation pattern of the vehicle-antenna combination structure, with the patchantenna installed on the vehicle's hood.png|thumb|left|400px|]]</td>[[Image:Roof patch mesh.png|thumb|left|400px|]]</tr> [[Image:Roof pattern.png|thumb|left|400px|]] [[Image:Roof wheel mat.png|thumb|left|400px|]]</table>

[[Image:Roof wheel mat selectThe figures below show the 2D polar radiation patterns of the hood-mounted patch antenna in the principal YZ and ZX planes. Comparing these graphs with those of the two previous cases shows significant reflection and diffraction effects at the new location of the patch antenna.png|thumb|left|400px|]]

<table><tr><td>[[Image:Roof Hood yz cut.png|thumb|left|400px480px|]] [[Image:Roof zx cut2D linear-scale polar radiation pattern of the hood-mounted patch antenna in the YZ plane.png|thumb|left|400px|]] <br clear="all"/td> =Patch on Hood= Simulation Information: Mesh size: 230 million cells Farfield Resolution: 2.5 degrees Simulation Time: 5 hours, 25 minutes Typical Performance : 320 MCells</str><tr>Power Threshold: -40 dB Thread Factor: 8 <td>[[Image:Hood mountzx cut.png|thumb|left|400px480px|2D linear-scale polar radiation pattern of the hood-mounted patch antenna in the ZX plane.]]</td>[[Image:Hood mount mesh detail.png|thumb|left|400px|]]</tr></table>

[[Image:Hood yz cutTop_icon.png|thumb|left|400px30px]] '''[[#Introduction |Back to the Top of the Page]]'''

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