</table>
==Changing the Source Polarization==
In the last part of this tutorial lesson, you will change the polarization of your short dipole transmitter and see the effect of the polarization change on the coverage map. Open the property dialog of the source and change its "Direction Unit Vector" to uX = 1, uY = -1, and uZ = 0. This will align the short dipole radiator parallel to the direction of most nearby streets. Keep the same 10A dipole current. If you close the source dialog and open it again, you will notice that the direction vector has been normalized as uX = 0.707, uY = -0.707, and uZ = 0. Run an SBR analysis of the scene and visualize the received power coverage map.
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[[Image:PROP261.png|thumb|550px|The received power coverage map of the Manhattan scene with the horizontally polarized dipole source.]]
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From the above figure, you can see that the maximum received power level has increased by about 6dB. You can also see more signal paths compared to the vertical polarization case. Visualize the three electric field component distribution maps and compare them with the data of the previous case. Note that in this case, the Z-component of the electric field is entirely due to multipath effects.
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[[Image:PROP262.png|thumb|380px|The distribution of the X-component of electric field due to the horizontally polarized dipole source.]]
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[[Image:PROP263.png|thumb|380px|The distribution of the Y-component of electric field due to the horizontally polarized dipole source.]]
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[[Image:PROP264.png|thumb|380px|The distribution of the Z-component of electric field due to the horizontally polarized dipole source.]]
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Next, rotate your transmitter by 90° counterclockwise. This is equivalent to changing the "Direction Unit Vector" of the short dipole source to uX = 0.707, uY = 0.707, and uZ = 0. in this new orientation, your source is aligned perpendicular to the direction of most nearby streets. Keep the same 10A dipole current. Run an SBR analysis of the scene and visualize the received power coverage map. You will find that although the rotation of the dipole source does not change the maximum received power level, more penetrating signal paths appear on the nearby streets and they extend to longer distances.
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[[Image:PROP267.png|thumb|550px|The received power coverage map of the Manhattan scene with the horizontally polarized dipole source rotated 90° counterclockwise.]]
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Also visualize the three electric field component distribution maps. The Ex and Ey field maps are consistent with the radiation pattern of the short dipole radiator, which has a donut shape with its maximum normal to the dipole axis.
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[[Image:PROP268.png|thumb|380px|The distribution of the X-component of electric field due to the horizontally polarized dipole source rotated 90° counterclockwise.]]
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[[Image:PROP269.png|thumb|380px|The distribution of the Y-component of electric field due to the horizontally polarized dipole source rotated 90° counterclockwise.]]
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[[Image:PROP270.png|thumb|380px|The distribution of the Z-component of electric field due to the horizontally polarized dipole source rotated 90° counterclockwise.]]
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</table>
== References ==