Once an FDTD simulation is finished, three far field items are added to the Far Field section of the Navigation Tree. These are the far-zone E-field component along φ direction, the far-zone E-field component along φ direction and the total far-zone E-field defined as:
:<math>|\mathbf{E_{ff,tot}}| = \sqrt{| E_{\theta}|^2 + |E_{\phi}|^2 }</math><!--[[Image:FDTD129.png]]-->
The 3D plots can be viewed in the project workspace by clicking on each item. The view of the 3D far field plot can be changed with the available view operations such as rotate, pan and zoom. A legend box appears in the upper right corner of the 3D radiation pattern plot, which can be dragged around with the left mouse button. The (maximum) '''Directivity''' of the radiating structure is displayed at the bottom of the legend box and is calculated using the definition:
:<math>D_0 = \frac{4\pi [S(\theta,\phi)]_{max}}{P_{rad}} = \frac{ 4\pi \left| \mathbf{E^{ff}}(\theta,\phi) \right|^2 |_{max} }{ \int\limits_0^{2\pi} \int\limits_0^{\pi} \left| \mathbf{E^{ff}}(\theta,\phi) \right|^2 \sin\theta \,d\theta \,d\phi }</math><!--[[Image:FDTD113.png]]-->
You can change the type of the 3D radiation pattern plot through the '''Radiation Pattern Dialog'''. In the '''3D Display Type''' section of this dialog you can choose from three options: '''3D Polar''', which is the default choice, '''Spherical Map''' and '''Cone'''. In the case of cone type, you can also set the size of the cones that are used for a vectorial visualization of the far field data. If the structure blocks the view of the radiation pattern, you can simply hide or freeze the entire physical structure or parts of it. Note that 3D radiation patterns are always positioned at the origin (0,0,0) of the spherical world coordinate system even though the radiation center of the structure may not be located at that point. Sometimes, it might be a good idea to hide the physical structure when you are viewing the 3D radiation patterns to avoid any confusion. In a 3D radiation pattern visualization, the fields are always normalized to the maximum of the total far field. For this reason, sometimes the cross-polarization component might get lost compared to the co-polarization component and you have to zoom in to make it visible.
You can also change the properties of the 3D radiation pattern plot by selecting the '''Properties...''' item in the right click menu of the plot's name in the Navigation Tree or by double-clicking the legend box. This opens up the '''Output Plot Settings Dialog'''. In general, there are two scale options: Linear (which is the default option) and dB. In the case of a linear plot, the plot range varies between 0 and 1. In the case of a dB plot, the range is fixed from -50 to 0dB. You can change the '''Color Map''' option as well the foreground and background colors of the legend box.
{| style="width: 600px" border="1" cellspacing="1" cellpadding="1"|[[Image:fdtd_out26_tn.png]]|[[Image:fdtd_out28_tn.png]]|}
Figure 1: The 3D total radiation pattern of a dipole antenna: (Left) polar type, and (Right) cone type.
===2D Radiation Graphs===