Far Field Parameters

To configure radiation pattern parameters, navigate to the Setup tab in the main window and select the Far-Field panel (Fig. 1).

The far field can be computed after calculating the current distribution. Thus, the parameters set in the Far-Field panel have no effect on the determination of the currents and can be modified at any time. However, the far field must be recalculated every time these parameters are modified.

There are four options for radiation pattern calculations:

Full 3D

The far field is calculated in angular ranges that cover the entire 3D space, allowing you to obtain 3D radiation lobes. The steps for the Theta (zenith) and Phi (azimuth) angles can be set in the Theta [deg] and Phi [deg] boxes.

Vertical

The far field is calculated at a vertical slice for a given Phi (azimuth) angle. The step for the Theta (zenith) angle can be set in the Theta [deg] box, while the fixed Phi can be set in the Phi [deg] box.

Horizontal

The far field is calculated at a horizontal slice for a given Theta (zenith) angle. The step for the Phi (azimuth) angle can be set in the Phi [deg] box, while the fixed Theta can be set in the Theta [deg] box.

Custom

The far field is calculated for the specified ranges of angles Theta (zenith) and Phi (azimuth). The start, step, and stop values for Theta and Phi can be set in the Theta [deg] and Phi [deg] boxes.

Additionally, the following parameters can be set:

Origin (X0,Y0,Z0)

This is any point used as a phase reference. Its coordinates do not affect the shape of the radiation pattern. The 3D radiation pattern will be plotted centered at this point.

Distance

This represents the distance from (X0,Y0,Z0) to an observation point in the far-field region. A normalized far-field pattern can be obtained by setting Distance = 1 meter.

The zenith and azimuth angles, Theta (θ) and Phi (ɸ), are shown in Fig. 2. The figure also illustrates the Distance R from the structure to an observation point in the far-field zone. These three numbers (R, θ, ɸ) define the spherical coordinates of the far-field point.

A frequently asked question is how to displace the center of the radiation pattern in a 3D plot displaying the radiation lobes. The answer lies in setting the Origin (X0, Y0, Z0) in the Far-Field panel. This allows you to adjust the reference point for the radiation pattern, enabling better visualization of the results. For more details, refer to this article:

• How to Adjust the Radiation Pattern Reference Point for Better Visualization