Plotting 2D Far Field Patterns

The radiation pattern can be displayed as a 2D rectangular plot by selecting Results > Plot Far-Field Pattern > 2D Rectangular Plot in the main menu. This command will open the Radiation Pattern Cut dialog box (Fig. 1), where you can produce two types of plots:

• Conical plots are obtained with a fixed Theta and variable Phi.

• Vertical plots are obtained with a fixed Phi and variable Theta.

Choose a radiation pattern cut and click the OK button to execute the AN-XY Chart application, Fig. 2, where the radiation pattern is plotted vs. Phi if a conical plot was chosen (for fixed Theta) or vs. Theta if a vertical plot was chosen (for fixed Phi).

In the AN-XY Chart, go to the Plot menu to plot various parameters, including the total E-field, the linearly polarized field components E-theta (vertical) and E-phi (horizontal), the circularly polarized components E-right and E-left, the Axial Ratio, Power Density, Directivity, Gain, and, in the case of plane wave excitation, the Radar Cross Section (RCS).

The absolute value of the Axial Ratio takes on values between 0 and 1, as it is defined as the ratio of the minor axis to the major axis of the polarization ellipse. You can also plot the Axial Ratio in decibels. A circularly polarized field corresponds to an axial ratio of ±1 (or 0 dB), while a field is considered linearly polarized when the axial ratio is zero. A positive (negative) axial ratio corresponds to a right-handed (left-handed) polarized field.

The far-field pattern can also be represented in a 2D polar chart by selecting Results > Plot Far-Field Pattern > Polar Plot 1 Slice in the AN-SOF main menu (refer to Fig. 3). In this case, the chart will display information such as the maximum radiation, beamwidth, and front-to-rear/back ratios.

To plot two slices of a 3D far-field pattern in the same polar chart, go to Results > Plot Far-Field Pattern > Polar Plot 2 Slices in the AN-SOF main menu. A dialog box will appear, allowing you to select the two slices. You can choose from two vertical slices, two conical slices, or vertical-conical combinations (see Fig. 4).