# 2x2D Antenna Patterns

The radiation patterns in the horizontal and in the vertical plane are available for nearly all commercial antennas. Full 3D patterns are not always available as they are more complicated to be measured.

The 2D antenna pattern is the graphical representation of the directional characteristic in a 2D plane. A polar diagram is used to describe the antenna pattern. While the vertical pattern results from $C\left(\vartheta ,\phi =const\right)$ , the horizontal pattern is formed from $C\left(\vartheta =const,\phi \right)$ .

To get smaller values, the pattern is often displayed on a logarithmic scale (dB). AMan offers both modes (linear or logarithmic).

The term radiation lobe is used for antennas whose radiation is concentrated in certain sectors. It is defined as the part of the directional characteristic which is limited by the angle with minimum field strength. If the considered lobe contains the main direction of transmission, it is called the main lobe, otherwise, secondary lobe. The lobe width, for example, ϑ3dB, indicates the angular expansion of the main lobe in a directivity pattern. The main direction of transmission is located in the main lobe.

The lobe width half value appears at the definition value of –3dB (dropping in the field strength of $\frac{1}{\sqrt{2}}$ and / or dropping of the radiation to half of the maximum value).

Figure 2 and Figure 3 show the coordinate systems used to display the patterns in the 2D view in AMan.