Equivalent Radiation Angle

Figure 1. Graphical representation of equivalent angle of radiation.

Ω e is the equivalent angle which is calculated from both sides of the half-values of the angles, ϑ M and φ M of the two planes.

(1) Ω e = φ M ϑ M

The radiated power density within the equivalent angle is assumed to be equal to the maximum radiated power density (in the main direction) and outside the equivalent angle, no power is emitted.

(2) D = 4 π Ω e