The array factor power gain is 8. The boresight direction is at zero azimuth and elevation angles and is the direction of strongest radiation in the polar pattern, The main beam consists of the radiation between boresight direction and the first null. The azimuth angle is measured between the boresight direction and the radiation direction in the horizontal plane. The elevation angle is measured between the boresight direction and the radiation direction in the vertical plane. The sidelobes consist of continuous regions of radiation between nulls, discounting the main beam.
Nulls are directions in which there is no radiation.
Nulls consist of lines or points on a far-field sphere. The E-plane radiation pattern is a plot of the power radiated as a function of angle away from boresight, in the plane defined by the boresight direction and the electric field vector. It is defined for linear polarisation cases only. Vertical polarisation occurs when the electric field vector has components in the vertical direction and, if the radiation is at a non-zero elevation angle, also along the projection of the radiation direction onto the azimuth plane. The electric field vector is always at right angles to the direction of propagation.