An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The angle between the two directions in the main beam at which the power response has fallen to half its maximum value. → beam efficiency.

From → beam + → width.

Tâbe-pahnâ, from tâbé, → beam, + pahnâ "width," → broad.

The angle between extreme points of the main lobe of an antenna pattern where the sensitivity of the antenna is half the value at the center of the lobe. This is the nominal resolving power of the antenna system.

→ half; → power; → beam; → width.