ISO/TC 211 Multi-Lingual Glossary of Terms (MLGT)

Note 1 to entry: This is also equivalent to the ratio of the antenna radiation resistance (${\displaystyle R_{\text{rad}}}$ ) divided by the sum of the antenna radiation resistance and the antenna Ohmic resistance (${\displaystyle R_{\Omega }}$ ), as described in the following formula: ${\displaystyle {\eta }_{\text{l}}=\frac{P_{\text{rad}}}{P_{\text{in}}}=\frac{R_{\text{rad}}}{R_{\text{rad}}+R_{\Omega }}}$ where ${\displaystyle P_{\text{rad}}}$ is the total radiated power; ${\displaystyle P_{\text{in}}}$ is the total power accepted by the antenna; ${\displaystyle R_{\text{rad}}}$ is the antenna radiation resistance; ${\displaystyle R_{\Omega }}$ is the antenna Ohmic resistance.

Note 2 to entry: Antenna radiation efficiency (${\displaystyle {\eta }_{\text{l}}}$ ) is also called as Ohmic efficiency (${\displaystyle {\eta }_{\Omega }}$ ).