Effective Isotropic Radiated Power

Effective isotropic radiated power (EIRP) is defined as an equivalent transmit power and is expressed mathematically as

where

EIRP = effective isotropic radiated power (W)

P_r = total power radiated from an antenna (W)

A_t = transmit antenna gain (W/W or a unitless ratio)

Expressed as a log.

EIRP (dBW) = P_r (dBW) + A, (dB)

In respect to the transmitter output

          

                  

Thus

            

P_t  = actual power output of the transmitter (dBW)

L_bo = back-off losses of HPA (dB)

L_bf = total branching and feeder loss (dB)

A_t = transmit antenna gain (dB)