power added efficiency (RF amplifier) (PAE)
Power efficiency (PAE) is a characteristic value of RF power amplifiers andtransistors. It is particularly interesting for battery-powered mobile devices, since an increase in power efficiency can increase the battery-powered operating time.
Power efficiency is the ratio of power output to power input. Specifically, power efficiency (PAE) is the difference between the output and input power relative to the input power. The output power is the power that the amplifier delivers to the antenna or other load, the input power is the power that the amplifier receives from the upstream preamplifier, and the supplied power is the power that is drawn from the supply voltage.
For example, if the RF power output is 2.5 W, the input power supplied is 0.4 W, and the power required from the DC voltage source is 5 W, then this results in a PAE efficiency of 42%.
In the literature, efficiency is often given as the ratio of output power to input power.