Third- and fifth-order baseband component injection for linearization of the power amplifier in a cellular phone

This paper proposes a new predistortion technique to improve the adjacent channel power ratio of the power amplifier (PA) in a cellular phone. This technique injects the third- and fifth-order distortion components in the baseband block, and eliminates the fundamental component from the injected signals in order to operate effectively up to near power saturation. We show this technique can raise the distortion-compensation limit, through mathematical analysis, and confirm it with simulation. We also examine the distortion compensation performance of the PA using a wide-band code-division multiple-access uplink signal and a high-speed downlink packet access signal, and the possibility of applying a new low-voltage high-capacity battery.