Optimum supply strategies for Power Amplifiers in cellular phones

The market for cellular phones is growing rapidly and cellular phones rank among the most prominent portable devices. All these phones are battery-powered and long use times on a single battery charge are required. The Power Amplifier (PA) draws most of the current from the battery in talk mode. Therefore, a reduction in this current will lead to a significant increase in talk time. This chapter covers powering the PA with the optimum supply voltage for each output power, which leads to a decrease in supply current. As described in chapter 1, this is one of the basic tasks of a Battery Management System.