13.9 A 1.1V 28.6dBm fully integrated digital power amplifier for mobile and wireless applications in 28nm CMOS technology with 35% PAE

In today's connected world, smaller and leaner wireless applications emerge, calling for increasingly higher integration and smaller footprint, while ensuring high reliability and operation at limited supply voltages. In this context, the integration of the power amplifier (PA) is a challenge. Wireless transmission requires Watt-level peak power, which is usually achieved by means of a dedicated external PA, although monolithic integration of the PA within the radio transceiver has recently become more and more common [1-6]. In both cases, however, a dedicated PA supply voltage is usually provided, and the PA is typically operated at a higher supply voltage than that of the digital core of the transmitter to achieve the required output power level