Energy efficiency in CMOS power amplifier designs for ultralow power mobile wireless communication systems

Abstract

Wireless communication standards keep evolving so that the requirement for high data rate operation can befulfilled. This leads to the efforts in designing high linearity and low power consumption radio frequency power amplifier(RFPA) to support high data rate signal transmission and preserving battery life. The percentage of the DC power ofthe transceiver utilized by the power amplifier (PA) depends on the efficiency of the PA, user data rate, propagationconditions, signal modulations, and communication protocols. For example, the PA of a WLAN transceiver consumes49% of the overall efficiency from the transmitter. Hence, operating the PA with minimum power consumption withouttrading-off the linearity is vital in order to achieve the goal of fully integrated system-on-chip (SoC) solution for 4Gand 5G transceivers. In this paper, the efficiency in CMOS PA is discussed through the review of multifarious efficiencyenhancement techniques in CMOS PA design. This is categorized into the review of efficiency in fundamental classes ofPA in which Class E achieves the highest efficiency of 67%, followed by complex architectures utilized to enhance theefficiency level of the PA in which the outphasing architecture achieved the highest efficiency of 60.7%.