(Novermber 21) A Switched Capacitor Power Amplification Technique for Energy- and Area-Efficient Wireless Transmitters

In the era of internet of things (IoT) and wireless communication, energy- and area-efficient wireless transceivers are critical for extended battery life and small form factor of many systems. On the other hand, innovations in analog circuits have been driven by rapidly evolving semiconductor technology in line with Moore’s law. A switched capacitor power amplification (SCPA) technique, based on RF switched capacitor digital-to-analog converter architecture, offers very high energy efficiency and superior linearity for wireless transmitters. The measured peak Pout and power-added-efficiency (PAE) of a prototype SCPA are 25.2 dBm and 45%, respectively. For 802.11g 64-QAM OFDM modulated signal, the average Pout and PAE are 17.7 dBm and 27%, respectively, and the measured EVM is 2.6% without any predistortion applied. Class-G technique can be applied to SCPA to further enhance the efficiency. With additional supply voltage and advanced switching scheme for multiple supply voltages, the measured peak Pout and PAE are 24.3 dBm and 43.5%, respectively, whereas the average Pout and PAE are 16.8 dBm and 33%, respectively, for 802.11g signals.