A Quadrature Switched Capacitor Power Amplifier

Wen Yuan, Vladimir Aparin, Jeremy Dunworth, Lee Seward, Jeffrey S. Walling
2016 IEEE Journal of Solid-State Circuits  
This paper presents an all-digital class-G quadrature switched-capacitor power amplifier (Q-SCPA) implemented in 65nm CMOS. It combines in-phase (I) and quadrature (Q) signals on a shared capacitor array. The I/Q signals are digitally weighted and combined in the charge domain. Quadrature summation results in a 3-dB signal loss; Hence the Q-SCPA utilizes a class-G dual-supply architecture to improve efficiency at backoff. Unlike polar/EER counterparts, the Q-SCPA requires no wideband phase
more » ... ator or delay matching circuitry. The Q-SCPA delivers a peak output power of 20.5 dBm with a peak PAE of 20%. It is measured with a 10-MHz, 64-QAM LTE signal and achieves an ACLR of <-30 dBc, with an EVM < 4%-rms.
doi:10.1109/jssc.2015.2496956 fatcat:6rdzfnqkvjh75jrl7cergej62i