Digital Power Amplifier for Modern Wireless Systems
Debopriyo Chowdhury, Reza Zamani and Ali Niknejad
The continued downscaling of CMOS technology has made digital circuits smaller and faster. Analog circuits, particularly passives, do not scale that well. In order to leverage the power of digital, this research focuses on the design of a digitally-assisted power amplifier in 65 nm CMOS technology. In theory, by introducing the signal envelope through digital means, the core PA devices can be operated in saturation, thus boosting the efficiency of the overall PA. This research will study the feasibility of using digital polar modulators for modern wireless systems like WLAN/OFDM and aim to find out the real pros and cons of using a digital PA vis-à-vis a traditional linear amplifier, taking into consideration metrics like out-of-band emissions, noise, efficiency, and output power.