Linear power amplification with high back-off efficiency

Abstract Transmitters for high rate data communications (e.g., WiFi and LTE) need to simultaneously meet a number of conflicting requirements: high Pout, efficiency, and peak-to-average power ratio and low out-of-band emissions. Outphasing is a potentially useful technique for realizing such power amplifiers (PAs) in low-cost, digital CMOS for integration with the digital baseband. In this chapter, outphasing techniques with digital-assistant approaches are discussed, analyzed, and demonstrated to improve back-off efficiency in CMOS PA design.