The Wireless Workhorse: Mixed-Signal Power Amplifiers Leverage Digital and Analog Techniques to Enhance Large-Signal RF Operations

The ever-growing demand for higher data rates, power efficiency, and robust operations poses increasingly stringent performance requirements on wireless transceiver systems. This is particularly critical for mobile devices in both commercial and defense applications, where improving system size, weight, and power metrics and extending the battery lifetime are often the primary concerns. The power amplifier (PA) serves as the interface between the RF transmitter system and the antenna and is often considered one of the most critical building blocks in a wireless transceiver. This is because the PA's performance has critical impacts on multiple major transmitter metrics, including the output power level, power efficiency, bandwidth, and signal fidelity, and therefore governs the overall quality of service (QoS) of the wireless link [1], [2]. Moreover, due to their large-signal and high-power operations at RF frequencies, PAs often encounter unique design challenges and tradeoffs that deserve special attention [3].