Analysis and design of concurrent class-F2 power amplifier based on power-series technique

Though the design procedures of dual-band power amplifiers (PAs) have been thoroughly studied in previous works, these studies have seldom delved into analyze the dual-band PA when it is driven by a concurrent dual-band signal. This paper presents the analysis and design of broadband class-F${}_2$ PA operating in concurrent mode. The class-F${}_2$ PA driven by a concurrent dual-band signal is analyzed using power series technique. It is illustrated that, compared to a concurrent class-B PA, the concurrent class-F${}_2$ PA exhibits an increased output power of 4.8 dB. Furthermore, when excited by a concurrent two-tone signal, the output power decrease of the class-F${}_2$ PA is merely 0.8 dB, as opposed to single-tone signal excitation. A broadband 1.8–2.2 GHz class-F${}_2$ PA supporting concurrent operation is designed and measured in this work. When excited by a single-tone signal, the broadband PA achieves a maximum output power of 41.1–42.4 dBm with a drain efficiency (DE) of 61.8%–67.3%. On the other hand, under the excitation of a concurrent two-tone signal centered at 2.0 GHz, the fabricated PA achieves an output power of 40.0–40.6 dBm with a DE of 60.0%–64.0% across a tone-spacing of 0–400 MHz.