Design of a dual-band sequential power amplifier

In this article, we present a dual-band sequential power amplifier (SPA) to provide high efficiency at power back-offs and maximum output power at two separate working frequencies. The proposed SPA, including a carrier amplifier, a peaking amplifier, a power divider, and a combing coupler, is fabricated on Isola I-TeraMTRF boards with 3.45 dielectric constant, 0.0028 loss tangent, and 0.508 mm substrate thickness. The SPA provides 48 and 62% drain efficiency (DE) at 6 dB output back- off (OBO) and maximum output power at 1.1 GHz (first design frequency), and it also provides 52 and 65% DE at 6 dB OBO and maximum output power at 1.5 GHz (second design frequency). The designed SPA achieves above 39 dBm output powers at two working frequencies with about 10 dB gain and ±1.3 dB gain flatness. To the best of the authors' knowledge, it is the first time that a dual-band SPA is reported and demonstrated experimentally.