A Broadband Digital Power Amplifier With 1-dB Psat Bandwidth of 5.5–9.5 GHz

Abstract

This letter presents a broadband digital power amplifier (DPA) with a transformer-based dual-resonant transmission line (TDRT) matching network in 65-nm complementary metal-oxide-semiconductor (CMOS). The broadband TDRT is proposed and analyzed first, and then the design flow is introduced to achieve a broadband and compact output-matching network. With the contribution of TDRT, the proposed broadband DPA delivers a saturated power of 21.2 dBm with drain efficiency of 37.6% at 7 GHz, and achieves a 1-dB bandwidth of 5.5–9.5 GHz with a fractional bandwidth of 53.3%, whose drain efficiency is 27.7%–37.6% in this frequency range.