A dual-band voltage-mode class-D PA for 0.8/1.8 GHz applications

This paper presents a compact dual-band voltage-mode class-D power amplifier module suitable for the LTE frequency bands at 0.8 GHz and 1.8 GHz. It uses a broadband GaN voltage-mode PA MMIC and a hybrid lumped element dual-band filter structure. The amplifier can handle various pulse-mode or digital modulation schemes. For a pulse-width modulated input signal the PA achieves a maximum output power of 5.4 W at 0.85 GHz and 4.3 W at 1.8 GHz. Peak drain efficiency is 84% and 54% for 0.85 GHz and 1.8 GHz, respectively. At 6 dB power back-off, drain efficiencies of 40% (0.85 GHz) and 25% (1.8 GHz) are obtained.