A novel 2.4 GHz CMOS class-E power amplifier with efficient power control for wireless communications

This paper presents the design of a novel RF power amplifier (PA) suitable for modern wireless communication systems. The PA employs switching mode class-E topology to exploit its soft-switching property to achieve high efficiency. The use of another class-E stage as a driver of power stage improves efficiency and increases the capability of circuit integration. A new output power control technique is utilized in order to control the output power of the proposed PA efficiently by using the array of switches and capacitors with different sizes. The proposed PA is simulated by Advanced Design System (ADS) in TSMC 0.18 μm CMOS process and simulation results show that the designed PA can deliver 21.09 dBm output power to 50 Ω standard load at 2.4 GHz with 57% Power-Added-Efficiency (PAE) from 1.8 V supply voltage and the output power can be controlled in 1 dBm steps with small drop in efficiency.