A High-Linearity Energy-Efficient CMOS PA for Wireless Environment Monitoring

For power amplifier in wireless sensor network (WSN) nodes used for environment monitoring, there are three important factors, i.e. maximum output power, power efficiency and linearity. In this paper, two techniques are proposed to achieve good linearity, i.e. a negative feedback path with 180 degree phase shift, and a capacitance compensation technology to keep the overall input capacitance of driver stage constant. Furthermore, bond wire inductors with a high quality factor are proposed as chock inductors, which enhance both efficiency and linearity by raising drain voltage of common-gate transistors and cutting down the power loss in chock inductors. Simulation results demonstrate the PA achieves a maximum output power of 23.5 dBm with 42 % power added efficiency (PAE) and a 23 dBm output 1-dB compression point with 35% PAE. The two-tone test shows 5-10 dBc improvement in the third-order intermodulation distortion (IMD3) compared to a PA with on-chip chock inductors.