An Efficient Mixed-Signal 2.4-GHz Polar Power Amplifier in 65-nm CMOS Technology

A 65-nm digitally modulated polar transmitter incorporates a fully integrated, efficient 2.4-GHz switching Inverse Class-D power amplifier. Low-power digital filtering on the amplitude path helps remove spectral images for coexistence. The transmitter integrates the complete LO distribution network and digital drivers. Operating from a 1-V supply, the PA has 21.8-dBm peak output power with 44% efficiency. Simple static predistortion helps the transmitter meet EVM and mask requirements of 802.11g 54-Mb/s WLAN data with 18% average efficiency.