This paper presents a 400MHz energy-efficient transceiver for body area applications. The transmitter employs a FIR-embedded phase modulator to shape signal and suppress unwanted side-lobe energy. It achieves 5.9% EVM value at 10Mb/s data rate. The receiver adopts zero-IF architecture and achieves a sensitivity of -86dBm at 10Mb/s HS-OQPSK modulaThis paper presents a 400MHz energy-efficient transceiver for body area applications. The transmitter employs a FIR-embedded phase modulator to shape signal and suppress unwanted side-lobe energy. It achieves 5.9% EVM value at 10Mb/s data rate. The receiver adopts zero-IF architecture and achieves a sensitivity of -86dBm at 10Mb/s HS-OQPSK modulation. Fabricated in 65nm CMOS process, the transmitter and the receiver consumes 2.98mW and 3.1mW from 1V supply, respectively. The TX and RX energy efficiency of the transceiver is 0.3 nJ/bit and 0.31nJ/bit, respectively.tion. Fabricated in 65nm CMOS process, the transmitter and the receiver consumes 2.98mW and 3.1mW from 1V supply, respectively. The TX and RX energy efficiency of the transceiver is 0.3 nJ/bit and 0.31nJ/bit, respectively.