A 13-pJ/bit 900-MHz QPSK/16-QAM transmitter with band shaping for biomedical application

A 900-MHz QPSK/16-QAM transmitter targeted for biomedical application is proposed. Injection locking coupled with direct quadrature modulation at PA provides an efficient way to achieve band shaped QPSK/16-QAM modulation with effective side lobe suppression more than 38 dB. Fabricated in a 65-nm CMOS process, the TX can achieve maximum data rate of 50 Mbps/100 Mbps for QPSK/16-QAM with 6% EVM while occupying only 0.08 mm
²
. Under 0.77-V supply, the TX achieves 26 pJ/bit and 13 pJ/bit respectively with and without activating band shaping.