A low-power small-size transmitter with discrete-time baseband filter for LTE in 65 nm CMOS

This paper presents the design of a low-power small-size transmitter with discrete-time baseband filter for LTE application operating at 1.8-2 GHz. The transmitter achieves 4.5 dBm output power with more than -46 dBc of LO feedthrough suppression and -38 dBc image rejection ratio. At -0.3 dBm transmitted power of LTE 5 MHz channel, ACLR is measured below -42 dBc for both upper and lower channels with 1.83 and 2.47 % EVM for QPSK and 16-QAM modulation signals, respectively. The prototype chip is fabricated in a 65 nm CMOS technology and dissipates 59 mA current from 1.2 V supply and 13 mA from 2.5 V supply.