A multiband LTE SAW-less CMOS transmitter with source-follower-drived passive mixers, envelope-tracked RF-PGAs, and Marchand baluns

We present a multiband LTE SAW-less CMOS transmitter. Source followers, which drive passive mixers, contribute to the small-area and low-power transmitter. An envelope-tracking technique improves the linearity of RF programmable gain amplifiers, and Marchand baluns are suitable for multiband operation. The transmitter, which includes digital-to-analog converts and a phase-locked loop, covers 700 MHz to 2.6 GHz with -42 dBc ACLR. RX-band noise of -161 dBc/Hz is good enough for SAW-less operation.