A Cellular Multiband DTC-Based Digital Polar Transmitter With −153 dBc/Hz Noise in 14-nm FinFET

A digital polar transmitter is presented that uses a digital-to-time-converter (DTC) to enable high-efficiency polar RFDAC for multiband and wide-channel applications. The transmitter uses coarse division inherent in DTC operation to generate TX output frequencies from 0.7 to 2.2 GHz with DCO tuning range of only 7.3–8.7 GHz (±8.7%). The TX was fabricated in 14-nm FinFET and achieves noise of −153/−150 dBc/Hz for LTE5/LTE20 in Band1 with DTC power dissipation of 27 mW. The DTC was implemented using digital Automatic-Place-and-Route tools, requiring very limited analog layout resources.