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

Abstract

A digital polar transmitter is presented that uses a digital-to-time-convert er (DTC) for wide-channel phase modulation with multiband support. DTC-based phase modula- tion enables high-efficiency polar operation with high-efficiency RFDAC. The transmitter uses coarse division inherent in DTC operation to generate TX output frequencies from 0.7 to 2.2 GHz with a limited DCO tuning range of only 7.3–8.7 GHz ( ±8.7%). Phase modulation of narrowband signals (e.g., one resource block) using DTC could result in spurs in output spectrum due to the almost periodic nature of DTC errors. A theoretical analysis is presented that predicts the location of these spurs and a technique to eliminate such spurs by appropriately adjusting the PLL frequency is introduced. A new digitally controlled-edge- interpolator architecture is also presented to minimize dynamic Manuscript received September 6, 2019; revised March 11, 2020; accepted March 13, 2020. Date of publication Apr il 30, 2020; date of current version June 29, 2020. This article was approved by Guest Editor Patrick Reynaert. (Corresponding author: Paolo Madoglio.) Paolo Madoglio and Ashoke Ravi are with Intel Corporation, Hillsboro, OR 97124 USA (e-mail: paolo.madoglio@intel.com). Yorgos Palaskas was with Intel Corporation, Hillsboro, OR 97124 USA. Jörn Angel is with Intel Deutschland GmbH, 47259 Duisburg, Germany. Jakob Tomasik was with Intel Deutschland GmbH, 85579 Neubiberg, Germany. He is now with Infineon T echnologies AG, 85579 N