A D-Band Direct-Modulation 64-QAM Transmitter with On-Chip Digital Calibration in 16nm FinFET Technology

This paper presents a D-band direct-digital transmitter that employs RF-DACs to perform modulation in the RF domain. It achieves 64-QAM with a maximum data rate of $48 \mathrm{~Gb} / \mathrm{s}$ and an EVM of -23.8 dB. Meanwhile, a switch-based variable gain amplifier (VGA) and a digitally controlled artificial dielectric (DiCAD) are implemented on each of the I/Q paths to achieve refined on-chip amplitude and phase calibration. The transmitter is manufactured in 16 nm FinFET technology with an integrated frequency octupler and a power amplifier. The transmitter has a 3-dB bandwidth of $\mathbf{1 2 9 - 1 4 6 ~ G H z}$, a $\mathbf{P}_{\text {sat }}$ of 12.2 dBm, and a total DC power consumption of 235 mW.