A Fully Integrated Bit-to-Bit 24/48Gb/s QPSK/16-QAM D-Band Transceiver with Mixed-Signal Baseband in 28nm CMOS Technology.

D-band (110-170GHz) transceivers (TRXs) have great potential to satisfy the fast-growing demand for ultra-high data rates, thanks to the abundant spectrum in D-band. The continuous scaling process enables D-band TRXs in low-cost CMOS technologies. Recently reported D-band TRXs have successfully achieved wireless data rates beyond 40Gb/s targeting various applications, including short-range wireless [1]–[2], medium-range links over low-cost dielectric waveguides [3]–[4], etc. However, designing a high data rate D-band TRX in CMOS technologies is still challenging. The $\mathrm{f}_{\text{MAX}}$ of CMOS transistors limits the sub-THz RF front-end (FE) performances. More importantly, at such high data rates, the digital baseband (BB) and ADC/DAC are power-hungry and complex to design, especially considering the 2x or 4x oversampling for pulse shaping. To alleviate the high-speed digital BB and ADC/DAC issue, a fully integrated bit-to-bit D-band TRX with mixed-signal BB in 28nm CMOS technology is presented in this paper, achieving a data rate of 24/48Gb/s for QPSK/16-QAM and supporting on-chip modulation/demodulation. Compared with prior works, the proposed TRX achieves the performance using on-chip modulation/demodulation, fully integrating all critical blocks from bits to RF and from RF to bits, including RF FE, mixed-signal BB, a frequency synthesizer, etc.