A Bits-to-Antenna F-Band 120-Gb/s CMOS RF-64QAM Transmitter for FutureG Wireless Links

This article presents a bits-to-antenna wireless transmitter (TX), fully integrated in 45-nm CMOS SOI, capable of surpassing 100-Gb/s data rates. The unique method of directly forming the 64QAM constellation within the RF domain, using three QPSK sub-TXs with controlled amplitude weighting, effectively mitigates the complications introduced by power amplifier (PA) nonlinearity in high-order modulations. This strategic approach opens avenues for significant enhancements in bandwidth and output power. This article further explores additional advantages of this TX design, such as local oscillator (LO) leakage suppression and improved output power, while going through the specifics of circuit block implementations. With a 40-GHz RF bandwidth, the RF-64QAM TX prototype achieves a measured data rate of 120 Gb/s with an effective isotropic radiated power (EIRP) of 16 dBm.