An ultra-low-power 32QAM RF transmitter

This paper introduces a quadrature modulation transmitter featuring the new IF-based quadrature backscattering technique to yield spectral efficient modulation schemes while reducing the power consumption. A 5.8 GHz RF-powered transceiver with the proposed transmitter was fabricated in 65 nm Si CMOS technology. The transmitter achieves 2.5 Mb/s, 32-QAM modulation while consuming 113 μW under 0.6 V power supply.