A 20-33 GHz Direct-Conversion Transmitter in 45-nm SOI CMOS

This paper presents a 20–33 GHz direct-conversion transmitter implemented in 45-nm RFSOI CMOS technology. The transmitter features a divider-based quadrature clock generation circuit, two current-combined double-balanced mixers, and a balanced power amplifier (PA) employing stacked FETs. The transmitter chip achieves 19.1 to 22.4 dB of conversion gain with saturated output power of 16.7 to 20.4 dBm over 20 to 33 GHz at the differential output. Image rejection and carrier suppression are more than 29 dB and 36 dB after calibration. At a carrier frequency of 28 GHz, the transmitter chip achieves an error vector magnitude (EVM) of 5.1 % with 12 Gbps using 64-QAM.