A 9.4-11.4 GHz Low-IF Linear Transmitter Front-End with 47.2 dB Dynamic Range and 0.5 dB Gain Resolution in 40-nm CMOS

This paper presents a linearity enhanced wide dynamic range transmitter (TX) front-end with low intermediate frequency (IF) input in a 40-nm CMOS technology. The complementary nMOS and pMOS transimpedance amplifier (TIA) is utilized as the IF input stage for wideband impedance matching. A pseudo-differential up-conversion mixer is adopted to significantly suppress LO leakage. The wide dynamic range of gain control with high resolution is achieved by the digital controlled 7-bit attenuator with symmetric configuration. The fabricated TX front-end exhibits a minimum IP1dB of -3.36 dBm from 9.4 to 11.4 GHz and a 47.2 dB dynamic range with 0.5 dB tuning step. The measured root-mean-square (RMS) amplitude and phase error are below 0.89 dB and 4.9, respectively. Besides, it supports 400 MHz 64 QAM/500 MHz 256 QAM signal with EVM of -33.1/-32.3 dB at 10.7 GHz.