A Reconfigurable Passive Switched-Capacitor TX RF Front End With −57 dB ACLR2

This letter presents a wireless transmitter (TX) front end in which the functionalities of digital-to-analog conversion, baseband filtering, and signal upconversion are implemented by a passive switched-capacitor (PSC) network. The result is a versatile architecture that fully benefits from CMOS scaling. The front end was integrated in a 65-nm CMOS technology and can support various channel bandwidths simply by adjusting the switching frequency for the PSC network. Thanks to its third-order reconfigurable filter, it maintains a thermal noise floor better than -156 dBc/Hz at a power dissipation of 45 mW. The measured prototype achieves an ACLR2 of -57 dB and an EVM of -31 dB for a 20-MHz 64-QAM OFDM and a 20-MHz 16-QAM signal, respectively.