A 390-GHz Outphasing Transmitter in 28-nm CMOS Alexander Standaert , Student Member , IEEE

Abstract

This article presents a 390-GHz outphasing trans- mitter in 28-nm CMOS. Generating higher order modulation schemes at terahertz (THz) frequencies is very challenging due to the essential nonlinear elements needed to generate signals above Fmax. Harmonic outphasing could provide an answer for transmitters which use a multiplier last topology. The topology addresses both amplitude and phase distortion issues, which are inherent for multiplier-last architectures. The 5-bit on-chip outphasing symbol generator is sufficient to generate modulation schemes from OOK to 16-STAR QAM. The chip is packaged with a direct chip-to-waveguide interface thus providing easy RF access through the WR2.2 waveguide interface. The transmitter can deliver a peak measured output power of −16 dBm with a 3-dB IF bandwidth of 16.5 GHz. The maximum achieved data rate was 6 Gb/s.