Generation of a digitally shaped 55-GBd 64-QAM single-carrier signal using novel high-speed DACs

We present a novel 2-channel arbitrary waveform generator (AWG) prototype, generating complex signal constellations with 6-bit digital-to-analog conversion (DAC) of up to 72 GS/s at a 6-dB bandwidth of 23 GHz. We generate a 55-GBd root-raised cosine shaped single-carrier 64-QAM signal.