A 10.9GS/s, 64 Taps Distributed Waveform Generator with DAC-Assisted Current-Steering Pulse Generators in 0.18μm Digital CMOS

A distributed waveform generator (DWG) with DAC-assisted pulse generators is presented for the ultrafast waveform generation. It time-interleaves multiple pulse generators, and uses an on-chip transmission line for wideband pulse combining. Each unit pulse generator adopts a new current-steering topology which incorporates the edge combiner into the conventional current-steering structure for high-speed pulse generation. The transversal structure of the DWG enables a fully reconfigurable waveform generation. A 64-tap, 10.9 GS/S prototype was implemented in 0.18 mum standard digital CMOS technology. The average rise time of basis pulses generated from all 64 taps is 70 ps. The average tap delay is 91.8 ps. Characterization results and some example waveforms are shown in detail.