32 GS/s ultra-high-speed UWB sampling circuit for portable imaging system

A 32 GS/s ultra-high-speed ultra-wideband (UWB) sampling circuit has been developed by use of a 65 nm CMOS technology. An equivalent time sampling technique was applied using an internal clock generator to achieve its low power consumption and high sampling rate. The generator consists of an eight-stage 2 GHz phase-locked loop, a 16-to-1 multiplexer and a frequency divider. Both a 20 mW low power consumption and a 32 GS/s high sampling rate were achieved. Gaussian monocycle pulse signals with a centre frequency of 450 MHz could be successfully converted to digital codes.