Investigation of phase noise and jitter in CMOS sampling clock generation circuits for time-domain breast cancer detection system

摘要

Impulse radio ultrawideband (IR-UWB) technologies have been applied for time-domain breast cancer imaging systems. A Gaussian monocycle pulse (GMP) train with 200 ps pulse width is generated and the received GMP is converted from analog to digital by an equivalent time sampling circuit. A fluctuation of the sampling timing such as a jitter causes a degradation of reconstructed images. In this paper, the influence of jitter on confocal imaging is investigated. It is found that the SNR is improved by reducing the jitter. A low-jitter 102.4GS/s sampling clock generator in 65nm CMOS technology is proposed. This circuit achieved 1.98 ps jitter by 1.2V voltage supply and 0.90ps jitter by 1.45V voltage supply.