A Comparison of Broadband and Tunable Delay-Line Structures in 45-nm CMOS

This paper presents a comparison of passive and active differential-mode delay-line structures. Active delay elements with and without bandwidth extension are considered for comparison. The key comparison metrics include delay-tunablity, signal integrity at the output of the delay-line, tapper-factor, bandwidth, group delay variations and the area consumption. Conforming to the presented comparison, a high tapper-factor, wideband and delay-tunable delay-line topology is selected and characterized in 45-nm CMOS process.