A second-order multi-bit ΔΣ TDC for high resolution IR-UWB radar systems

This paper describes a higher-order ΔΣ time-digital converter (TDC) design for high resolution UWB radar systems. To overcome “cross boundary” issue and in 1-bit first-order ΔΣ TDC, a 3-bit second-order ΔΣ TDC is proposed. For digital-intensive robust phase tracking, a dual delay lock loop (DLL) is adopted in which a digital phase rotator is designed to provide an unlimited phase capture range. The analysis and simulation results show that the proposed ΔΣ TDC enable high ranging resolution with optimal coefficient for IR-UWB radar system.