A CMOS UWB radar sensor for high speed moving objects

A Fully Integrated 7–9 GHz UWB Radar IC with an LO Correlation Receiver

“…Recently, the demand for low-power and small radar sensors for monitoring and presence detection has drawn attention to the fully integrated radar IC solution. Although there are other potential radar candidates, such as Doppler and frequencymodulated continuous wave (FMCW) radars, the impulse radio ultra-wideband (IR UWB) radar has the advantages of a high resolution, a relatively simple design, and potentially low power realization [1][2][3][4][5][6][7].…”

“…Several papers have been published on the full UWB radar transceiver [1][2][3][4][5][6][7]. The direct sampling receiver of the millimeterlevel resolution is used for breathing rate motoring applications [2,5,6].…”

“…The self-mixing architecture of correlation receivers can be easily designed and is robust against small, undesired noise [4,7]. However, as the gain of the self-mixing receiver is proportional to the square of the mixer input magnitude, in the case of very small RF input, which is probably reflected from the far-distant target, the receiver has a much smaller gain, and the target becomes hardly detectable.…”

Digital-to-Time Converters for spur correction in Digital Frequency Synthesis

“…For example, fractional−N Phase-Locked Loops (PLLs) employ a DTC working at a few tens of MHz, placed in the reference or the divider path, to relax the Time-to-Digital Converter (TDC) requirements [32][33][34][35][36][37]. Radar applications employ DTCs at around 10 MHz to delay the sampling clock in the transmitter [38][39][40], or to span the timing-range of interest in the receiver [41]. In direct digital frequency synthesis, DTCs operating beyond 1 GHz have recently started to be employed for spur mitigation in Digital-to-Period Converters (DPCs) and Digital-to-Frequency Converters (DFCs) [28,42,43].…”