研究目的

Investigating the development of a pulsed-coherent time-of-flight (ToF) receiver for a laser ranging system to achieve high resolution and fast acquisition.

研究成果

This prototype presents a detection architecture using pulsed-coherent coarse-fine ToF measurement that combines the benefits of pulsed detection and coherent detection in a segmented converter design. Post-edge envelope detection reduces the sensitivity to walk error so that the pulsed detection is sufficiently accurate as the coarse measurement for the fine coherent detection. The fast settling AGC loop enhances the sampling rate, and the phase-invariant variable-gain analog front end improves the precision. This ToF receiver can theoretically achieve 40-μm resolution with 1-MHz sampling rate.

研究不足

The walk error of the envelope pulse detection can easily be larger than a 19-GHz period, thus limiting the resolution. Linearity is crucial in a coherent receiver to maintain fine phase information.