High-performance front-end electronics for frequency-modulated continuous-wave interferometers

A high-performance analog electronic circuit for processing the signal from an absolute distance meter based on a frequency-modulated continuous-wave (FMCW) interferometer is presented. The front-end electronics includes a de rivative block followed by a the time-variant baseline restoration of the p hotodetector current. A high signal-to-noise ratio is ensured by avoiding t he use of a resistive transimpedance preamplifier and subsequent voltage pr ocessing, The paper details the electrical scheme of the preprocessing chai n as well as the experimental results from an actual prototype of a distanc e meter.