A fully differential wideband analog front end for FMCW LiDAR application

To increase the system spatial resolution, this paper presents an eight-channel analog front-end (AFE) with wide bandwidth, low noise for frequency modulation continuous wave (FMCW) LiDAR application. The eight channels are independent of each other. For each channel, the fully differential shunt feedback transimpedance amplifier is adopted to improve the signal noise ratio, and the adaptive dc current cancellation (ADCC) is proposed to prevent the saturation with dc current. The cascaded differential amplifier is employed to achieve gain boosting, bandwidth compensation, and better driving capability. The proposed AFE is fabricated in 0.18 mu m CMOS technology. Experimental results indicate the largest transimpedance gain, bandwidth, input referred noise current and dc cancellation are 100 dB, 190 MHz, 37.7 nArms and 280 mu A, respectively. The power consumption of each channel is 70 mW with a 3.3 V power supply. The total area of the proposed AFE is approximately equal to 1.2 mm x 2.4 mm, including IO pads.

Automated summary

This paper presents an eight-channel analog front-end with wide bandwidth and low noise for FMCW LiDAR application. The proposed AFE utilizes techniques such as fully differential shunt feedback transimpedance amplifier, adaptive dc current cancellation, and cascaded differential amplifier to improve signal-to-noise ratio, gain, and bandwidth. Experimental results validate the performance of the AFE.