A 50-MHz Logarithmic Amplifier for Use in Lidar Measurements

Abstract

A high-speed logarithmic amplifier that has been successfully used to improve the dynamic range of a scanning lidar is described. The amplifier incorporates built-in baseline correction and calibration circuits, allowing for real-time offset and temperature corrections. Using a commercial 12-bit analog-to-digital converter, the equivalent linear input signal can be recovered to an accuracy of ±0.5%, while maintaining a dynamic range of more than four decades.