Techniques for processing amplitude modulation (AM) and frequency modulation (FM) in separate paths for simultaneous determination of range and velocity in an FMCW LIDAR system

A method for light detection and ranging (LIDAR), comprising:

• generating a first portion of a light signal to transmit towards a target;
• modulating the light signal with a transition from a higher power state to a lower power state at a section of a sweep signal to generate a pulsed light signal transmitted towards the target;
• receiving a return beam from the target based on the pulsed light signal, the return beam comprising an amplitude modulated (AM) signal portion and a frequency modulated (FM) signal portion;
• performing in-phase/quadrature (I/Q) detection to extract the AM signal portion and the FM signal portion of the return beam to produce an extracted AM signal portion and an extracted FM signal portion, respectively;
• and
• determining a range value and a velocity value of the target based on the extracted AM signal portion and the extracted FM signal portion.

A light detection and ranging (LIDAR) system, comprising:

• a light source to generate a frequency modulated light signal;
• an optical circuit comprising
• a modulator to modulate the light signal with a transition from a higher power state to a lower power state at a section of a sweep signal to generate a pulsed light signal transmitted towards a target;
• and
• a photodetector to receive a return beam from the target based on the pulsed light signal, the return beam comprising an amplitude modulated (AM) signal portion and a frequency modulated (FM) signal portion;
• a processing device coupled to the photodetector configured to:
• perform in-phase/quadrature (I/Q) detection to extract the AM signal portion and the FM signal portion of the return beam to produce an extracted AM signal portion and an extracted FM signal portion, respectively;
• and
• determine a range value and a velocity value of the target based on the extracted AM signal portion and the extracted FM signal portion;
• and
• optics to transmit the pulsed light signal and direct the return beam to the photodetector.