US 12,169,242 B2
FMCW LiDAR distance measurement apparatus
Frank Blöhbaum, Denzlingen (DE); and Christoph Menzel, Denzlingen (DE)
Assigned to SICK AG, Waldkirch (DE)
Filed by SICK AG, Waldkirch (DE)
Filed on Apr. 25, 2022, as Appl. No. 17/728,585.
Claims priority of application No. 21170473 (EP), filed on Apr. 26, 2021.
Prior Publication US 2022/0342071 A1, Oct. 27, 2022
Int. Cl. G01S 17/34 (2020.01); B66C 13/46 (2006.01); G01S 7/4912 (2020.01)
CPC G01S 17/34 (2020.01) [B66C 13/46 (2013.01); G01S 7/4917 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An FMCW LiDAR distance measurement apparatus comprising:
a light source that generates a frequency modulated transmission light beam as a transmission signal having a predetermined frequency deviation and transmits said frequency modulated transmission light beam into a measurement zone;
a light receiver that is configured to receive light reflected by objects in the measurement zone as a reception signal; and
a mixer that is configured to mix at least a portion of the transmission signal with the reception signal and with an oscillator frequency to generate a mixed signal,
wherein the distance measurement apparatus is configured to adapt the oscillator frequency to a desired measurement zone,
and wherein the mixer comprises an avalanche photodiode (APD), configured to perform the mixing of at least a portion of the transmission signal, and the reception signal and a bias voltage of the APD acted on by the oscillator frequency.