US 2019/0293757 A1 · METHOD FOR FMCW-BASED DISTANCE MEASUREMENT IN WAVEGUIDES

Abstract

The present disclosure relates to a method for FMCW-based measurement of a distance of an object located in a waveguide, as well as a corresponding distance measurement device that, in particular, may be used for fill-level measurement in surge pipes or bypass pipes of containers. The method is based upon the fact that the transmission signal that is typical in FMCW is not ramp-like, and thus is emitted with constant frequency modulation. Rather, according to the present disclosure, a curvature of the frequency ramp is set to be at least approximately proportional to the frequency dependency of the propagation velocity of the transmission signal in the waveguide. The distortion effect is thus compensated for in that the propagation velocity of the transmission signal in waveguides is not constant, but, rather, decreases with falling transmission frequency.

Claims11

Dependent claims

A method for FMCW-based measurement of a distance of an object located in a waveguide, the method comprising:

emitting a transmission signal along the waveguide in the direction of the object, wherein the transmission signal is emitted within a predetermined frequency band with a temporally-defined frequency modulation;
receiving the reflected signal after reflection at an object;
and
determining the distance using a difference frequency between the reflected signal and the transmission signal,
wherein a frequency dependency of the temporal frequency modulation of the transmission signal is set to be at least approximately proportional to the frequency dependency of the propagation velocity of the transmission signal in the waveguide.

2 more elements

A distance measurement device for FMCW-based measurement of a distance of an object located in a waveguide, the device comprising:

a high-frequency generation unit for generating an electrical high-frequency signal that, within the predetermined frequency band, exhibits the temporally-defined frequency modulation;
a signal splitter for splitting the electrical high-frequency signal;
at least one transmission/reception antenna for emitting the high-frequency signal as a transmission signal and/or for receiving the reception signal;
a mixer for mixing the electrical high-frequency signal with the obtained reception signal;
and
an evaluation unit configured to determine the distance using the difference frequency of the intermediate frequency signal, wherein the high-frequency generation unit is configured to set a frequency dependency of the temporal frequency modulation of the transmission signal to be at least approximately proportional to the frequency dependency of the propagation velocity of the transmission signal in the waveguide.

3 more elements

Dependencies are inferred from the claim text.

Method for fmcw-based distance measurement in waveguides

Life of this patent

Method for fmcw-based distance measurement in waveguides

Life of this patent

Abstract

Claims11