Method of operating radar sensor systems, corresponding circuit, system, and vehicle

Patent metadata

Field	Value
Publication number	US-11194035-B2
Application number	US-201916273737-A
Country	US
Kind code	B2
Filing date	Feb 12, 2019
Priority date	Feb 13, 2018
Publication date	Dec 7, 2021
Grant date	Dec 7, 2021

Abstract

A method of operating a radar sensor system includes: frequency down-converting a reception signal that is chirp-modulated with a sequence of chirp ramps to an intermediate frequency signal; and high-pass filtering the intermediate frequency signal to produce a high-pass filtered signal. High-pass filtering includes: first high-pass filtering, with a first corner frequency, the intermediate frequency signal at each chirp in the chirp modulation of the reception signal; and replacing the first high-pass filtering with a second high-pass filtering with a second corner frequency, the first corner frequency being higher than the second corner frequency.

First claim

What is claimed is:

1. A method of operating a radar sensor system, the method comprising:
frequency down-converting a reception signal that is chirp-modulated with a sequence of chirp ramps to an intermediate frequency signal; and
high-pass filtering the intermediate frequency signal to produce a high-pass filtered signal, wherein high-pass filtering comprises:
first high-pass filtering, at a first high-pass filter, with a first corner frequency, the intermediate frequency signal at each chirp in the chirp modulation of the reception signal; and
replacing the first high-pass filtering with a second high-pass filtering, at a second high-pass filter, with a second corner frequency, the first corner frequency being higher than the second corner frequency, wherein a first path of the intermediate frequency signal through the first high-pass filter is parallel to a second path of the intermediate frequency signal through the second high-pass filter.

2. The method of claim 1 , further comprising:
generating a transmission signal to produce the reception signal, the reception signal being a result of a reflection of the transmission signal at a detection target, wherein the transmission signal is chirp-modulated with a sequence of chirp ramps.

3. The method of claim 2 , further comprising controlling replacing the first high-pass filtering with the second high-pass filtering as a function of the sequence of chirp ramps chirp-modulating the transmission signal.

4. The method of claim 2 , further comprising discontinuously activating a transmission amplifier and amplifying the transmission signal using the transmission amplifier.

5. The method of claim 4 , further comprising activating the transmission amplifier during the sequence of chirp ramps.

6. A circuit, comprising:
an input node configured to receive a reception signal that is chirp-modulated with a sequence of chirp ramps and to frequency down-convert the reception signal to an intermediate frequency signal;
a high-pass filter circuit configured to receive the intermediate frequency signal and produce a high-pass filtered signal;
wherein:
the high-pass filter circuit comprises a first high-pass filtering arrangement with a first corner frequency and a second high-pass filtering arrangement with a second corner frequency, the first corner frequency being higher than the second corner frequency; and
the high-pass filter circuit is configured to provide, at each chirp in the chirp modulation, a high-pass filtering starting with the first high-pass filtering arrangement with the first corner frequency, wherein the first high-pass filtering arrangement is subsequently replaced by the second high-pass filtering arrangement with the second corner frequency.

7. The circuit of claim 6 , further comprising:
an output node coupled to an output of the high-pass filter circuit, wherein the high-pass filter circuit is intermediate the input node and the output node, wherein the high-pass filter circuit comprises a first high-pass filter having the first corner frequency and a second high-pass filter with the second corner frequency.

8. The circuit of claim 7 , further comprising:
a first switch activatable to direct the intermediate frequency signal from the input node towards either one of the first high-pass filter or the second high-pass filter; and
a second switch activatable to direct, towards the output node, the high-pass filtered signal from either one of the first high-pass filter or the second high-pass filter.

9. The circuit of claim 8 , wherein the first switch and the second switch are jointly activatable to provide a first filtering path and a second filtering path for the intermediate frequency signal from the input node to the output node via the first high-pass filter and the second high-pass filter, respectively.

10. The circuit of claim 6 , further comprising a chirp modulator configured to generate a transmission signal to produce the reception signal as a result of a reflection of the transmission signal at a detection target, wherein the chirp modulator is configured to produce the sequence of chirp ramps, wherein the high-pass filter circuit is coupled to the chirp modulator to provide, at each chirp in the chirp modulation, an alternated activation of the first high-pass filtering arrangement and the second high-pass filtering arrangement.

11. The circuit of claim 6 , further comprising an output node, with the high-pass filter circuit is intermediate the input node and the output node, and wherein the output node comprises an amplifier active on the high-pass filtered signal from the high-pass filter circuit.

12. The circuit of claim ii, wherein the amplifier comprises a variable gain amplifier.

13. The circuit of claim 6 , further comprising:
a chirp modulator configured to generate a transmission signal to produce the reception signal as a result of a reflection of the transmission signal at a detection target, wherein the chirp modulator is configured to produce the sequence of chirp ramps; and
a transmission amplifier configured to amplify the transmission signal, the transmission amplifier being activatable discontinuously.

14. The circuit of claim 13 , wherein the transmission amplifier is configured to be enabled during the sequence of chirp ramps.

15. A radar sensor system, comprising:
a circuit comprising:
an input node configured to receive a reception signal that is chirp-modulated with a sequence of chirp ramps and to frequency down-convert the reception signal to an intermediate frequency signal;
a high-pass filter circuit configured to receive the intermediate frequency signal and produce a high-pass filtered signal;
wherein:
the high-pass filter circuit comprises a first high-pass filtering arrangement with a first corner frequency and a second high-pass filtering arrangement with a second corner frequency, the first corner frequency being higher than the second corner frequency; and
the high-pass filter circuit is configured to provide, at each chirp in the chirp modulation, a high-pass filtering starting with the first high-pass filtering arrangement with the first corner frequency, wherein the first high-pass filtering arrangement is subsequently replaced by the second high-pass filtering arrangement with the second corner frequency;

a transmitter antenna configured to transmit a transmission signal to produce the reception signal as a result of a reflection of the transmission signal at a detection target; and
a receiver antenna configured to receive the reception signal, the receiver antenna being coupled to the input node of the circuit to transfer the reception signal to the circuit.

16. The radar sensor system of claim 15 , wherein the circuit further comprises:
an output node coupled to an output of the high-pass filter circuit, wherein the high-pass filter circuit is intermediate the input node and the output node, wherein the high-pass filter circuit comprises a first high-pass filter having the first corner frequency and a second high-pass filter with the second corner frequency.

17. The radar sensor system of claim 16 , wherein the circuit further comprises:
a first switch activatable to direct the intermediate frequency signal from the input node towards either one of the first high-pass filter or the second high-pass filter; and
a second switch activatable to direct, towards the output node, the high-pass filtered signal from either one of the first high-pass filter or the second high-pass filter.

18. The radar sensor system of clai

Assignees

• St Microelectronics Srl

Inventors

• Belfiore Francesco
• Scaccianoce Salvatore
• Michelin Salomon Amedeo
• Calcagno Antonino

Classifications

• G01S13/536

  using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves · CPC title

• G01S13/42

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S13/46) · CPC title

• G01S7/354 Primary

  Extracting wanted echo-signals (Doppler systems G01S13/50) · CPC title

• G01S13/343

  using sawtooth modulation · CPC title

• G01S13/931

  of land vehicles · CPC title