Ascertainment of calibration data to take temperature and voltage dependency of the HF radar signal phases in a radar system into consideration

Patent metadata

Field	Value
Publication number	US-12019180-B2
Application number	US-202117305728-A
Country	US
Kind code	B2
Filing date	Jul 14, 2021
Priority date	Jul 22, 2020
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

According to a first example implementation, the method comprises providing a local oscillator signal in a first radar chip based on a local oscillator signal generated in a further radar chip; supplying the local oscillator signal to a transmission channel of the first radar chip which, based on the local oscillator signal, generates an HF output signal; changing the temperature and/or supply voltage of the first radar chip; measuring phase values based on the local oscillator signal supplied to the transmission channel and of the corresponding HF output signal for different temperature values and/or for different supply voltage values of the first radar chip; and ascertaining calibration data based on the measured phase values for a phase calibration to compensate for changes in the phase of the HF output signal resulting from a change in the temperature and/or in the supply voltage.

First claim

The invention claimed is:

1. A method comprising:
providing a local oscillator signal in a first radar chip based on a local oscillator signal generated in a further radar chip;
supplying the local oscillator signal to a transmission channel of the first radar chip which, based on the local oscillator signal, generates an HF output signal;
changing one or more of a temperature or supply voltage of the first radar chip;
measuring phase values based on the local oscillator signal supplied to the transmission channel and based on a corresponding HF output signal for one or more of different temperature values or for different supply voltage values of the first radar chip; and
ascertaining calibration data based on the measured phase values for a phase calibration to compensate for changes in a phase of the HF output signal resulting from a change in one or more of a temperature or a supply voltage.

2. The method as claimed in claim 1 , wherein measuring the phase values comprises:
diverting a portion of a power of the HF output signal using a coupler, and
measuring the phase values based on the local oscillator signal supplied to the transmission channel and based on the diverted portion of the power of the HF output signal.

3. The method as claimed in claim 1 , further comprising:
receiving an HF radar signal that contains a radar echo from a radar target; and
mixing the HF radar signal down into a baseband and generating a baseband signal; and
detecting the radar target based on the baseband signal based on the calibration data.

4. The method as claimed in claim 3 , further comprising:
measuring, in operation, one or more of the temperature or the supply voltage,
wherein the radar target is detected based on the baseband signal of the calibration data and further based on the one or more of the temperature or the supply voltage.

5. The method as claimed in claim 3 ,
wherein the calibration data comprise a temperature coefficient that represents a temperature-dependent change in the phase of the HF output signal resulting from a temperature change, and
wherein the radar target is detected based on the temperature-dependent change in the phase of the HF output signal, the temperature coefficient, and of a measured temperature value.

6. The method as claimed in claim 1 , wherein ascertaining the calibration data based on the measured phase values comprises:
generating first information that represents a change in the measured phase values in relation to a change in one or more of the temperature of the first radar chip or the supply voltage of the first radar chip; and
modifying the first information based on second information to generate the calibration data.

7. The method as claimed in claim 6 ,
wherein the second information comprises a multiplication factor.

8. The method as claimed in claim 6 ,
wherein the second information is based on one or more of an instantaneous temperature or a supply voltage of the first radar chip measured in operation.

9. The method as claimed in claim 6 ,
wherein the second information is determined using a lookup table or a calculation algorithm.

10. The method as claimed in claim 6 ,
wherein the modification of the first information is based on a previously ascertained correlation between a change in the measured phase values and an actual change in the HF output signal.

11. The method as claimed in claim 6 ,
wherein the second information is the same for the first radar chip and further radar chips of a radar system.

12. The method as claimed in claim 1 , further comprising:
changing a frequency of the local oscillator signal, and
repeatedly ascertaining calibration data based on the measured phase values at the changed frequency of the local oscillator signal.

13. The method as claimed in claim 1 , further comprising:
providing a local oscillator signal in a second radar chip based on a local oscillator signal generated in a further radar chip;
supplying the local oscillator signal to a transmission channel of the second radar chip that generates an HF output signal based on the local oscillator signal;
changing one or more of the temperature of the second radar chip or the supply voltage of the second radar chip;
measuring phase values based on the local oscillator signal supplied to the transmission channel of the second radar chip and based on a corresponding HF output signal for one or more of different temperature values of the second radar chip or different supply voltage values of the second radar chip; and
ascertaining calibration data based on the measured phase values for a phase calibration for compensating for changes in the phase of the HF output signal resulting from a change in one or more of the temperature or a supply voltage.

14. The method as claimed in claim 13 , further comprising:
detecting a direction of arrival of a radar echo of a radar target based on a baseband signal and based on the calibration data for the first radar chip and the calibration data for the second radar chip.

15. A method comprising:
providing a local oscillator signal in a first radar chip based on a local oscillator signal generated in a further radar chip;
supplying the local oscillator signal to a reception mixer of a reception channel of the first radar chip that mixes an HF input signal down based on the local oscillator signal into a baseband, and generates a baseband signal, wherein an HF test signal that is based on the local oscillator signal is fed in as the HF input signal;
changing one or more of a temperature of the first radar chip or a supply voltage of the first radar chip;
measuring phase values based on the baseband signal for one or more of different temperature values of the first radar chip or different supply voltage values of the first radar chip; and
ascertaining calibration data based on the measured phase values for a phase calibration to compensate for changes in a phase of the local oscillator signal supplied to the reception channel resulting from one or more of a change in the temperature or a change in the supply voltage.

16. The method as claimed in claim 15 , wherein measuring the phase values comprises:
repeatedly changing a phase of the HF test signal and ascertaining a sequence of signal amplitudes of the baseband signal for a plurality of phases of the HF test signal at one or more of a first temperature or a first supply voltage and at one or more of a second temperature or a second supply voltage; and
calculating a first of the phase values for the one or more of the first temperature or the first supply voltage from the sequence of signal amplitudes ascertained at the one or more of the first temperature or at the first supply voltage, and calculating a second of the phase values for the one or more of the second temperature or the second supply voltage from the sequence of signal amplitudes ascertained at the one or more of the second temperature or the second supply voltage.

17. The method as claimed in claim 15 , further comprising:
receiving an HF radar signal that contains a radar echo from a radar target;
mixing the HF radar signal down into a baseband and generating a baseband signal in the reception channel; and
detecting the radar target based on the baseband signal and based on the calibration data.

18. The method as claimed in claim 17 ,
wherein detecting the radar target detecting a direction of arrival of a radar echo that can be assigned to the radar target.

19. The method as claimed in

Assignees

• Infineon Technologies Ag

Inventors

• Kulmer Josef
• Seler Ernst
• Li Hao
• Kraut Gunther
• Klymenko Oleksiy
• Hoelzl Patrick

Classifications

• G01S13/931

  of land vehicles · CPC title

• G01S7/032 Primary

  Constructional details for solid-state radar subsystems · CPC title

• G01S7/4008

  of transmitters · CPC title

• G01S13/44

  Monopulse radar, i.e. simultaneous lobing · CPC title

• G01S13/343

  using sawtooth modulation · CPC title