Radar system with balancing of the reception channels over a plurality of radar chips

Patent metadata

Field	Value
Publication number	US-12306336-B2
Application number	US-202217648858-A
Country	US
Kind code	B2
Filing date	Jan 25, 2022
Priority date	Jan 28, 2021
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

In some implementations, a radar device comprises: a clock input configured to receive a clock signal, a local oscillator configured to generate a first RF local oscillator signal based on the clock signal, and also an RF input configured to receive a second RF local oscillator signal. The radar device further comprises a phase shifter configured to shift the phase of the first RF local oscillator signal or of the second RF local oscillator signal by a settable phase value. A monitor circuit is configured to combine the first RF local oscillator signal and the second RF local oscillator signal and to generate a sequence of signal values based on the combined signal. A computing unit is configured to determine the relative phase of the second RF local oscillator signal in relation to the first RF local oscillator signal based on the sequence of signal values.

First claim

The invention claimed is:

1. A device comprising:
a clock input configured to receive a clock signal;
a local oscillator configured to generate a first RF local oscillator signal based on the clock signal;
an RF input configured to receive a second RF local oscillator signal, wherein the RF input is an input terminal configured to receive the second RF local oscillator signal from an external signal line coupled to the input terminal;
a phase shifter configured to shift a phase of the first RF local oscillator signal or a phase of the second RF local oscillator signal by a settable phase value,

a monitor circuit configured to generate a combined signal based on combining the first RF local oscillator signal and the second RF local oscillator signal and to generate a sequence of signal values based on the combined signal, wherein a specific phase value of a corresponding sequence of phase values is set for each signal value of the sequence of signal values; and
a computing unit configured to determine a relative phase of the second RF local oscillator signal in relation to the first RF local oscillator signal based on the sequence of signal values.

2. The device as claimed in claim 1 , further comprising one or more of:
a first frequency multiplier, which is connected between the local oscillator and the monitor circuit and is configured to multiply a frequency of the first RF local oscillator signal; or
a second frequency multiplier, which is connected between the RF input and the monitor circuit and is configured to multiply a frequency of the second RF local oscillator signal.

3. The device as claimed in claim 1 , wherein the monitor circuit further comprises:
an RF mixer configured to generate the combined signal by mixing the first RF local oscillator signal and the second RF local oscillator signal, wherein the combined signal is a baseband signal that is dependent on the settable phase value.

4. The device as claimed in claim 1 ,
wherein the combined signal has a DC component, and
wherein signal values of the sequence of signal values each represent an instance of the DC component of the combined signal.

5. The device as claimed in claim 1 , wherein the monitor circuit further comprises:
an analog-to-digital converter configured to generate, based on the combined signal, a digital signal corresponding to the sequence of signal values.

6. The device as claimed in claim 1 ,
wherein the sequence of phase values contains equidistant phase values that are distributed uniformly over one or more full phase rotations.

7. The device as claimed in claim 1 ,
wherein the computing unit is configured to calculate a spectral line of the sequence of signal values for the calculation of the relative phase.

8. The device as claimed in claim 7 ,
wherein the spectral line is a complex number and an argument of the complex number is calculated for the calculation of the relative phase.

9. The device as claimed in claim 1 , wherein the second RF local oscillator signal is an external RF local oscillator signal, and
wherein the input terminal is configured to receive the second RF local oscillator signal from an external local oscillator source via the external signal line, the external signal line and the external local oscillator source being external to the device.

10. The device as claimed in claim 1 , wherein the second RF local oscillator signal originates from an external local oscillator source that is different from the local oscillator and is arranged external to the device.

11. The device as claimed in claim 10 , wherein the device is a first radar chip and the external local oscillator source is a second radar chip.

12. A method for a radar system, comprising:
receiving a clock signal at a clock input of a radar chip;
generating a first RF local oscillator signal using a local oscillator integrated in the radar chip;
receiving a second RF local oscillator signal at an RF input of the radar chip, wherein the RF input is an input terminal configured to receive the second RF local oscillator signal from an external signal line coupled to the input terminal;
altering a phase of the first RF local oscillator signal or of the second RF local oscillator signal by a settable phase value using a phase shifter;
generating a combined signal by combining the first RF local oscillator signal with the second RF local oscillator signal, wherein a sequence of signal values is generated, and wherein a specific phase value of a corresponding sequence of phase values is set for each signal value of the sequence of signal values; and
determining, based on the sequence of signal values, a relative phase of the second RF local oscillator signal in relation to the first RF local oscillator signal.

13. The method as claimed in claim 12 ,
wherein generating the combined signal includes mixing the first RF local oscillator signal with the second RF local oscillator signal to generate a baseband signal, and
wherein the sequence of signal values represents DC components of the baseband signal for different phase values of the phase shifter.

14. The method as claimed in claim 12 ,
wherein before generating the combined signal, one or more of a frequency of the first RF local oscillator signal or a frequency of the second RF local oscillator signal is increased using a frequency multiplier.

15. The method as claimed in claim 12 ,
wherein the sequence of phase values contains equidistant phase values that are distributed uniformly over one or more full phase rotations.

16. The method as claimed in claim 15 , wherein determining the relative phase comprises:
calculating a spectral value from the sequence of signal values.

17. The method as claimed in claim 16 ,
wherein the spectral value is a complex number and an argument of the complex number is calculated for a calculation of the relative phase.

18. A non-transitory computer-readable medium storing a set of instructions, the set of instructions comprising:
one or more instructions that, when executed by one or more processors of a radar system, cause the radar system to:
receive a clock signal at a clock input of a radar chip;
generate a first RF local oscillator signal using a local oscillator integrated in the radar chip;
receive a second RF local oscillator signal at an RF input of the radar chip, wherein the RF input is an input terminal configured to receive the second RF local oscillator signal from an external signal line coupled to the input terminal;
alter a phase of the first RF local oscillator signal or of the second RF local oscillator signal by a settable phase value using a phase shifter;
generate a combined signal by combining the first RF local oscillator signal with the second RF local oscillator signal, wherein a sequence of signal values is generated, and wherein a specific phase value of a corresponding sequence of phase values is set for each signal value of the sequence of signal values; and
determine, based on the sequence of signal values, a relative phase of the second RF local oscillator signal in relation to the first RF local oscillator signal.

19. The non-transitory computer-readable medium of claim 18 , wherein the one or more instructions, that cause the radar system to generate the combined signal, cause the radar system to:
generate the combined signal based on mixing the first RF local oscillator signal with the second RF local oscillator signal, wherein the combined signal comprises a baseband signal, and wherein the sequenc

Assignees

• Infineon Technologies Ag

Inventors

• Lombardo Francesco
• Melzer Alexander

Classifications

• G01S7/4021

  of receivers · CPC title

• G01S7/4017

  of HF systems · CPC title

• G01S13/931 Primary

  of land vehicles · CPC title

• G01S7/411

  Identification of targets based on measurements of radar reflectivity (G01S7/415 takes precedence) · CPC title

• G01S7/41

  using analysis of echo signal for target characterisation; Target signature; Target cross-section · CPC title