Granted Patent B2

US 12,613,311 · App. 18/193,716 · Granted Apr 28, 2026

Inventors: Mayeul Jeannin (Munich, DE); Farhan Bin Khalid (Munich, DE); Dian Tresna Nugraha (Bandung, ID)

Assignee: Infineon Technologies AG

G01S7/4008G01S7/356G01S7/40G01S13/584

Abstract

Claims (67)

1 . A method of operating a radar system having a plurality of radar transmitters and at least one radar receiver, each radar transmitter having a transmitter adjuster for tuning an output of a respective transmitter, the method comprising:

in a calibration cycle,

transmitting from a single radar transmitter using the transmitter adjuster while all other radar transmitters in the plurality of radar transmitters are deactivated;

receiving a resulting signal on the at least one radar receiver;

identifying a target based on the resulting signal;

carrying out a range vector extraction on a decoded range Fourier transform corresponding to the target to obtain an extracted range vector;

obtaining an estimate of an error in the transmitter adjuster using the extracted range vector; and

tuning the transmitter adjuster according to the estimate of the error; and

in an operation cycle,

transmitting a signal using the plurality of radar transmitters, the signal being transmitted from each radar transmitter using the tuned transmitter adjuster; and

repeating calibration cycles interspersed between operation cycles during operation.

2 . The method according to claim 1 , wherein the tuning of the transmitter adjuster according to the estimate of the error uses an iterative approach to tune the transmitter adjuster over several iterations of the calibration cycle.

3 . The method according to claim 1 , wherein tuning the transmitter adjuster using the estimate of the error adjusts the transmitter adjuster using a fraction p of the error where p is no greater than 0.2 so that the respective transmitter is tuned successively over multiple calibration cycles.

4 . The method according to claim 1 , wherein in successive calibration cycles successive individual radar transmitters are used for transmitting.

5 . The method according to claim 1 , further comprising, in the calibration cycle, after transmitting from the single radar transmitter,

carrying out a range FFT over a fast time dimension on the resulting signal to obtain a range-slow time representation;

carrying out a Doppler FFT over a slow time dimension to obtain a range-Doppler representation;

carrying out a peak detection on the range-Doppler representation to create a target list; and

selecting the target from the target list.

6 . The method according to claim 5 , wherein receiving the resulting signal on the at least one radar receiver, carrying out the range FFT over the fast time dimension to obtain the range-slow time representation, and carrying out the Doppler FFT over the slow time dimension to obtain the range-Doppler representation are carried out in both the calibration cycle and the operation cycle,

the method further comprising processing the range-Doppler representation to identify positions of targets in both the operation cycle and the calibration cycle.

7 . The method according to claim 5 , wherein the method comprises:

identifying a main peak in the range-Doppler representation having a plurality of spurs offset from the main peak in a Doppler direction,

wherein obtaining the estimate of the error in the transmitter adjuster comprises carrying out an inverse discrete Fourier transform on complex numbers representing an angle and phase at the main peak and each of the spurs.

8 . The method according to claim 1 further comprising carrying out motion compensation on the extracted range vector to obtain a motion compensated extracted range vector, and using the motion compensated extracted range vector.

9 . The method according to claim 1 wherein the target is selected from a target list based on a criteria of being separated in range and Doppler from other targets in the target list and/or by representing a strong signal peak.

10 . The method according to claim 1 , wherein each transmitter transmits successively at a plurality of constellation points of a constellation, and each transmitter adjuster is a transmitter phase shifter arranged to control a phase of individual ramp phases of respective constellation points on the respective transmitter.

11 . A radar apparatus comprising:

a plurality of radar transmitters, each radar transmitter having a transmitter adjuster for tuning an output of the respective transmitter;

at least one radar receiver; and

a radar controller arranged configured to:

in a calibration cycle,

transmit from a single radar transmitter using the transmitter adjuster while all other radar transmitters of the plurality of radar transmitters are deactivated;

identify a main peak in a range-Doppler representation having a plurality of spurs offset from the main peak in a Doppler direction,

obtain an estimate of the error in the transmitter adjuster by carrying out an inverse discrete Fourier transform on complex numbers representing an angle and phase at the main peak and each of the spurs;

adjust the transmitter adjuster according to the estimate of the error; and

in an operation cycle,

cause the plurality of radar transmitters to transmit a signal, the signal being transmitted from each radar transmitter being tuned by the transmitter adjuster; and

repeat calibration cycles interspersed between operation cycles during operation.

12 . A radar apparatus, comprising:

a plurality of radar transmitters, each radar transmitter having a transmitter adjuster for tuning an output of a respective transmitter;

at least one radar receiver; and

a radar controller configured to

in a calibration cycle,

transmit from a single radar transmitter using the transmitter adjuster while all other radar transmitters in the plurality of radar transmitters are deactivated;

receive a resulting signal on the at least one radar receiver;

identify a target based on the resulting signal;

carry out a range vector extraction on a decoded range Fourier transform corresponding to the target to obtain an extracted range vector;

obtain an estimate of an error in the transmitter adjuster using the extracted range vector; and

tune the transmitter adjuster according to the estimate of the error; and

in an operation cycle,

transmit a signal using the plurality of radar transmitters, the signal being transmitted from each radar transmitter using the tuned transmitter adjuster; and

repeat calibration cycles interspersed between operation cycles during operation.

13 . The radar apparatus of claim 12 , wherein in successive calibration cycles successive individual radar transmitters are used for transmitting.

14 . The radar apparatus of claim 12 , wherein each transmitter transmits successively at a plurality of constellation points of a constellation, and each transmitter adjuster is a transmitter phase shifter arranged to control a phase of individual ramp phases of respective constellation points on the respective transmitter.

15 . The radar apparatus of claim 12 , wherein the radar controller is configured to, in the calibration cycle, after transmitting from the single radar transmitter,

carrying out a range FFT over a fast time dimension on the resulting signal to obtain a range-slow time representation;

carrying out a Doppler FFT over a slow time dimension to obtain a range-Doppler representation;

carrying out a peak detection on the range-Doppler representation to create a target list; and

selecting the target from the target list.

16 . The radar apparatus of claim 15 , wherein the radar controller is configured to carry out motion compensation on the extracted range vector to obtain a motion compensated extracted range vector, and using the motion compensated extracted range vector.

17 . The radar apparatus of claim 15 wherein the target is selected from a target list based on a criteria of being separated in range and Doppler from other targets in the target list or by representing a strong signal peak.

18 . The radar apparatus of claim 15 , wherein the radar controller is configured to receive the resulting signal on the at least one radar receiver, carry out the range FFT over the fast time dimension to obtain the range-slow time representation, and carry out the Doppler FFT over the slow time dimension to obtain the range-Doppler representation in both the calibration cycle and the operation cycle, and

process the range-Doppler representation to identify positions of targets in both the operation cycle and the calibration cycle.

19 . The radar apparatus of claim 15 , wherein the radar controller is configured to:

identify a main peak in the range-Doppler representation having a plurality of spurs offset from the main peak in a Doppler direction,

obtain the estimate of the error in the transmitter adjuster by carrying out an inverse discrete Fourier transform on complex numbers representing an angle and phase at the main peak and each of the spurs.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (57)