Radar device and method for detecting hardware faults of a radar device
The present disclosure relates to a radar device, including a transmitter circuit configured to generate an RF oscillator signal and to transmit an RF fault detection signal based on the RF oscillator signal, a receiver circuit configured to receive an RF reception signal based on the RF fault detection signal and to mix the RF reception signal with the RF oscillator signal in order to obtain a down-converted reception signal, and a fault detection circuit configured to detect a hardware fault of the radar device based on a phase of the down-converted reception signal.
1. A radar device, comprising:
a transmitter circuit configured to generate an RF oscillator signal and to transmit, during a first fault detection timeslot, a first RF fault detection signal derived from the RF oscillator signal and transmit, during a second fault detection timeslot, a second RF fault detection signal derived from the RF oscillator signal, wherein the first RF fault detection signal and the second RF fault detection signal have a predetermined frequency offset with respect to the RF oscillator signal;
a receiver circuit configured to:
receive the first RF fault detection signal as a first RF reception signal via antenna crosstalk coupling with the transmitter circuit, and mix the first RF reception signal with the RF oscillator signal in order to obtain a first down-converted reception signal, and
receive the second RF fault detection signal as a second RF reception signal via antenna crosstalk coupling with the transmitter circuit, and mix the second RF reception signal with the RF oscillator signal in order to obtain a second down-converted reception signal; and
a fault detection circuit configured to determine a first phase of the first down-converted reception signal, determine a second phase of the second down-converted reception signal, and detect a hardware fault of the radar device based on a difference between the first phase of the first down-converted reception signal and the second phase of the second down-converted reception signal,
wherein the hardware fault includes at least one RF signal conduction breakage defect in a transmitter signal path of the transmitter circuit or in a receiver signal path of the receiver circuit.
2. The radar device as claimed in claim 1 , wherein the fault detection circuit is configured to determine the first phase of the first down-converted reception signal based on a discrete Fourier transformation of the first down-converted reception signal.
3. The radar device as claimed in claim 1 , wherein the fault detection circuit is configured to determine a discrete spectral component of the first down-converted reception signal that corresponds to the first RF fault detection signal based on a Goertzel algorithm and to detect the hardware fault based on a phase of the discrete spectral component.
4. The radar device as claimed in claim 1 , wherein the transmitter circuit is configured to generate the RF oscillator signal as a frequency-modulated continuous wave radar signal.
5. The radar device as claimed in claim 1 , wherein the transmitter circuit is configured to transmit the first RF fault detection signal and the second RF fault detection signal during predetermined fault detection timeslots associated with a fault detection mode.
6. The radar device as claimed in claim 5 , wherein the transmitter circuit is configured to transmit the RF oscillator signal as a radar signal for target acquisition outside of the predetermined fault detection timeslots.
7. The radar device as claimed in claim 1 , wherein the receiver circuit has a high-pass filter or a bandpass filter, and
wherein the predetermined frequency offset lies within a passband of the high-pass filter or the bandpass filter.
8. The radar device as claimed in claim 1 , wherein the fault detection circuit is configured to:
determine, as the first phase, a phase of a first spectral component of the first down-converted reception signal, the first spectral component corresponding to the predetermined frequency offset,
determine, as the second phase, a phase of a second spectral component of the second down-converted reception signal, the second spectral component corresponding to the predetermined frequency offset, and
determine whether or not the hardware fault is present based on evaluating a comparison value between the phase of the first spectral component and the phase of the second spectral component, including determining that the hardware fault is present based on the comparison value satisfying a threshold value.
9. The radar device as claimed in claim 8 , wherein the first fault detection timeslot and the second fault detection timeslot are successive fault detection timeslots.
10. The radar device as claimed in claim 1 , wherein the first fault detection timeslot and the second fault detection timeslot are successive fault detection timeslots, and
wherein the fault detection circuit is configured to detect the hardware fault based on a comparison value between the first phase and the second phase exceeding a predetermined threshold value.
11. The radar device as claimed in claim 1 , wherein:
the transmitter circuit comprises a first transmitting path and a second transmitting path and is configured to transmit the first RF fault detection signal via one the first transmitting path and transmit the second RF fault detection signal via the second transmitting path,
wherein the receiver circuit is configured to receive the first RF fault detection signal as the first RF reception signal during the first fault detection timeslot, and receive the second RF fault detection signal as the second RF reception signal during the second fault detection timeslot.
12. The radar device as claimed in claim 1 , wherein:
the transmitter circuit is configured to transmit the first RF fault detection signal via a first transmitting path during the first fault detection timeslot and to transmit the second RF fault detection signal via a second transmitting path during the second fault detection timeslot following the first fault detection timeslot,
the receiver circuit is configured to receive the first RF fault detection signal as the first RF reception signal during the first fault detection timeslot and to mix the first RF fault detection signal with the RF oscillator signal in order to obtain the first down-converted reception signal, and to receive the second RF fault detection signal as the second RF reception signal during the second fault detection timeslot and to mix the second RF fault detection signal with the RF oscillator signal in order to obtain the second down-converted reception signal, and
the fault detection circuit is configured to:
during the first fault detection timeslot, determine, as the first phase, a phase of a signal component of the first down-converted reception signal that corresponds to the predetermined frequency offset,
during the second fault detection timeslot, determine, as the second phase, a phase of a signal component of the second down-converted reception signal that corresponds to the predetermined frequency offset, and
detect the hardware fault based on a difference between the first phase and the second phase satisfying a threshold.
13. The radar device as claimed in claim 1 , wherein the transmitter circuit has a transmitting antenna and the receiver circuit has a receiving antenna, and wherein the first RF fault detection signal and the second RF fault detection signal undergo crosstalk from the transmitting antenna to the receiving antenna for providing the first RF reception signal and the second RF reception signal to the receiver circuit, respectively.
14. The radar device as claimed in claim 1 , wherein the transmitter circuit and the receiver circuit are integrated in a common monolithic microwave integrated circuit (MMIC).
15. The radar device as claimed in claim 1 , wherein the RF signal conduction breakage defect is a solder joint defect.
16. The radar device as claimed in claim 1 , wherein the transmitter signal path includes:
a first signal path through which the RF oscillator signal is provided to an RF transmit terminal for transmitting the RF oscillator signal as a radar signal;
a second signal path, including a frequency shifter configured to shift the RF oscillator signal by the predetermined frequency offset to generate the first RF fault detection signal and the second RF fault detection signal, and provide the first RF fault detection signal and the second RF fault detection signal to the RF transmit terminal for transmission; and
a switch configured to:
couple, during the first fault detection timeslot, the RF oscillator signal to the RF transmit terminal for providing the first RF fault detection signal to the RF transmit terminal for transmission,
couple, during the second fault detection timeslot, the RF oscillator signal to the RF transmit terminal for providing the second RF fault detection signal to the RF transmit terminal for transmission, and
couple, outside of the first fault detection timeslot and the second fault detection timeslot, the RF oscillator signal to the RF transmit terminal for providing the RF oscillator signal to the RF transmit terminal for transmission.
17. The radar device as claimed in claim 8 , wherein the first spectral component and the second spectral component correspond only to the predetermined frequency offset.
18. The radar device as claimed in claim 1 , wherein the transmitter circuit is configured to transmit the first RF fault detection signal via a first transmitting path during the first fault detection timeslot and to transmit the second RF fault detection signal via a second transmitting path during the second fault detection timeslot following the first fault detection timeslot,
wherein the transmitter circuit is configured to transmit a third RF fault detection signal via the first transmitting path during a third fault detection timeslot and to transmit a fourth RF fault detection signal via the second transmitting path during a fourth fault detection timeslot following the third fault detection timeslot, wherein the third RF fault detection signal and the fourth RF fault detection signal have the predetermined frequency offset with respect to the RF oscillator signal,
wherein the receiver circuit is configured to:
receive a third RF reception signal associated with the third RF fault detection signal and mix the third RF reception signal with the RF oscillator signal in order to obtain a third down-converted reception signal, and
receive a fourth RF reception signal associated with the fourth RF fault detection signal and mix the fourth RF reception signal with the RF oscillator signal in order to obtain a fourth down-converted reception signal,
wherein the fault detection circuit is configured to:
determine a third phase of the third down-converted reception signal,
determine a fourth phase of the fourth down-converted reception signal,
determine a first difference between the first phase and the second phase,
determine a second difference between the third phase and the fourth phase,
determine a difference between the first difference and the second difference, and
detect the hardware fault based on the difference between the first difference and the second difference satisfying a threshold.
19. The radar device as claimed in claim 1 , wherein the transmitter circuit is configured to transmit a third RF fault detection signal during a third fault detection timeslot and to transmit a fourth RF fault detection signal during a fourth fault detection timeslot following the third fault detection timeslot, wherein the third RF fault detection signal and the fourth RF fault detection signal have the predetermined frequency offset with respect to the RF oscillator signal, the first RF fault detection signal, the second RF fault detection signal, the third RF fault detection signal, and the fourth RF fault detection signal being transmitted via a same transmitting path,
wherein the receiver circuit is configured to:
receive the first RF reception signal at a first receiving path,
receive the second RF reception signal at a second receiving path that is different from the first receiving path,
receive the third RF fault detection signal as a third RF reception signal at the first receiving path via antenna crosstalk coupling with the transmitter circuit, and mix the third RF reception signal with the RF oscillator signal in order to obtain a third down-converted reception signal, and
receive the fourth RF fault detection signal as a fourth RF reception signal at the second receiving path via antenna crosstalk coupling with the transmitter circuit, and mix the fourth RF reception signal with the RF oscillator signal in order to obtain a fourth down-converted reception signal,
wherein the fault detection circuit is configured to:
determine a third phase of the third down-converted reception signal,
determine a fourth phase of the fourth down-converted reception signal,
determine a first difference between the first phase and the second phase,
determine a second difference between the third phase and the fourth phase,
determine a difference between the first difference and the second difference, and
detect the hardware fault based on the difference between the first difference and the second difference satisfying a threshold.
20. The radar device as claimed in claim 1 , wherein the first fault detection timeslot and the second fault detection timeslot are different fault detection timeslots,
wherein the receiver circuit is configured to:
receive the first RF reception signal at a first receiving path,
receive the second RF reception signal at a second receiving path that is different from the first receiving path,
receive the first RF fault detection signal as a third RF reception signal at the second receiving path via antenna crosstalk coupling with the transmitter circuit, and mix the third RF reception signal with the RF oscillator signal in order to obtain a third down-converted reception signal, and
receive the second RF fault detection signal as a fourth RF reception signal at the first receiving path via antenna crosstalk coupling with the transmitter circuit, and mix the fourth RF reception signal with the RF oscillator signal in order to obtain a fourth down-converted reception signal,
wherein the fault detection circuit is configured to:
determine a third phase of the third down-converted reception signal,
determine a fourth phase of the fourth down-converted reception signal,
determine a first difference between the first phase and the third phase,
determine a second difference between the second phase and the fourth phase,
determine a difference between the first difference and the second difference, and
detect the hardware fault based on the difference between the first difference and the second difference satisfying a threshold.
21. A method for detecting hardware faults of a radar device, comprising:
generating an RF oscillator signal;
transmitting, by a transmitter circuit, a first RF fault detection signal derived from the RF oscillator signal, wherein the first RF fault detection signal has a predetermined frequency offset with respect to the RF oscillator signal;
receiving, by a receiver circuit, the first RF fault detection signal as a first RF reception signal via antenna crosstalk coupling with the transmitter circuit;
mixing the first RF reception signal with the RF oscillator signal in order to obtain a first down-converted reception signal;
transmitting, by the transmitter circuit, a second RF fault detection signal derived from the RF oscillator signal, wherein the second RF fault detection signal has the predetermined frequency offset with respect to the RF oscillator signal;
receiving, by the receiver circuit, the second RF fault detection signal as a second RF reception signal via antenna crosstalk coupling with the transmitter circuit;
mixing the second RF reception signal with the RF oscillator signal in order to obtain a second down-converted reception signal;
determining, at the predetermined frequency offset, a first phase of the first down-converted reception signal;
determining, at the predetermined frequency offset, a second phase of the second down-converted reception signal; and
detecting a hardware fault based on a difference between the first phase of the first down-converted reception signal and the second phase of the second down-converted reception signal,
wherein the hardware fault includes at least one RF signal conduction breakage defect in a transmitter signal path of a transmitter circuit or in a receiver signal path of a receiver circuit.
22. The method as claimed in claim 21 , wherein the first RF fault detection signal and the second RF fault detection signal are transmitted during predetermined fault detection timeslots, and the RF oscillator signal is transmitted as a radar signal during predetermined target acquisition timeslots.
23. The method as claimed in claim 21 , further comprising:
determining a first discrete spectral component of the first down-converted reception signal that corresponds to the predetermined frequency offset based on a Goertzel algorithm, wherein the first phase is a phase of the first discrete spectral component; and
determining a second discrete spectral component of the second down-converted reception signal that corresponds to the predetermined frequency offset based on the Goertzel algorithm, wherein the second phase is a phase of the second discrete spectral component.
24. The method as claimed in claim 23 , wherein the hardware fault is detected based on a comparison value between the first phase and the second phase exceeding a predetermined threshold value, the first RF fault detection signal and the second RF fault detection signal being transmitted in two successive fault detection timeslots.
25. The radar device as claimed in claim 18 , wherein the receiver circuit is configured to receive the first RF reception signal, the second RF reception signal, the third RF reception signal, and the fourth RF reception signal via a same receiving path.
26. The radar device as claimed in claim 20 , wherein the first RF fault detection signal and the second RF fault detection signal are transmitted via a same transmitting path.