Antenna device and radar device

1. An antenna device comprising:

a plurality of transmission antennas to radiate transmission signals; and

a plurality of reception antennas each to receive, as a reflected signal, each of the transmission signals radiated from the respective plurality of transmission antennas and then reflected by a target, and output a reception signal corresponding to the reflected signals, wherein

the plurality of reception antennas are arranged at regular intervals between two transmission antennas adjacent to each other among the plurality of transmission antennas, and a length between the two transmission antennas has a width obtained by adding an integral multiple of a length between each two of the plurality of reception antennas to a width obtained by dividing the length between each two of the plurality of reception antennas by a number of the plurality of transmission antennas.

2. The antenna device according to claim 1 , wherein

spacings between each two of the plurality of transmission antennas differ from each other, and

each of the spacings between each two of the plurality of transmission antennas has a width obtained by adding an integral multiple of the length spacing between each two of the plurality of reception antennas to an integral multiple of the width obtained by dividing the length between each two of the plurality of reception antennas by the number of the plurality of transmission antennas.

3. The antenna device according to claim 1 , wherein a length between a first transmission antenna included in the two transmission antennas and a reception antenna disposed so as to be adjacent to the first transmission antenna among the plurality of reception antennas is wider than the length between each two of the plurality of reception antennas, and a length between a second transmission antenna included in the two transmission antennas and a reception antenna disposed so as to be adjacent to the second transmission antenna among the plurality of reception antennas is wider than the length spacing between each two of the plurality of reception antennas.

4. The antenna device according to claim 1 , wherein each of the plurality of transmission antennas and the plurality of reception antennas is installed on a vehicle.

5. The antenna device according to claim 4 , wherein each of the plurality of transmission antennas and the plurality of reception antennas is installed on a windshield's edge portion of the vehicle, a rear window's edge portion of the vehicle, a pillar of the vehicle, a front bumper of the vehicle, or a rear bumper of the vehicle.

6. A radar device comprising:

a plurality of transmission antennas to radiate transmission signals;

a plurality of reception antennas each to receive, as a reflected signal, each of the transmission signals radiated from the respective plurality of transmission antennas and then reflected by a target, and output a reception signal corresponding to the reflected signals; and

a signal processor to coherently integrate the reception signals outputted from the plurality of reception antennas, on a basis of an arrangement of each of the plurality of transmission antennas and the plurality of reception antennas, and measure an angle of the target from a coherent-integration signal, the coherent-integration signal being a result of the coherent integration of the reception signals, wherein

the plurality of reception antennas are arranged at regular intervals between two transmission antennas adjacent to each other among the plurality of transmission antennas, and a length between the two transmission antennas has a width obtained by adding an integral multiple of a length between each two of the plurality of reception antennas to a width obtained by dividing the length between each two of the plurality of reception antennas by a number of the plurality of transmission antennas.

7. The radar device according to claim 6 , wherein

spacings between each two of the plurality of transmission antennas differ from each other, and

each of the spacings between each two of the plurality of transmission antennas has a width obtained by adding an integral multiple of the length between each two of the plurality of reception antennas to an integral multiple of the width obtained by dividing the length between each two of the plurality of reception antennas by the number of the plurality of transmission antennas.

8. The radar device according to claim 6 , wherein a length between a first transmission antenna included in the two transmission antennas and a reception antenna disposed so as to be adjacent to the first transmission antenna among the plurality of reception antennas is wider than the length between each two of the plurality of reception antennas, and a length between a second transmission antenna included in the two transmission antennas and a reception antenna disposed so as to be adjacent to the second transmission antenna among the plurality of reception antennas is wider than the length between each two of the plurality of reception antennas.

9. The radar device according to claim 6 , wherein the signal processor calculates an azimuth angle of the target or an elevation angle of the target from the coherent-integration signal.

10. The radar device according to claim 6 , wherein the signal processor generates a plurality of distance and speed signals including each of distance information about a distance to the target and speed information about a speed of the target, on a basis of the reception signals outputted from the plurality of reception antennas, coherently integrates the plurality of distance and speed signals on a basis of an arrangement of each of the plurality of transmission antennas and the plurality of reception antennas, and measures an angle of the target from a coherent-integration signal, the coherent-integration signal being a result of the coherent integration of the plurality of distance and speed signals.

11. The radar device according to claim 10 , wherein the signal processor incoherently integrates the plurality of distance and speed signals, and calculates each of a distance to the target and a speed of the target from an incoherent-integration signal, the incoherent-integration signal being a result of the incoherent integration of the plurality of distance and speed signals.

12. The radar device according to claim 6 , wherein the signal processor generates a plurality of distance and speed signals including each of distance information about a distance to the target and speed information about a speed of the target, on a basis of the reception signals outputted from the plurality of reception antennas, performs a signal regular interval process that converts the plurality of distance and speed signals into signals having regular signal intervals, performs a fast Fourier transform on the plurality of distance and speed signals having been subjected to the signal regular interval process, by which the plurality of distance and speed signals having been subjected to the signal regular interval process are coherently integrated, and measures an angle of the target from a coherent-integration signal, the coherent-integration signal being a result of the coherent integration of the plurality of distance and speed signals having been subjected to the signal regular interval process.

13. The radar device according to claim 6 , wherein the signal processor generates a plurality of distance and speed signals including each of distance information about a distance to the target and speed information about a speed of the target, on a basis of the reception signals outputted from the plurality of reception antennas, performs a signal regular interval process that converts the plurality of distance and speed signals into signals having regular signal intervals, performs a chirp z-transform on the plurality of distance and speed signals having been subjected to the signal regular interval process, by which the plurality of distance and speed signals having been subjected to the signal regular interval process are coherently integrated, and measures an angle of the target from a coherent-integration signal, the coherent-integration signal being a result of the coherent integration of the plurality of distance and speed signals having been subjected to the signal regular interval process.

14. The radar device according to claim 6 , wherein the signal processor generates a plurality of distance and speed signals including each of distance information about a distance to the target and speed information about a speed of the target, on a basis of the reception signals outputted from the plurality of reception antennas, performs a super-resolution process on the plurality of distance and speed signals, by which the plurality of distance and speed signals are coherently integrated, and measures an angle of the target from a coherent-integration signal, the coherent-integration signal being a result of the coherent integration of the plurality of distance and speed signals.

15. The radar device according to claim 14 , wherein the signal processor performs correction spatial averaging of a correlation matrix used to perform the super-resolution process, and performs a super-resolution process on the plurality of distance and speed signals using the correlation matrix obtained after the correction spatial averaging.

16. The radar device according to claim 14 , wherein the signal processor calculates a wave number used to perform the super-resolution process, on a basis of a number of the plurality of transmission antennas.

17. The radar device according to claim 6 , comprising a modulator to modulate each local oscillation signal using a code corresponding to each of channel numbers of the respective plurality of transmission antennas, by which a plurality of transmission signals are generated, and output each of the plurality of transmission signals to a corresponding one of the plurality of transmission antennas.

18. The radar device according to claim 6 , wherein each of the plurality of transmission antennas and the plurality of reception antennas is installed on a vehicle.

19. The radar device according to claim 18 , wherein each of the plurality of transmission antennas and the plurality of reception antennas is installed on a windshield's edge portion of the vehicle, a rear window's edge portion of the vehicle, a pillar of the vehicle, a front bumper of the vehicle, or a rear bumper of the vehicle.