Patent ID: 11933907
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A direction detection device for detecting a received-wave arrival direction of a received wave, the arrival direction of the received wave being defined by an AZ angle and an EL angle, the direction detection device comprising:
three or more antennas for receiving the received wave, the three or more antennas including a first combination of any two of the three or more antennas and a second combination of any two of the three or more antennas, wherein the three or more antennas are arranged linearly;
an intensity difference imparting unit configured to impart different intensity differences depending on the received-wave arrival direction to intensities of the received wave to be received at the antennas;
a detector configured to detect:
a first intensity difference between the any two of the three or more antennas in the first combination of the received wave to be received at the antennas, and
a second intensity difference between the any two of the three or more antennas in the second combination of the received wave to be received at the antennas;

a storage unit storing:
a first intensity difference table having a plurality of first cells each identified by an AZ angle and an EL angle, and in which an intensity difference between the any two of the three or more antennas in the first combination is set in each of the first cells, and
a second intensity difference table having a plurality of second cells each identified by an AZ angle and an EL angle, and in which an intensity difference between the any two of the three or more antennas in the second combination is set in each of the second cells;

an extractor configured to extract:
from the first intensity difference table stored in the storage unit, a plurality of first candidate cells corresponding to the first intensity difference detected by the detector, and
from the second intensity difference table stored in the storage unit, a plurality of second candidate cells corresponding to the second intensity difference detected by the detector; and

a comparator configured to compare AZ and EL angles associated with the first candidate cells with AZ and EL angles associated with the second candidate cells to acquire cells which match one another, wherein the AZ and EL angles corresponding to the acquired cells are a detection result,
wherein provision of different intensity differences according to the arrival direction of the received wave by the intensity difference imparting unit is due to at least one of:
(i) the intensity difference imparting unit having a non-uniform shape in three-dimensional space;
(ii) the intensity difference imparting unit having a non-uniform structure in three-dimensional space;
(iii) the intensity difference imparting unit having a material that changes an electrical characteristic of the received wave; and
(iv) the three or more antennas being circularly polarized, and elements of the circularly polarized antennas having spatially non-uniform gains.