Title:
MEASURING APPARATUS FOR DIRECTION
Document Type and Number:
Japanese Patent JP2611655
Kind Code:
B2
Abstract:
PURPOSE: To measure the direction with good accuracy with a comparatively simple constitution without precisely measuring the amplitude, the phase, the time and the like of a received signal.
CONSTITUTION: In a state that the received phase difference between receiving antennas 1, 2 is changed periodically by variable phase shifters 3, 4 under control of a phase controller 11, outputs, on one side, of power distributors 5, 6 are synthesized by a sum-signal synthesizer 7, and the other output of the power distributor 5 and the other output of the power distributor 6 are inverted by a 180°-phase shifter 8 so as to be synthesized by a difference-signal synthesizer 9. A phase detector 10 detects a timing at which the polarity of the phase difference between a sum signal and a difference signal is inverted, and a direction operation device 12 finds the arrival direction of radio waves by using the phase controlled value of the phase controller 11 at the detected phase- difference inversion timing.
Inventors:
Shoichiro Kawamura
Application Number:
JP9377394A
Publication Date:
May 21, 1997
Filing Date:
April 07, 1994
Export Citation:
Assignee:
NEC
International Classes:
G01S3/48; (IPC1-7): G01S3/48
Domestic Patent References:
| JP63223584A | ||||
| JP32688A |
Attorney, Agent or Firm:
Hachiman Yoshihiro