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Title:
RADIO WAVE DIRECTION DETECTING DEVICE
Document Type and Number:
Japanese Patent JP3039530
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To reduce calibration signal cables for transmitting calibration signals to antennas side.
SOLUTION: Duplexers 2 (2-1 through 2-m) selectively outputting reception signals and calibration signals are provided on omnidirectional antennas 1 side receiving incoming waves, respectively. Receivers 4 (4-1 through 4-m) receive the signals from the antennas 1 side via transmission cables 13 (13-1 through 13-m) and circulators 3 (3-1 through 3-m). A calibration signal generator 8 outputs calibration signals Sc to a distributor 9 in response to the instruction signal C1 from a calculator 5. Circulators 3 send the calibration signals distributed by the distributor 9 to the antennas 1 side via transmission cables 13. The duplexers 2 extract the calibration signals sent via the transmission cables 13 with the circulators 3 and send back the calibration signals to the receivers 4 side via the same transmission cables 13.


Inventors:
Terasawa, Nobuo
Application Number:
JP1998000220334
Publication Date:
May 08, 2000
Filing Date:
August 04, 1998
Export Citation:
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Assignee:
NEC CORP
International Classes:
G01S3/48; G01S7/285; G01S7/40; (IPC1-7): G01S3/48; G01S7/285; G01S7/40
Attorney, Agent or Firm:
京本 直樹 (外2名)



 
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