US 7,248,216 B2Granted

Calibration apparatus and method for array antenna

AssigneeFujitsu Limited

InventorsChiyoshi Akiyama, Toshio Kawasaki, Tomonori Sato

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Abstract

The present invention relates to a calibration apparatus for an array antenna having a plurality of antenna elements. The calibration apparatus comprises a conversion unit detecting a calibration signal from an output of a transmission unit to convert the detected calibration signal into a predetermined reception radio frequency and outputting the converted calibration signal together with a reception main signal to a reception unit, a detecting unit detecting the calibration signal from an output of the reception unit for each of the antenna elements to obtain a relative phase difference between the calibration signals, and a phase correcting unit correcting a phase difference with respect to one of or both a transmission main signal and a reception main signal based on the obtained relative phase difference. This configuration can eliminate the need for a radio transmitter-receiver dedicated to a calibration signal, thus facilitating the calibrations.

Claims18

Dependent claims

A calibration apparatus for an array antenna having a plurality of antenna elements, comprising:

calibration signal producing means for producing a calibration signal for each of said antenna elements;
transmission means for outputting, to said antenna element, said calibration signal produced by said calibration signal producing means together with a transmission main signal at a predetermined transmission radio frequency;
reception means for receiving a reception main signal with a predetermined reception radio frequency from said antenna element;
calibration signal detection/frequency conversion means for detecting said calibration signal from the output of said transmission means to convert the detected calibration signal into a predetermined reception radio frequency and for outputting the converted calibration signal together with said reception main signal to said reception means;
relative phase difference detecting means for detecting said calibration signal from an output of said reception means for each of said antenna elements to obtain a relative phase difference between said calibration signals;
and
phase correcting means for correcting a phase difference with respect to one of or both said transmission main signal and said reception main signal on the basis of said relative phase difference obtained by said relative phase difference detecting means.

4 more elements

Dependencies are inferred from the claim text.