PHASED ARRAY ANTENNA HAVING INTEGRAL CALIBRATION NETWORK AND METHOD FOR MEASURING CALIBRATION RATIO THEREOF

摘要

A phased antenna arrangement and a method for estimating the calibration ratio of an active phased antenna having a plurality of phased array antenna elements are described. The phased antenna arrangement includes a plurality of antenna elements, a plurality of receiving channels, an injection unit for injection of calibrating signals into the receiving channels, a point RF-source, located in a far field zone, a distance measurement unit, an amplitude and phase measurement unit and a data processing unit. The method comprises injecting an internal calibrating signal having a known amplitude and phase to each antenna element. An external calibration signal from a stationary RF-source is sequentially injected to all of the phased array antenna elements so that different phases of the external calibration signal arrive at each of the antenna elements. The differences in phases of the external calibration signal reaching the antenna elements are compensated so as compute an effective signal amplitude that would reach all of the antenna elements at zero phase difference. Calibration ratio is calculated as the ratio between the amplitude of the internal calibrating signal to the effective signal amplitude of the external calibration signal.