In the past decades,time-delay line has been widely applied in amplifier,oscillator, decipherer,signal processing,radar and electronic countermeasures.Restricted by the aperture fill time of array,the conventional phased array antenna(PAA) only operates under the relatively narrow band signals.It is difficult to realize a high instantaneous bandwidth and a wide-angle beam-scanning,which makes it not suitable to more complex conditions and domains requiring high-performance.Optically controlled phased array antenna(OCPAA) with applied optical true time delay(OTTD) can remove the restriction by the aperture fill time of array.With the optically controlled beamforming network,OCPAA offers well-known advantages of high instantaneous bandwidth,low propagation loss,small- size and weight, immunity to electromagnetic interference(EMI),removing-capability,and squint free operation, so that it has become an important trend in the development of PAA.The paper mainly consists the design and measurement of fiber true time delay line in OCPAA,including the design and measurement of fiber true time delay line,the processing method of measurement data and the preliminary optimization of the measurement uncertainty.Firstly,the basic theory of the scanning of PAA and the time delay of the OTTD is introduced.
