Photonics for airborne phased array radars

In future generation phased array radars, signal distributions will have to fulfil strict performance criteria. These include high isolation from both electromagnetic interference and crosstalk between module or subarray feeds with increased instantaneous bandwidths, dramatic reduction in size and weight with respect to current radars, and performance compatible with growing requirements such as low phase noise and high dynamic range. Photonics and microwave technologies offers new opportunities for controlling many thousands of array elements together with handling the wide bandwidth of shared aperture antennas. Photonics technologies will provide an interconnect solution for future airborne phased array radar antennas, which have conformality, bandwidth, EMI immunity, size,and weight requirements increasingly difficult, if not impossible, to meet using conventional electrical interconnect methods. Future system requirements are reported together with results of newly developed high performance wideband analog microwave links and of demonstrated approaches for true time delay architectures.