Optically controlled phased-array antenna using wavelength-selective true time delay

A novel all-optical tunable optical delay line device is used as a true-time-delay generator for squint-free beam steering in optically-controlled microwave phased-array antennas. The mapping of optical wavelength to the microwave beam direction permits a hardware efficient architecture for the optical control unit that can easily scale to large aperture antenna arrays. The performance of a complete optically controlled phased array antenna system employing such single-chip time-delay devices is reported. Extension to two-dimensional antenna arrays with independent control of azimuth and elevation by using mid-stage optical wavelength conversion is proposed and demonstrated. An optical true-time-delay steered two-element X band antenna was assembled to verify the wide instantaneous bandwidth operation.