Array transmitter/receiver controlled by a true time-delay fiber-optic beamformer

We demonstrate a phased-array antenna controlled by a fiber-optic beamformer in true time-delayed transmit mode and in phase-delayed receive mode. The wavelength-tunable optical carrier propagating in a high-dispersion fiber realizes a true time-delay, with the steering direction set by a single voltage controlling the wavelength. The linear antenna is a sparsely-populated array with eight broadband spiral elements. The transmitter operates in 2-18 GHz frequency range over /spl plusmn/50/spl deg/ azimuth steering, and the receiver operates in 6-16 GHz frequency range over /spl plusmn/35/spl deg/ azimuth steering.>