Beam steering array antenna controlled by optical wavelength

We developed a beam forming network (BFN) for an array antenna with 5 elements radiating 3 independently steerable beams, and measured the phase shift characteristics. The main part of the BFN is integrated as a single photonic integrated circuit (PIC) chip using birefringent Lithium Niobate (LN) waveguide. The phase distribution among the 5 element antennas is controlled by the wavelength tuning of an optical RF source. Highly linear phase shift characteristics with the sensitivity of 8.24 degrees/nm are achieved. By using 3 tunable optical RF sources allocated to different wavelength range, the PIC chip can generate feeding signals for 3 independently steerable beams.