Novel integrated optical beam former for phased-array antennas

We present the theoretical investigation, including design criteria, of a new optical beam former for phased-array active antennas. The device is formed by a Z-cut LiNbO3 channel-planar composite waveguide, an array of interferometric modulators and a linear microlens array. The basic element of the new architecture is the array of Mach-Zehnder Ti:liNbO(3) intensity modulators having asymmetric coplanar-strip traveling-wave electrodes in which a relatively thick SiO2 buffer layer is utilized to reduce the phase velocity mismatch between the microwaves and optical waves. A comparison with other optical and electronic architectures already proposed showed a number of significant advantages. In particular, our device can be used in multichannel optical computing systems as well as in optical communication and RF signal processing systems allowing to overcome severe frequency limitations typical of devices reported in literature since it can work at frequencies greater than 30 GHz. So the very large transmission rate typical of the optical fiber communication systems may be conveniently exploited.