Optical techniques for signal distribution in phased arrays

A phased array is a form of microwave antenna in which the radiating aperture comprises a number of individual radiating elements. The relative amplitudes and phases of the currents at the elements determine the resultant radiation pattern. The operational use of phased arrays has been limited as a result of cost considerations. A solution to the problem of providing cost effective arrays will focus attention on the means of signal distribution within the array. A promising approach to the distribution problem is the use of fiber optic technology. The present investigation is concerned with the advantages of optics and the critical parts of the distribution requirements for a phased array. The transmitter reference signal is considered, taking into account intensity modulation, coherent schemes, and the distribution network. Attention is also given to the received signal, the components needed for an optically interfaced array, and experimental programs.