The invention relates to a beam-forming network based on optical Butler matrices which are subjected to a series of modifications that are intended to: increase the number of possible beams generated by the matrix, exploit the intrinsic multi-beam capability thereof in a simple and immediate manner, provide the architecture with the ability to adjust the angular position of the possible beams, simplify the final design of the forming network significantly and provide the network with the ability to generate simultaneously determined phase fronts and the opposites of same. The invention also applies to optical matrix structures comprising fixed phase-shift/delay elements (such as Blass or Rotman matrices) and, in general, to other heterodyne forming architectures.