An antenna system has multiple antenna feed elements combined in a number of element sets independently controlled to provide a beam of a variable size. Multiple input power dividers are provided for dividing an input signal, and multiple phase controllers are respectively connected to outputs of the power dividers for producing a plurality of phase-shifted signals having prescribed phases. The phase-shifted signals are supplied to respective inputs of a hybrid matrix. Predetermined outputs of the hybrid matrix are connected to summation circuitry for providing in-phase power summation of signals produced at these outputs. The antenna elements in at least one of the element sets are controlled by a sum signal produced by the summation circuitry. The other element sets may be controlled by respective output signals of the hybrid matrix.