According to the invention, a two-dimensional active antenna array, operating at a number of different frequencies, is used to achieve directivity in two orthogonal planes, thereby providing a more constrained beam "footprint". The array includes a larger number of amplifiers than a line array, thereby increasing the total power which can be combined in space, to further increase the power in the footprint. For transmission, each of the information channels at a different frequency is applied, as in the prior art, to a different power divider array, each of which may be on a separate board. Power-divided signal from each of the information signal channels is applied to an N-input, M-output power combiner arrangement or board, which combines the signals. Each N.times.M power combiner arrangement includes N.times.M nodes. Each node represents the junction or crossing of one input and one output signal transmission path. At each node, a power sample is extracted from the input signal, phase shifted, and coupled onto the output line. Each of the M output transmission lines therefore receives N phase-shifted samples of the input signals at their different frequencies, which combine to produce the desired output signal for application to the antennas of the array. In a particular embodiment of the invention, directional couplers provide the input signal sampling and the recombining. In another embodiment, resistance taps provide the sampling.