Abstract: A flat phased array antenna for reception of circularly polarized high frequency signals. The flat antenna array consists of a number of subarrays arranged in a matrix. In turn, each of the subarrays consist of individual antenna elements arranged in a matrix. In one embodiment, each subarray consists of four layers stacked one on top of the other. The top layer defines an array of miniature reception horns. Secured to the top layer is a second layer which constitutes the short-circuit plate of the antenna array. The short-circuit plate contains a plurality of through holes disposed about the surface of the circuit plate to permit passage of pairs of cylindrically shaped probes. The two remaining layers constitute the first power dividing layer and the second power dividing layer, respectively. Each of the layers includes transmission line waveguides.