Measured performance of a Ku-band multibeam high-power phased-array

Phased-array antenna systems are receiving increased attention for satellite applications due to their ability to form multiple beams, to provide flexible beam power-sharing through distributed amplification, and to rapidly reconfigure and reposition beams. The drawbacks to phased arrays have historically been related to mass and the performance uniformity required for a large number of elements. The advent of monolithic microwave integrated circuits (MMICs), and their natural applicability to arrays, has helped eliminate these concerns. With phased arrays, RF power may be combined in space by distributing power amplification directly behind the radiating element. This allows the beam-forming matrix (BFM)-which may include signal control circuitry such as MMIC phase shifters-to be incorporated in a lightweight transmission medium. The resultant antenna configurations have the potential for dramatic reductions in mass, while providing increased satellite flexibility and capacity. A number of advanced concepts employing active phased arrays have been investigated and the utility and applicability of phased arrays have been demonstrated through an evolutionary series of hardware development programs. This paper discusses the culmination of one such program-a Ku-band high-power multiple-beam phased array. The procedures and results of the laboratory calibration are summarized, and the subsequent radiation pattern predictions and measurements are presented.<>