Optimizing Satellite Communications with Adaptive and Phased Array Antennas

A new adaptive antenna array architecture for lowearth-orbit satellite ground stations is being investigated. These ground stations are intended to have no moving parts and could potentially be operated in populated areas, where terrestrial interference is likely. The architecture includes multiple, moderately directive phased arrays. The phased arrays, each steered in the approximate direction of the satellite, are adaptively combined to enhance the signal-to-interference-plus-noise (SNIR) of the desired satellite. The size of each phased array is to be traded-off with the number of phased arrays, to optimize cost, while meeting a bit-error-rate threshold. Also, two phased array architectures are being prototyped: a space-fed lens array and a reflect-array. If two co-channel satellites are in the field of view of the phased arrays, then multiuser detection techniques may enable simultaneous demodulation of the satellite signals, also known as space division multiple access (SDMA). We report on Phase I of the project, in which fixed directional elements are adaptively combined in a prototype to demodulate the S-band downlink of the EO-1 satellite.