Optimizing Satellite Communications With Adaptive and Phased Array Antennas

Abstract – A new adaptive antenna array architecture for low-earth-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 in-terference is likely. The architecture includes multiple, moder-ately directive phased arrays. The phased arrays, each steered in the approximate direction of the satellite, are adaptively com-bined 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 ar-ray 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 tech-niques 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. I