The gain-to-noise-temperature (G/T) of a seven antenna elements based L-band conformal antenna array for a low earth orbit (LEO) satellite is studied. The optimized G/T performance is achieved by switching on and off the related antenna elements and beamforming based on the visible angle of a geostationary equatorial orbit (GEO) satellite from a LEO satellite. The G/T of the array with beamforming is achieved above -19 dB/K for θ range from 0o to 90o.