G/T of multi-segment active arrays - dependence on array configuration

A formulation for general active array optimization is proposed, integrating front end elements such as low noise amplifier, phase shifter, and arbitrary feed networks. A generalized G/T formulation is discussed for active arrays. G/T is the antenna gain over effective system temperature, and is directly related to the signal-to-noise ratio at the system output (Lee, J.J., IEEE Trans. Antennas and Propag., vol.41, no.2, p.241-4, 1993). Tradeoff between module gain/size, feed losses, and amplifier gains/noise figures and their effect on the G/T and SNR of different arrays is shown.