G/T of solid state and photonic array antennas

The G/T (gain over system noise temperature) on receive is particularly important for a photonic array, because the time shifters in the beamforming network are very lossy (due to high back-to-back conversion loss in the fiber optic delay line). The calculation of system noise temperature (noise figure) is straightforward when there is no taper in the combining network, (all the receive channels are identical). But if a taper is imposed to control the sidelobes, the computation is somewhat complicated by the fact that each channel contributes a different amount of loss to the signal and noise. The purpose of the present work is to examine this point with a simple analysis.<>