Noise Considerations for Wideband True Time Delay Photonic Beamformers

With the advent of new forms of true time delay wideband beamformers -both photonic and digital-the effect of noise within the beamformer channels must be taken into account As an example, in this paper, a multibeam photonic beamformer for a phased array working in receive mode using linear frequency modulated pulses is analyzed. A general expression is obtained showing the effect of the optical noise on the spatial antenna pattern and on the impulse response. The S/N (Signal to Noise Ratio) of the beamformer is examined with regard to both uncorrelated and correlated noise between channels.