Large Phased-Array Antenna Multi-Beam Beamformers

"We are proposing assessing a novel approach towards forming beams using optical techniques. One advantage of our approach, which takes advantage of MEMS and detector arrays, is that the complexity of the beam forming circuitry scales as the square root ofthe size of the array. Another advantage is that we are leveraging the huge investment made in optics over the last few years by the telecommunications industry. Our ambition is to try to resolve all the problems presented in the RFP. Our preliminaryanalysis indicates that although DSP based beamforming has great value in applications with 10MHz bandwidths: technical risk, but also power and size issues would dominate a phased array design using those techniques when instantaneous bandwidths approach1500 MHz. We are focusing on the recieve beamformer because our assessment is that it is the most challenging aspect of an optical phased array. Key constraints are the SNR, dynamic range and multiple beams requirements. Several government agencies are facingmission challengees where communications or radar systems require very large phased arrays. A limiting issue is very often the elaborate beamforming network necessary. Offering a low cost high performance optically based beamforming network could enablea number of projects where Saraswati Associates could participate. In addition the commercial direct broadcast satellite industry is grappling with the challenge of deliver