Failure mitigation of semi active multi beam antenna array for portable surveillance radar using genetic algorithm

Multi beam antenna arrays are extensively used for 3D surveillance radar, providing a shaped beam in elevation and multiple beams in receive. Semi active multibeam antenna system employs 18 TR modules in elevation, feeding 18 linear arrays. The TR modules feed the 18 linear arrays in uniform amplitude and with required phase distribution in elevation to form the shaped beam and also steers the stack of beams in elevation. The required coverage pattern in transmit is attained through the phase alone synthesis. As the number of TR modules is very low and there is no amplitude control using the TR modules in transmit, failure of one TRM will prove catastrophic as far as radar coverage is concerned. Using genetic algorithm, phase only synthesis is used to mitigate the failure of the TRM, by loading the new synthesized phase values using beam steering computer while the radar is in operation. This paper details how genetic algorithm has been effectively utilized to mitigate the TR module failure of electronically steered portable surveillance radar.