Adaptive Beamforming Based On Subarray Partition

Phased array radars has found wide applications in military fields, in order tomeet the increasing need of high-resolution measurements in range and angle, largeaperture antennas is been used. Large phased array antennas are commonly consistedof huge amount of antennas units, to realize a full digital beamforming will results in alarge hardware equipment and large hardware expense. Thus adaptive beamforming atsubarray level is adopted to reduce the total cost and computational complexity.In this dissertation, the general adaptive antenna system model and arrayreceiving narrow signal model has been investigated. Sample matrix inversionalgorithm, recursive least square algorithm, and least mean square algorithm have beenintroduced and simulated. In succession,1-dimension and2-dimension configurationarrays have been studied both in adaptive digital beamforming at array level andsubarray level. Array factor for linear array and planar array have been given and threesubarray configuration methods are studied in case of the narrowband signal model,including regular configuration subarray, irregular configuration subarray andoverlapping subarray. Simulated results have shown the different performance forregular configuration subarray and irregular configuration subarray. The reason forgrating lobes and grating nulls has been studied. For the rise of sidelobe in irregularconfiguration subarray, a method of equal noise power has been adopted to lower thesidelobe level and signal to noise ratio. The simulated experiments prove the validityof ADBF at subarray level for both linear array and planar array.