NULL SYNTHESIS OF SCANNED LINEAR ARRAY ANTENNA WITH MINIMUM SIDE LOBE LEVEL AND FIXED DYNAMIC RANGE RATIO USING ITERATIVE FAST FOURIER TRANSFORM

This paper presents a method based on iterative fast fourier technique for placing nulls in prescribed directions by amplitude-only control method in the radiation pattern of scanned linear array of uniformly spaced isotropic antennas with fixed dynamic range ratio of amplitude distribution and minimum peak side lobe level. Two examples have been presented, one with 20 isotropic antennas for placing two nulls and another with 22 isotropic antennas for placing wide null. Dynamic range ratio in both the cases has been fixed at 4.0.The method uses the property that for a linear array with uniform element spacing, an inverse Fourier transform relationship exists between the array factor and the element excitations.