Generation of Staircase Type Side Lobe Level from Linear Array Antenna Using Fast Fourier Transform

The paper describes the application of iterative fast fourier transform for generation of staircase type side lobe level (SLL) with a uniformly spaced linear array of isotropic antennas. Three examples have been presented, first with three fixed levels of SLL in decreasing order while moving away from the main beam, second with three fixed levels of SLL in increasing order while moving away from the main beam, third with three fixed levels of SLL in any prescribed order. The examples show that the method used is powerful enough to produce any number of fixed levels of SLL in any order according to the requirement. All the examples are simulated using 30 elements. The main advantage of this method is the speed as array factor is calculated using IFFT on excitation and excitation is obtained from applying FFT on array factor.