A Novel Algorithm in a Linear Phased Array System for Side Lobe and Grating Lobe Level Reduction with Large Element Spacing

In the phased arrays the side lobes level (SLL) level is main problem which causes waste of energy or saturation of the receiver in the case of presence of the strong spatial blockers. In this paper, a weighting method was first used to reduce the level of SLL. However, this method increased the beam width and reduced resolution, which is not suitable for track applications. In next step hoping to increase the resolution, the distance between the antennas increased. But in this way, grating lobes appeared in the final beam. In fact, the main idea of the article is to solve this problem. It is shown that for a linear 11-element phased array system with up to 180° scan angle for simultaneously beam-forming and null-steering a resolution of 10 degrees was obtained for the amount of difference between desired beam and null points. The proposed system reduces the grating lobes to below -11.6 dB.