Controlling the nullwidth in adaptive arrays by non-uniform spacing

The performance of an 11-element adaptive array was investigated for uniform and nonuniform spacing. It is shown that large nonuniform spacing controls a tradeoff operation between the nullwidth and the side null level (SNL). Large nonuniform spacing gives better performance than using Chebyshev coefficients as shown in an example where the SNL in the two arrays considered equals -0.92 dB, while the nullwidth in the Chebyshev array equals 0.145 and the nullwidth using large unequal spacings equals 0.075 (which is about half the nullwidth of the Chebyshev array).<>