Effects of Errors on the Side-Lobe Level of a Low-Side Lobe Array Antenna

摘要

This report examines the effects of array errors on the side-lobe distribution of a phased array. The statistical distribution of this side-lobe level is shown to be Rician. A set of universal curves which give the cumulative probability of the percent deviation of side-lobe levels from the designed values is plotted. The variance, which is normalized with respect to the designed side-lobe level, is used as a parameter for this family of curves. This variance is a function of both the array errors and the illumination function. It is shown that the illumination function can be approximated by the number of array elements. Values of variance as a function of array error are also plotted. With these curves, it is very easy to find the probability of the deterioration of the side-lobe level, if the array size and error distribution are known. The effect of correlated array error in a planar array is discussed. The variance due to this correlated error is a function of the array pattern of the subarray having this correlated error. (Author)