Design aspects and pattern prediction for phased arrays with subarray position errors

In modern array design, the antenna elements are often grouped into mechanical units such as printed antenna boards and mechanical subarrays/multipacks. This contributes to a more cost efficient manufacturing process and facilitates integration, handling, reuse and exchange of units, but it also makes the antenna element position errors correlated. Classical papers predict the statistical sidelobe level based on the assumption of uncorrelated errors [1],[2], but using this for the general case, the statistical sidelobe level is under estimated [3]. In this paper, the statistical sidelobe level for arrays with correlated position errors is predicted. Furthermore, rules of thumb relating antenna element position tolerances and mechanical array design to antenna array performance (sidelobe level) are given. Finally, array design aspects are discussed.