Design of Wideband and Wide-Scanning Hybrid Analog–Digital Subarrayed Array Based on Amplitude Disorder Model

Subarraying techniques are promising for achieving performance and cost tradeoffs in the design of a hybrid analog–digital array. However, previous approaches have paid little attention to the wideband and wide-angle scanning performance during the subarray synthesis, which faces a more stringent challenge due to excessive performance evaluation dimensions. This article addresses the design of a physically contiguous hybrid analog–digital array with wideband and wide-scanning performance. First, we construct an excitation matching problem and present the theoretical derivation. Second, leveraging two physical conditions, i.e., the contiguous subarray arrangement and bucket effect of the azimuthal scanning performance to introduce feasible representations and relaxations, we obtain an index, namely, weighted distance metric (WDM) for the characterization of subarray configurations with wideband and wide-scanning performance, and establish an amplitude disorder model (ADM) for optimizing subarray configurations. Third, the K-means method is adapted to search for the optimal subarray configuration efficiently. Finally, two methods are introduced, namely, the analytical phase (AP) and the convex optimization method, to achieve fast beamforming and better control of beam performance, respectively. The numerical results show that the proposed method has advantages in achieving better wideband and wide-scanning performance, with no restrictions on array shapes and cluster ratios compared to state-of-the-art methods.