Concentric Ring Array Synthesis for Low Side Lobes: An Overview and a Tool for Optimizing Ring Radii and Angle of Rotation

Yanki Aslan,Alexander Yarovoy,Antoine Roederer

doi:10.1109/access.2021.3109171

Yanki Aslan, Alexander Yarovoy + Show 1 more

Open Access

https://doi.org/10.1109/access.2021.3109171

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Abstract

A comprehensive review on the approaches for synthesizing low side lobe concentric ring array (CRA) antennas is given. An Iterative Convex Optimization (ICO) based array layout synthesis technique is proposed for peak side-lobe level (PSLL) minimization over a given circular field-of-view in steerable uniform-amplitude concentric ring array (UA-CRA) antennas. For a given number of rings and number of uniformly-distributed elements in each ring, the ICO algorithm optimizes the ring radii and angle of rotation, with possible constraints on the minimum element separation and largest array size. As compared to the existing UA-CRA synthesis techniques, the proposed method presents unique features as it combines the capability of optimization of angle of rotation of the rings and PSLL minimization for multiple elevation scan angles in a computationally-efficient and easy-to-solve procedure. Through numerical design examples, it is demonstrated how the ICO technique can be effectively used (i) to synthesize sparse UA-CRA topologies generating low PSLL steerable beams, and (ii) to assess and improve the PSLL suppression performance of various known optimization algorithms. Based on the UA-CRA topologies synthesized via competitive methods in the recent literature, a new set of improved array topologies are presented.

Highlights

Among the various types of planar arrays, the concentric ring array (CRA) antennas have gained more and more attention in modern communication and sensing systems [1]
Based on the analyses performed the following main observations can be made: (1) Using the optimized topologies in the literature as the initial topology in the proposed Iterative Convex Optimization (ICO) algorithm, the topology can be modified to achieve further suppression in the peak side lobe level (PSLL)
The proposed technique provides an efficient way to assess the optimality of the various types of algorithms in the literature

Summary

INTRODUCTION

Among the various types of planar arrays, the concentric ring array (CRA) antennas have gained more and more attention in modern communication and sensing systems [1]. The ICO technique can be combined with the existing analytical/global optimization methods to create a hybrid algorithm with extended features and improved optimality in the PSLL It can be directly used as a local optimizer to assess the optimality of different synthesis approaches presented in the literature and to improve their PSLL suppression performance when possible. The proposed ICO algorithm is used to assess the optimality of the recently presented uniform-amplitude CRA synthesis techniques in the literature in terms of the PSLL. CONVENTIONAL LAYOUT VS ICO ARRAYS As a reference, the dense 224-element CRA layout with dmin = 0.5λ, φn,1 = 0 ∀n ∈ {1, ..., N = 8} given in Fig. 2(a) is considered Using this as the initial topology, the proposed ICO procedure is applied. PSLL convergence for the 224-element CRA layout optimization in the ICO algorithm

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CONCLUSION