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In this paper, the problem of array pattern synthesis is considered by developing two array response control algorithms. The devised two algorithms build on the basis of the accurate array response control (A2RC) approach, and both of them have closed-form solutions and low computational complexities. More specifically, the first proposed algorithm realizes multi-point array response control from an any given weight vector, and the second algorithm modifies the first one by avoiding the possible beam axis shift. The proposed two algorithms are able to control array responses accurately under the conditions of independence on steering vectors. By applying the first and the second array response control algorithm, two effective pattern synthesis methods for focused patterns and shaped patterns are devised, respectively. Representative examples are presented to demonstrate the performance of the proposed algorithms in array response control and pattern synthesis.

This letter presents a rotation-based optimization method for pattern synthesis of subarrayed phased arrays. In order to keep a good beam scanning ability at different steering angles, the optimization problem is reasonably defined where the objective is taken as minimizing the maximum sidelobe level at a series of steering angles, and both the arrangement variables and the scanning variables are optimized simultaneously. The mutual coupling of the iteratively rotated arrays is rigorously considered in the synthesis. In order to solve the synthesis problem effectively, the design sensitivities are derived analytically and the synthesis is actualized by using a gradient-based algorithm. Typical examples, with considering different regular subarray configurations and the state-of-art irregular subarray configurations, are provided to validate the effectiveness of the proposed approach.

In many practical applications, the antenna arrays are not accurately implemented as desired, resulting in the degradation of sidelobe level. This letter proposes a robust pencil beam pattern synthesis (PBPS) algorithm that is adaptive to the uncertainties of array position. The proposed algorithm, first, sets up the position-variation-related PBPS optimization problem, and then rewrites the position-related parameter, i.e., the array factor, into a high-order Taylor expansion with respect to the array position variation. Thereafter, an iterative processes are designed to estimate the position variation. Finally, the optimal array excitation is calculated by solving the related PBPS problem, in which the estimated array position is used. Simulations with both isotropic element pattern and active element pattern are carried out and the results are compared with the results achieved from the existing work to validate the superiority of the proposed algorithm.

This letter proposes a method based on primary-dual iteration to address the array pattern synthesis problem of minimizing the peak sidelobe level (PSL) under the constraints of controlled mainlobe ripples and dynamic range ratio (DRR) of current excitations. Especially, when DRR = 1, the phase-only beampattern synthesis problem is solved. Simulation examples are presented to verify the effectiveness of the proposed method in terms of PSL and DRR.

In this letter, a new algorithm is presented for synthesizing large linear and planar arrays. To reduce the system cost and implementation complexity, the large array is partitioned into multiple disjoint subarrays and is only weighted at subarray level. By the approximation of the optimization objective, the pattern synthesis problem is first formulated as a weight matching problem. Subsequently, a clustering methodology named $K$ -means approach is adopted to solve this problem. The proposed algorithm can produce a good-shaped pattern, which has lower peak sidelobe level than that synthesized by the state-of-the-art method. Numerical results demonstrate the effectiveness of the proposed algorithm.

One of the ultimate targets of array pattern synthesis is to maintain the mainbeam while suppressing the peak sidelode level (PSLL) within a smaller aperture size. The mainbeam gain proportionally increases with the aperture size, whereas the PSLL is uncorrelated approximately. This regular is useful for adjusting the array pattern as changing the aperture size. However, when the mutual coupling effect among the coupled array elements is considered, for some kinds of nonuniform arrays, e.g., the concentric ring array or the concentric elliptical array (CEA), the PSLL property would change significantly when the same array arrangement with different aperture sizes is used. On the purpose of both the PSLL suppression and the aperture reduction, this letter presents a pattern synthesis approach of real coupled CEAs. The form of elliptic ring is mainly introduced for the aperture reduction, and the ellipse-axis ratio, together with the ring radii and the position of each array element along the elliptic rings, are optimized simultaneously for the PSLL suppression. Typical examples are provided to validate the effectiveness of the synthesis approach. This approach also gives an alternative way for the adjustment of real coupled arrays after the theoretical synthesis.

This letter proposes a new power gain pattern synthesis-based (PGPS-based) algorithm for maximizing the minimum array power gain in a wide-beam mainlobe via linear programming. The existing PGPS-based algorithm has been proved to outperform the existing shaped beam pattern synthesis based (SBPS-based) algorithms. However, its optimal solution to the PGPS problem can only be obtained via iterative procedures and its convergence cannot be theoretically guaranteed. One disadvantage of this nonconvergence is that the desired sidelobe level (SLL) might be unobtainable. This letter reformulates the original PGPS problem and transforms it into an approximately equal convex form. As a result, the convergence of the proposed algorithm is ensured and the desired SLL can always be obtained. Moreover, the proposed algorithm can accelerate the computational time. Its performance is assessed with HFSS simulated data by comparing it with the existing PGPS-based algorithm and the SBPS-based algorithms.

Autocorrelation matching method is proposed for phase-only synthesis of power pattern of linear antenna arrays. This method is based on equating the autocorrelation coefficients of an array having given amplitude of excitations to those of a previously designed amplitude-phase array. Some examples are brought to verify the effectiveness of the proposed method for both pencil-beam and shaped beam patterns.

Numerical pattern synthesis (NPS) algorithm based on adaptive array theory is an effective spatial power pattern synthesis method for antenna arrays. In this letter, instead of using the artificial interferences weighted on the total power pattern in the conventional NPS algorithm, a generalized two-dimensional (2-D) NPS algorithm is proposed in which two weighting functions are assigned to control the copolarization and cross-polarization patterns, respectively. The weighting functions are iteratively updated until both the sidelobe and cross-polarization levels reach their prescribed ones. Two numerical examples for synthesizing the patterns of a linearly polarized planar array and a circularly polarized cylindrical array are provided to validate effectiveness and advantages of the proposed generalized 2-D NPS algorithm.

This letter addresses the problem of phase-only antenna beampattern synthesis. With the given magnitudes of the weight vector, we introduce a scaling factor to accurately represent the shape constraints on both the mainlobe and sidelobe regions. Moreover, we derive an iterative optimization method to solve the resultant optimization problem efficiently. The performance of the proposed method is demonstrated via numerical examples.

In this letter, a modified differential evolution (DE) based on harmony search algorithm is developed for the linear aperiodic array synthesis. By adding the parameter selection strategy into the classic differential evolution, the modified DE combines the good local search capability of the classic DE and the great search diversity of harmony search algorithm. The pattern optimization simulations of the linear aperiodic array verify that it converges faster and requires less computation.

This letter proposes an optimal difference pattern synthesis with polarization control ability for arbitrary arrays. The joint synthesis of the polarization and spatial power patterns are formulated as a convex optimization form that can be efficiently solved by existing numerical methods. The proposed synthesis method, which has no limitation on the array geometry and element pattern, is flexible and applicable to arbitrary arrays. Two typical examples, the linear arrays for circular polarization synthesis and the cylindrical arrays for elliptical polarization synthesis, are presented to testify the potentiality of the proposed method.

An improved synthesis procedure is presented in this letter for the design of waveguide slot arrays directly integrated on the substrate of the exciting microstrip line. To take into account the smallness of the waveguide height, the standard shunt-admittance model usually adopted for the single radiating slot is properly modified into an improved T-network model. Accordingly to this choice, a two-step synthesis procedure is developed to accurately determine the radiating slots' parameters. Experimental validations are discussed for the design of an 8-GHz linear array with a -20-dB Taylor pattern.

A novel neural-network (NN)-based technique for antenna array synthesis and a prototype of antenna array designed using it are presented. This technique is able to calculate the voltages that must be applied to the radiating elements considering all the physical properties of each element of the array and the coupling effects between all of them.

The synthesis of unequally spaced large arrays is computationally unapproachable without using an optimization technique. In complex structures, gradient implementations converge to local minima and cannot be used to obtain a desired solution. Thus, global search methods are necessary to get specific design characteristics. In this letter, we propose the ant colony optimization (ACO) as an useful alternative in the thinned array design, using the sidelobe level (SLL) as the desirability parameter. Some examples have been proposed and solved to demonstrate the functionality of this technique for both linear and planar arrays

Synthesis of uniform linear arrays by using the orthogonal method is presented. Composing functions similar to that of Woodward-Lawson technique are used. In Woodward-Lawson technique, sampling of the desired pattern is made. In this letter, instead of sampling, the orthogonal method is applied. The number of composing functions can be the same as or different than the elements of the arrays. Also, the progressive phase of each function can be derived in several ways. Numerical examples for the synthesis of different array patterns are presented, and the results show the usefulness of the method.