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In this paper, the authors propose to design thinned sparse planar array antenna in multiple planes using meta-heuristic optimization algorithm such as Teaching Learning-Based Optimization (TLBO) algorithm. The objective is to achieve the minimum value of side lobe level (SLL) in the radiation pattern in two vertical planes as well as in all vertical planes. The optimal positions of the isotropic antennas in the array are obtained having multiple optimization constraints such as total number of antennas in the array, aperture area and minimum inter-element spacing. The simulation results demonstrate that the proposed method is found to be relatively simpler but promising compared to the results reported using other competitive methods. [ABSTRACT FROM AUTHOR]

An efficient approach based on the combination of two-dimensional Woodward–Lawson analytical method and differential evolution optimization algorithm is developed for the synthesis of irregularly shaped radiation patterns based on four-dimensional planar arrays. Owing to the time-modulation of four-dimensional arrays, the ripples in the coverage area and the side-lobe levels are suppressed effectively. By combining the two-dimensional Woodward–Lawson method and differential evolution algorithm, the optimized time sequences and element excitations can be obtained. Radiation efficiency of time-modulated planar arrays also has been optimized and a significant improvement is achieved. Considering a practical application scenario where six-bit phase shifters are employed, the peak side-lobes have been suppressed significantly by employing the genetic algorithm. Numerical examples are presented to demonstrate the effectiveness and flexibility of the proposed approach. [ABSTRACT FROM PUBLISHER]

Synthesis of sum and difference patterns of a planar array is introduced in this article by means of a clustering algorithm. The whole array aperture is divided into several sub-arrays, which will reduce the cost and complexity of manufacturing the array antenna. The sub-array configurations and the corresponding sub-array weights are defined to minimize the maximum level of the side-lobes of the corresponding sum and difference patterns. Two kinds of arrays are considered here: in the first, the whole aperture is divided into several sub-arrays to get sum and difference patterns; in the other, the compromise difference pattern is obtained. Some numerical experiments are given to assess the feasibility and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

A mean variance mapping optimization algorithm for three types of antenna array synthesis examples is presented. Mean variance mapping optimization is based on the strategic transformation used for mutating the offspring built on mean variance of a certain dynamic population. The first set of examples is based on side-lobe suppression and null control by controlling element positions with mean variance mapping optimization under constraints to beam width. In the second group of examples, mean variance mapping optimization becomes an optimization tool to calculate the amplitude and phase values of antenna array elements to synthesize shaped beams. In the last set of examples, mean variance mapping optimization is used to mitigate the effect of failure elements on the pattern by recalculating the amplitude values of remaining elements. Additionally, a modification that provides a good balance between exploitation and exploration is applied to the mean variance mapping optimization algorithm to improve its stability and accuracy. The simulation results showed that the proposed mean variance mapping optimization is an effective and easy implementable technique for different antenna array synthesis problems. [ABSTRACT FROM AUTHOR]

In this article, the design of multiple radiation patterns from time-modulated linear antenna arrays is presented. As compared to conventional linear arrays in generating multiple patterns by switching among different phase distributions, the time-modulated linear arrays are capable of realizing more stringent requirements such as lower sidelobes for the multiple patterns. Moreover, the time-modulated linear arrays with pre-assigned amplitude distributions can be used to synthesize a greater number of desired patterns due to their additional degree of design freedom. Different excitations for multiple patterns are obtained through the differential evolution algorithm while keeping the sidebands minimized. Numerical examples of synthesizing several typical radiation patterns from time-modulated linear arrays are presented. [ABSTRACT FROM AUTHOR]

This paper proposes an effective approach based on the differential evolution (DE) algorithm for the synthesis of uniform amplitude thinned phased linear arrays. Two different measures are introduced in the algorithm for the constraint of the search ranges of the element spacing, and quantized phase excitations are also considered for array feeds with digital devices. Simulation results of several typical phased array problems are compared with those simulated by the real-coded genetic algorithm (RGA) to demonstrate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

An efficient search technique based on a touring ant colony optimization algorithm is presented for the shaped-beam pattern synthesis of a linear antenna array. The element excitations of equally spaced array and the element positions of uniformly excited array are determined to closely approximate the desired pattern. In the touring ant colony optimization algorithm, the frequency memory feature of tabu search is used. Illustrative examples of cosecant, flat-topped and pencil beam patterns are given to verify the validity and accuracy of the technique. [ABSTRACT FROM AUTHOR]

Ludwig distributions are a generalization of circular Taylor distributions that generate radiation patterns with wide-angle side lobe levels decaying faster than for Taylor patterns. In this paper we show that by means of an appropriate optimization technique the zeros of Ludwig patterns can be perturbed so as to improve or modify pattern and/or aperture distribution characteristics without altering the wide-angle decay behavior. The examples presented include footprint patterns, pencil beam patterns with individually controlled side lobe heights, footprint beams generated by real excitations, and pencil beam patterns with aperture distributions that are smoother than the original Ludwig distribution. [ABSTRACT FROM AUTHOR]