Optimal null steering method in uniformly excited equally spaced linear arrays by optimising two edge elements

Mohammed, Jafar Ramadhan

doi:10.1049/el.2017.1405

Cited by 30 publications

(29 citation statements)

References 3 publications

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“…Recently, the feeding networks were made very easy and practically efficient by controlling only a certain number of the active elements rather than all of the array elements [6,7]. Other methods used a number of parasitic elements illuminated by a single active element to simplify the complexity issue of the feeding network.…”

Section: Introductionmentioning

confidence: 99%

Radiation Pattern Synthesis of Planar Arrays Using Parasitic Patches Fed by a Small Number of Active Elements

Mohammed¹,

Younus²

2020

Modern Printed-Circuit Antennas

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In this chapter, several planar array designs based on the use of a small number of the active elements located at the center of the planar array surrounded by another number of the uniformly distributed parasitic elements are investigated. The parasitic elements are used to modify the radiation pattern of the central active elements. The overall radiation pattern of the resulting planar array with a small number of active elements is found to be comparable to that of the fully active array elements with a smaller sidelobe level (SLL) at the cost of a relatively wider beamwidth and lower directivity. Nevertheless, the uses of only a small number of the active elements provide a very simple feeding network that reduces the cost and the complexity of the array. Simulation results which have been computed using computer simulation technology-microwave studio (CST-MWS) show that the sidelobe level of the designed array pattern with parasitic elements is considerably better than that of the similar fully active array elements. The proposed array can be effectively and efficiently used in the applications that require wider antenna beams.

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Section: Introductionmentioning

confidence: 99%

Radiation Pattern Synthesis of Planar Arrays Using Parasitic Patches Fed by a Small Number of Active Elements

Mohammed¹,

Younus²

2020

Modern Printed-Circuit Antennas

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“…Thus, the solutions were not optimum and there was a necessary need to search for an optimum solution for such an important scenario. Therefore, instead of a simple analytical method that was presented in [17], a more powerful method based on the genetic algorithm was proposed to find the optimal values of the amplitude and phase excitations for those electronically controllable edge elements with less computational time [20]. The method presented in [20] is further extended to obtain multiple wide nulls by properly selecting and optimizing the most effective elements in the array [21].…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, instead of a simple analytical method that was presented in [17], a more powerful method based on the genetic algorithm was proposed to find the optimal values of the amplitude and phase excitations for those electronically controllable edge elements with less computational time [20]. The method presented in [20] is further extended to obtain multiple wide nulls by properly selecting and optimizing the most effective elements in the array [21]. Wide nulls were also obtained by turning off some selected elements in the uniformly spaced linear arrays by means of binary genetic algorithm [22].…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, the mechanical null steering methods that are based on the controlling of the separation distance between the array elements were considered as an alternative and competitive solution to the electronic counterpart [23][24][25]. In [26], the author proved that the mechanical null steering made better patterns when compared with the electronic counterpart [20], by mechanically controlling the positions of the extreme elements while leaving all the electronic excitations including the edge elements constant.…”

Section: Introductionmentioning

confidence: 99%

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Sidelobe Nulling by Optimizing Selected Elements in the Linear and Planar Arrays

Mohammed¹,

Sayidmarie²

2019

Array Pattern Optimization

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Currently, there are significant interests in the antenna arrays that are composed of a large number of elements controlled by an appropriate optimizer for the next generation of wireless communication systems, where the massive multiple-inputs multiple-outputs (MIMO) systems are expected to play a major role in such systems. On the other hand, the interfering signals which are expected to rise dramatically in these applications due to the crowded spectrum represent a real challenging issue that limits and causes great degradation in their performances. To achieve an optimum performance, these antenna arrays should be optimized and designed to have maximum gain, narrow beam width, and very low sidelobes or deep nulls. Toward achieving this goal, the overall array performance can be either electronically controlling the design parameters, such as amplitude and/or phase excitations of the individual elements, or mechanically controlling the element positions. This chapter discusses techniques proposed for sidelobe nulling by optimizing the excitations and positions of selected elements in the linear and planar arrays.

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“…Generally, null steering has been performed by controlling the amplitude weighting [1] and/or phase weighting [2] of all element excitations or only a small subset of them [3][4][5] or even only two edge elements [6,7]. Although these methods guarantee effective cancelation of the interfering signals, an increase in the antenna array structures and feeding networks with respect to that of the uniformly excited arrays is unavoidable.…”

Section: Introductionmentioning

confidence: 99%

Thinning a Subset of Selected Elements for Null Steering Using Binary Genetic Algorithm

Mohammed¹

2018

PIER M

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Abstract-Generally, the null steering is performed by controlling the amplitude and/or phase weightings of all element excitations or only a small number of them. In such cases, a need for extra RF components such as variable attenuators and variable phase shifters with each element in the array is inevitable. In this paper, an alternative method is introduced where the null steering is performed by thinning (or turning off) only a small subset of the elements in the uniform linear arrays. To find an optimum combination of active (on) and inactive (off) elements, a binary genetic algorithm is used. In large arrays, the number of required nulls is much smaller than the total number of array elements, thus only a small subset of the array elements could be sufficient for producing the required nulls rather than optimizing all the array elements. By this way, a faster convergence speed of the optimizer and lowest peak sidelobe level can be obtained. The effectiveness of the proposed method with various subset configurations will be demonstrated and compared with some standard null steering methods.

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Optimal null steering method in uniformly excited equally spaced linear arrays by optimising two edge elements

Cited by 30 publications

References 3 publications

Radiation Pattern Synthesis of Planar Arrays Using Parasitic Patches Fed by a Small Number of Active Elements

Radiation Pattern Synthesis of Planar Arrays Using Parasitic Patches Fed by a Small Number of Active Elements

Sidelobe Nulling by Optimizing Selected Elements in the Linear and Planar Arrays

Thinning a Subset of Selected Elements for Null Steering Using Binary Genetic Algorithm

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