Development a New Array Factor Synthesizing Technique by Pattern Integration and Least Square Method

Alijani, Mohammad G. H.; Neshati, Mohammad Hassan

doi:10.1109/tap.2018.2871715

Cited by 19 publications

(11 citation statements)

References 10 publications

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“…By sampling the desired pattern at these points, a system of equations is derived in which the exciting coefficients, a i , are unknown. 14,15…”

Section: Problem Formulationmentioning

confidence: 99%

“…Based on Nyquist sampling theorem, the given condition in Equation (7) have to be satisfied, 14,16 in which d max is maximum value of d i , i = 1, 2, …, M and d max is chosen by designer.…”

Section: Problem Formulationmentioning

confidence: 99%

“…In the above equation, vector z 0 contains eigenvalue; A l and A f are obtained from A by deleting its last and first column, respectively. Since, A l and A f are nonsquare matrix, instead of Equation (13), a closed form equation given by (14) is obtained to find eigenvalues of A. 18…”

Section: Problem Formulationmentioning

confidence: 99%

See 2 more Smart Citations

A new noniterative method for pattern synthesis of unequally spaced linear arrays

Alijani

Neshati

2019

Int J RF Microw Comput Aided Eng

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In this article, a new noniterative beam shaping method is introduced to synthesise array factor (AF) of an unequally spaced linear array (UESLA). The proposed method is based on eigenvector decomposition of sampled data matrix of a given pattern. Using matrix analysis, the eigenvalues and their corresponding eigenvectors of the sampled matrix are determined. It is shown that the eigenvalues and eigenvectors of the sampled matrix are related to the locations and complex excitation coefficients of the array elements. According to the concept of generalized eigenvalue concept, the solution of locations and excitation coefficients is derived using least square method. In order to reduce the number of array elements, singular value decomposition is applied to obtain a low ranked matrix using rejection of nonzero eigenvalues. Using the approximated sampled matrix, the excitation and locations of the optimized array elements are calculated. A few comprehensive examples are investigated to verify the accuracy of the proposed method and the obtained results are compared with those of an equally spaced linear array (ESLA).It is shown that the total number of array elements in an UESLA is less than that of ESLA, which is the most advantage of the introduced method in AF synthesis. K E Y W O R D Santenna array, array factor synthesis, unequally spaced linear array

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“…By sampling the desired pattern at these points, a system of equations is derived in which the exciting coefficients, a i , are unknown. 14,15…”

Section: Problem Formulationmentioning

confidence: 99%

Section: Problem Formulationmentioning

confidence: 99%

See 1 more Smart Citation

A new noniterative method for pattern synthesis of unequally spaced linear arrays

Alijani

Neshati

2019

Int J RF Microw Comput Aided Eng

Self Cite

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“…In the array pattern optimization with some desired constraints such as low sidelobe level, narrow beam width, and controlled nulls, many of the design parameters could be saved by choosing their values non-adaptive [7][8][9][10]. Other techniques include the use of thinning process especially for the large planar arrays where the optimization processes are slow and difficult [11][12][13][14][15][16]. To overcome such problems, many researchers suggested using analytical methods rather than complex optimization based-iterative methods [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Rectangular Grid Antennas With Various Boundary Square-Rings Array

Mohammed¹

2021

PIER Letters

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Rectangular grid antennas are widely used in practice due to their advantages and versatility. This paper simplifies the design procedures of such antennas by optimizing their radiation characteristics using minimum number of the optimized elements while maintaining the same performance. The method consists of partitioning a fully square grid array into two unequally subplanar arrays. The first one contains the inner and the most central elements of the initial planar array in which they are chosen to be non-adaptive elements, while the remaining outer and boundary elements which constitute L number of the square-rings are chosen to be adaptive elements. Then, the optimization process is carried out on those outer rings instead of fully planar array elements. Compared to a standard N × M planar array with fully adaptive elements, the number of optimized elements could be reduced from N × M to 2{2L(N − L)}, so as to significantly reduce the system cost without affecting the overall array performance. Results of applying the proposed method to optimize a small 9 × 9, medium 20 × 20, and large 40 × 40 size planar arrays with various values of L are shown.

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“…Linear array antennas are grouped into two main categories including equal and unequal space between elements of the array [11,12]. Patterns synthesis techniques using Least Square Methods (LSM) has been developed for both categories, which avoids the computational problems associated with the direct calculation of a linear equations system and is used widely in a variety of engineering problems [13,14]. This technique formulates the problem for an ESLA a set of M equations with N unknowns, whereas M is the number of the sampled data of the desired pattern and N is the number of the array element.…”

Section: Introductionmentioning

confidence: 99%

Development a New Technique Based on Least Square Method to Synthesize the Pattern of Equally Space Linear Arrays

Alijani

Neshati

2019

IJE

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Using the sampled data of a desired pattern is a common technique in pattern synthesizing of array factor (AF) of antenna arrays. Based on the obtained data matrix, Least Square Method (LSM) is used to calculate the exciting coefficient of array elements. The most important parameter, which involves the accuracy and complexity of calculation, is the sampling rate of the desired pattern. Classical Least Square Method (CLSM) uses a linear combination of the samples, which provides low accuracy. In this paper, a new method is proposed by introducing a correction factor (CF) to increase the accuracy of the pattern estimation, while the design complexity is not increased basically. A normalized error between the desired and estimated pattern is considered and its variation versus CF is investigated. It is shown that for an optimum value of correction factor, CFopt, the defined error is minimum. The proposed method is examined for a few well-known arrays and the obtained results are reported and compared with those of classical LSM. It is shown that the introduced method accurately estimates the required pattern of array factors of equally spaced linear arrays (EALAs).

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Development a New Array Factor Synthesizing Technique by Pattern Integration and Least Square Method

Cited by 19 publications

References 10 publications

A new noniterative method for pattern synthesis of unequally spaced linear arrays

A new noniterative method for pattern synthesis of unequally spaced linear arrays

Rectangular Grid Antennas With Various Boundary Square-Rings Array

Development a New Technique Based on Least Square Method to Synthesize the Pattern of Equally Space Linear Arrays

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