Comparison of Linear and Planar Array antennas for Target Detection Improvement Using Hyper Beam Technique

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1 Comparison of Linear and Planar Array antennas for Target Detection Improvement Using Hyper Beam Technique 1 I.Sreedevi, 2 S. Sri Jaya Lakshmi, 3 T.V. Rama Krishna, 4 P.Ramakrishna, 5 M.Aditya, 6 N. Ravi Teja, 7 E. Nymisha Reddy 1,2,3,4,5,6,7 Dept. of ECE, KL University, Vaddeswaram, Guntur, AP, India Abstract In this paper, we proposed hyper technique to reduce the side and half, also reduce the grating s. The main objective of this paper is to generate the pattern for linear and planar arrays with changing the number of elements and exponent value p. Here we compare the patterns for linear and planar array for different exponent values and number of elements. The results shows that planar array yields much reduction of side s, half and grating s compared to linear array. allow steering in that particular direction without steering, i.e. all elements have the same phase or all elements are connected in parallel, in short forming is done by summing up all the transducer elements which yield a main. Keywords Hyper, Linear Array Antenna, Planar Array Antenna, Lobe Level, Beams Width, Grating Lobe I. Introduction In [1], they proposed Simple Matrix Inversion (SMI) algorithm, control of peak, side s. In this the weights are adjusted so as to minimize the output noise. Which results the much distortion in mail, would degrade tracking performance, and high side s would results in raise of grating s. In reference [2], they used an adaptive algorithm based on the conventional RLS algorithm, is derived to update the weight sub vectors. Here the original array is splits into several adaptive sub arrays. Increase the convergence of adaptive arrays, will increase the converge speed. In [3], they proposed calibration technique for arrays, which yields bearing estimation. This technique is mainly applied on music estimators with two or more signals exit in the single field so as to estimate the true gain and phase. In our paper we proposed hyper technique, which yields reduction of side s, grating s and also noise reduction in target detection. II. Methodology For every high performance system having noise reduction and improvement of detection of the target is necessary. To achieve this new technical approach such as forming algorithms are to be used during the design of the array antennas. For this we use the hyper forming technique, which offers reduction, side suppression and grating s. A. Hyper Beam The hyper formation by means of two half s with hyper equation given below. The two-dimensional Hyper focusing in one plane which contains the main direction is further studied, in order to achieve even greater reduction of and the side s around the main in all directions for both the linear and planar transducer. B. Generation of Hyper Beam The fig. 1 and 2, show simple linear and planar arrays respectively on which the hyper technique is to be applied for the generation of main. The element spacing in one direction is half a wave length ( l / 2 ) in order to reduce the grating s and 122 International Journal of Electronics & Communication Technology Fig. 1: Simple Linear Transducer for Hyper Beam Generation Fig. 2: Simple Planar Transducer for Hyper Beam Generation C. Forming of a Hyper Beam The formation of the hyper sum and difference pattern for linear array is shown in fig. 3, fig. 5, for planar array is shown in fig. 4 and fig. 6. Fig. 3: 2D Sum Patterns of 10 Linear Array

2 IJECT Vo l. 3, Is s u e 2, Ap r i l - Ju n e 2012 and not on the magnitude s. III. Mathematical Formulas The equations for the creation of sum, difference and simple hyper are as follows: The array factor equation for simple linear array is N AF (θ) = I n e j(n-1)kd [sinθcosϕ+α n ] n=1 α n = -sinθ 0 cosϕ 0, n=1, 2,.,N The sum pattern is calculated from two half s is given by Fig. 4: 2D Sum Pattern of 10x10 Planar Array The sum is created by complex summation of the left and right half s. The magnitude, which is plotted in the patterns, is identical for the left and right half s similarly it is also identical to the sum of the magnitudes of both half s because of the normalized plots. The of sum pattern for linear array is 28 degrees, for planar array is 18 degrees. Difference is created by the difference of the right half signal subtracted from the left half signal by considering the phases of the signals. It is obvious that the values of the difference at each given direction are always lower or equal to those of the half. Furthermore the difference has a minimum in the direction of the sum at 00 as shown in fig. 5 and fig. 6. Fig. 5: 2D Difference Patterns of 10 Linear Array S (θ) = R L + RR The difference pattern is calculated from below equation D (θ) = RL RR The array factor equation for simple planar array is AF ( ) = Where, The sum pattern is calculated from two half s is given by S ( ) = R L + RR The difference pattern is calculated from below equation D ( ) = RL RR Then the equation to obtain simple Hyper for both linear and planar array is H hyp = R L + R R - R L - R R The equation of the general hyper is a function of the hyper exponent p: H hyp = {( R L + R R ) p ( R L - R R ) p } 1/p For linear array where, N/2 R L = e j(n-1)kd(sinθcos -sinθ cos ) 0 0 n=1 N R R = e j(n-1)kd(sinθcos -sinθ sin ) 0 0 n=n/2 Where, k=2π/λ, p=exponent value. For planar array where Where, Fig. 6: 2D Difference Pattern of 10x10 Planar Array Based on the interrelation between the sum pattern and the difference pattern observed on comparison of the two we can come to the idea of subtracting the magnitude of the difference pattern from the sum half pattern. The subtraction operation has to be performed rather on the magnitude numbers themselves, And p ranges from 0.1 to 1. IV. Results A. Radiation Patterns Using the Hyper effect, side s can be amplified and controlled. By varying the exponent value u, different hyper patterns are obtained for both linear and planar arrays. By comparing results the side of planar array is less. For u=1, u=0.5 and u=0.1 and N=10, N=15 we plot the results as follows: In t e r n a t i o n a l Jo u r n a l o f El e c t r o n i c s & Co m m u n i c a t i o n Te c h n o l o g y 123

3 Fig. 7: Hyper Beam Pattern of 10 Linear Array with Exponent Fig. 11: Hyper Beam Pattern of 10 Linear Array with Exponent Fig. 8: Hyper Beam Pattern of 10x10 Planar Array with Exponent Fig. 12: Hyper Beam Pattern of 10x10 Planar Array with Exponent Fig. 9: Hyper Beam Pattern of 10 Linear Array with Exponent Fig. 13: Hyper Beam Pattern of 15 Linear Array with Exponent Fig. 10: Hyper Beam Pattern of 10x10 Planar Array with Exponent Fig. 14: Hyper Beam Pattern of 15x15 Planar Array with Exponent 124 International Journal of Electronics & Communication Technology

4 IJECT Vo l. 3, Is s u e 2, Ap r i l - Ju n e 2012 linear array 9degrees and -23dB, for 15x15 planar array 8degrees and -45dB respectively. For p=0.5, the half and side for 10 element linear array are 10 degrees and -28dB, and for 10x10 planar array 8 degrees and -50dB, for 15 element linear array linear array 7.2 degrees and 40dB, for 15x15 planar array 6.8degrees and -45dB respectively. For p=0.1, the half and side for 10 element linear array are 1.2 degrees and -125dB, and for 10x10 planar array 0.6 degrees and -140dB, for 15 element linear array linear array 0.25degrees and -160dB, for 15x15 planar array 0.2degrees and -200dB respectively. Fig. 15: Hyper Beam Pattern of 15 Linear Array with Exponent B. Tabular Forms The side s are tabulated in tabular form: For N=10 elements Linear array Planar array Exponent Value (p) 1-16dB 14o -35dB 12o dB 10o -50dB 8o dB 1.2o -140dB 0.4o Fig. 16: Hyper Beam Pattern of 15x15 Planar Array with Exponent For N=15 elements Linear array Exponent Value (p) 1-23dB 9o Planar array -45dB 8o dB 7.2o -60dB 6.8o dB 0.25o -200dB 0.2o Fig. 17: Hyper Beam Pattern of 15 Linear Array with Exponent V. Conclusion As we conclude that by comparing the results for various values of exponent value and number of elements, planar array has less side over the linear array. The results shown that planar array has reduction of side s and grating s is proved with the proposed method. Fig. 18: Hyper Beam Pattern of 15x15 Planar Array with Exponent For p=1, the half and side for 10 element linear array are 14 degrees and -16dB, and for 10x10 planar array 12 degrees and -35dB, for 15 element linear array VI. Acknowledgment The authors would like to thank the management of KL University, Vijayawada for excellent encouragement during the tenure of work. References [1] Renbiao Wu, Zheng Bao, Yuanliang Ma.,"Control of Peak Level in Adaptive Arrays. [2] Shiann-Jeng Yu, Ju-Hong Lee,"Adaptive Array Beamforming Based on an Efficient Technique. [3] B.P. Ng, M.H. Er, C. Kot,"Array gainlphase calibration techniques for Adaptive forming and direction finding. [4] TITUS Lo, JOHN LITVA, Adaptive Beam-Space Nulling of Multipath Signals. In t e r n a t i o n a l Jo u r n a l o f El e c t r o n i c s & Co m m u n i c a t i o n Te c h n o l o g y 125

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