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Tapering of Arrays

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Tapering of Arrays. Objective is to reduce the side lobes , which not only the amount of power is wasted in the directions of minor lobes but unnecessary interferences are also caused in those area. - PowerPoint PPT Presentation

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Tapering of ArraysObjective is to reduce the side lobes, which not only the amount of power is wasted in the directions of minor lobes but unnecessary interferences are also caused in those area.

Side lobes often termed as Side lobe ratio which is the ratio of power density of the main lobes to the power density of longest minor lobes and it is expressed in dB, it is called as Side-lobe-level.

The techniques used in Tapering is current or amplitudes in the sources of a linear array is non-uniform.

It is found that minor lobes are reduced if the center source radiates more strongly than the end sources and hence this tampering is done from center to end.

The tapering follows coefficients of binomial series and Tchebysceff polynomial Binomial ArraysEquation-1 Pascals Triangle

HPBW increases and hence the directivity decreases.For design of a large array, larger amplitude ratio of sources is required.Disadvantage of Binomial ArraysTchebyshev polynomialTm(x)=cos(m cos-1 x), -1

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