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d. d. θ. N Element Array. δ=kdsinθ. nδ. nδ/2. G. M. δ/2. δ. a. A. B. Phasor Addition. Directivity Index for an n-Element Array. Linear Array. Nulls:. q. D. Piston Array. Bessel Function. J 1 ( p Dsin q/l ). p Dsin q/l.
E N D
d d θ N Element Array
δ=kdsinθ nδ nδ/2 G M δ/2 δ a A B Phasor Addition
Linear Array Nulls:
q D Piston Array Bessel Function J1(pDsinq/l) pDsinq/l J1(pDsinq/l) has zero crossings (nulls) at pDsinq/l = 3.83, 7.02, 10.17, 13.32, 16.47, .... J1(pDsinq/l) has extremes (side lobes) at pDsinq/l = 1.84, 5.33, 8.54, 11.71, 14.86, ....