Beam deviations of large linear arrays due to wavy phase errors

Beam deviations occurring when wavy phase errors are introduced into the aperture of an antenna are treated. As the antenna becomes large, the probability of introduction of such types of phase error increases and beam deviations become a problem. A basic formula that permits the evaluation of beam deviations due to small phase errors is presented and applied to derive, in a general form, expressions for beam deviations which would occur when sinusoidal or rⁿ type phase error arises along a line source where r is a normalized distance and n is zero or a positive integer. Numerical examples show that sinusoidal phase errors often cause comparatively large beam deviations (relative to linear phase gradients), even for tapered illuminations