ABSTRACT
Random amplitude and phase errors cause increased side lobe levels, pointing errors and reduced directivity [8]. Random phase and amplitude errors can be treated statistically. The phase error φn is described by a Gaussian probability distribution with zero mean and variance φ¯2n . The amplitude error δn has variance δ¯2n and zero mean. The average side lobe level due to random phase and amplitude errors can be expressed as
σ¯ 2I = [ φ¯2 + σ¯ 2
] × ge , (10.10)
where
σ 2I = the average side lobe level relative to the isotropic side lobe level in the plane of the linear array axis
ge = the element directivity. The reduction of directivity for a linear array due to random phase and amplitude errors is given by
D
D0 = 1
1 + φ¯2 + σ 2 , (10.11)
where
D = the directivity of the array with errors D0 = the directivity of the error free array.
