Effect of random errors in planar near-field measurement

Expressions that relate the signal-to-noise ratio in the near field to the signal-to-noise ratio in the far field are developed. The expressions are then used to predict errors in far-field patterns obtained from near-field data. A technique for measuring the noise in the calculated far-field pattern by calculating the spectrum in the evanescent region from a single-dimensional oversampled scan is also described.>