Effect of random errors in planar near-field measurement

Abstract

A bstract-Expressions which relate the signal-to-noise ratio in the near field to the signal-to-noise ratio (WN) 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 to measure the noise in the far-field pattern is also given.

Synthesized-reference-wave holography for determining antenna radiation characteristics

“…Synthesized-reference-wave holography was proposed in a PhD thesis [21] where several aspects were thoroughly analyzed (these methods allow utilizing the advantages of methods for probe compensation of amplitude and phase near-field measurements for planar and cylindrical scanning [1][2][3][4][5][6][7][8][9][10][11][12], including accuracy analyses). Most of the results have been published [22][23][24][25][26][27][28], such as a description of holographic near-field measurements using probe compensation for planar and cylindrical scanning, a comparison of holographic near-field and far-field measurements with and without probe compensation, accuracy analyses using mathematical models considering random processes with correlation intervals, numerical simulations considering random errors as well as deterministic errors, and processing of measurement statistics.…”

Accuracy Analyses of Synthesized-Reference-Wave Holography for Determining Antenna Radiation Characteristics

“…The measurements (see below) indicated that the longitudinal z-position errors with u~~10-3 were the most important. The variances can be calculated using Equation (6). Assuming (see [8]) that ci = 2/N = 1/32 , the values shown in Figures 4 and 5 by dots were obtained.…”

“…If the individual errors are considered to be independent errors and ct ,c2 «1, then [8,19] aB(Kl,K2)0"1 The variances of the angular spectra are given by Equation (6). The individual terms, a B(j~and aq(j~, are given by Equations (7) and (8).…”

“…Near-field measurements using synthesized-reference-wave holography with probe compensation for planar and cylindrical scanning allow employing the advantages of methods for probe compensation for the amplitude and phase of near-field measurements for planar -and cylindncal scanning, including accuracy analyses [1][2][3][4][5][6][7], which should be slightly modified. However~accu-racy analyses using mathematical models considering random processes with correlation intervals, measurements using statistical processing, and numerical simulations considering random as well as deterministic errors have been done, and they are described below.…”

“…(These methods allow employing the advantages' of methods for probe compensation for amplitude and phase near-field measurements for planar and cylindrical scanning, including accuracy analyses [1][2][3][4][5][6][7]). Most of the results have been published [10][11][12][13][14][15][16], such as a description of holographic near-field measurements using probe compensation for planar and cylindrical scanning; a comparison of holographic near-field and far-field measurements with and without probe compensation; accuracy analyses using mathematical models considering random processes with correlation intervals; numerical simulations considering random errors as well as deterministic errors; and the processing of measurement statistics.…”