Error analysis techniques for planar near-field measurements

Newell, Allen C.

doi:10.1109/8.1177

Cited by 260 publications

(149 citation statements)

References 6 publications

Supporting

Mentioning

128

Contrasting

Unclassified

Order By: Relevance

“…λ/2 sample spacing is commonly adopted along the length of the cylinder in the standard cylindrical and in the planar measurements due to FFT usage. Sample spacings coarser than λ/2 result in aliasing errors [5]. However, no such limitation applies to FIAFTA and the sample spacing is computed in relation with the number of unknowns required to solve the linear system of equations.…”

Section: Data Point Spacingmentioning

confidence: 99%

“…Therefore, the resulting error estimates predict an error which is unrealistically high. Newell performed more realistic error analyses in [5] making use of a known spatial dependency of the errors. This comprehensive analysis identifies the significant errors and also estimates the magnitude of all near-field error sources.…”

Section: Introductionmentioning

confidence: 99%

“…This comprehensive analysis identifies the significant errors and also estimates the magnitude of all near-field error sources. The presented 18-term error model in [5] is formally accepted by the National Institute of Standards (NIST) (formerly called National Bureau of Standards). Error equations are derived to determine the relationship between the measurement errors and the far-field results.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Near-Field Error Analysis for Arbitrary Scanning Grids Using Fast Irregular Antenna Field Transformation Algorithm

Qureshi¹,

Schmidt²,

Eibert³

2013

PIER B

View full text Add to dashboard Cite

Abstract-An extensive error analysis for arbitrary near-field antenna measurements is performed. Expressions are derived to estimate the far-field uncertainty using the available near-field data together with the measurement inaccuracy but, most importantly, without the knowledge of the reference far field. Error analysis techniques presented so far either assume a specific set of antennas or a specific measurement surface and are difficult to generalize. We present a generalized approach providing realistic error estimates using the recently developed Fast Irregular Antenna Field Transformation Algorithm (FIAFTA). FIAFTA utilizes equivalent plane wave sources to represent radiated antenna fields and is able to process nearfield data collected on arbitrary measurement grids. The unknown plane wave coefficients are determined by solving a linear system of equations. The error model is applied to planar, cylindrical, and spherical near-field measurements and is also valid for arbitrary measurement grids. The estimated far-field uncertainties show good agreement with the reference far-field errors.

show abstract

Section: Data Point Spacingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Near-Field Error Analysis for Arbitrary Scanning Grids Using Fast Irregular Antenna Field Transformation Algorithm

Qureshi¹,

Schmidt²,

Eibert³

2013

PIER B

View full text Add to dashboard Cite

show abstract

“…Special attention must be given to the probe pattern and positioning accuracy [1] as well as to the effects that error sources in NF acquisitions, such as truncation of the measurement plane, cable flexing, stray signals, leakage, etc., can introduce in the FF pattern of the AUT [1,2,13,14]. 1 The far-field distance is defined by R ¼ 2D 2 =λ (R >> λ), being D the maximum dimension of the antenna and λ the wavelength [1].…”

Section: Introductionmentioning

confidence: 99%

“…Nevertheless, phase acquisition, particularly at mm-and submm-wave bands, is a challenging task that requires sophisticated and expensive equipment due to the high thermal stability requirements and the effect of the errors, mostly resulting from thermal drift and cable flexing [1,[13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Indirect Off-Axis Holography for Antenna Metrology

Arboleya

Laviada

Ala‐Laurinaho³

et al. 2017

Holographic Materials and Optical Systems

View full text Add to dashboard Cite

Phase acquisition in antenna measurement, especially at millimeter-and submillimeterwave frequencies, is an expensive and challenging task. The need of a steady phase reference demands not only a very stable source but unvarying temperature conditions and strong positioning accuracy requirements. Indirect off-axis holography is an interferometric technique that allows for characterization of an unknown field by means of a simple filtering process of the hologram or intensity interference pattern in the spectral domain, provided that the reference field, employed to interfere with the unknown field, is known in amplitude and phase. This technique can be used to avoid the effect of the errors related to the phase acquisition and to further develop new efficient and robust techniques capable of phase retrieval from amplitude-only acquisitions allowing for cost and complexity reduction of the measurement setup. A short review of the state-of-theart in antenna metrology is presented in this chapter, as well as a description of conventional indirect off-axis techniques applied to this field. Last sections are devoted to the description of novel measurement techniques developed by the authors in order to overcome the main limitations of the conventional methods.

show abstract

Near‐Field Scanning Measurements: Theory and Practice

Francis

Wittmann

2007

Modern Antenna Handbook

View full text Add to dashboard Cite

As antennas increase in size or operating frequency, it becomes increasingly difficult to obtain adequate real estate to measure antenna properties in the far field. Typically, a distance of nD 2 /λ is specified as the beginning of the far-field region, where n is often 2 for routine work, D is the diameter of the smallest sphere that encloses the antenna's radiating parts, and λ is the wavelength. At this distance and for a spherical wavefront, the phase differs by π/8 between the center and edge of the antenna. For precision measurements, n often must be much greater than 2 [1, Chap. 14]. Table 19.1 shows the far-field distances for some sample antenna diameters and operating frequencies. We see that even for antennas of modest size, the far-field distance can become prohibitively large when the frequency is high enough. Thus there are situations where measuring an antenna in the near field would be advantageous because large amounts of real estate are not required. There are other advantages as well. Since the near-field method is usually employed inside a chamber, it is not subject to the effects of the weather and also provides a more secure environment.Determining the far-field pattern of an antenna from near-field measurements requires a mathematical transformation and correction for the characteristics of the measuring antenna (hereafter referred to as the probe).

show abstract

Error analysis techniques for planar near-field measurements

Cited by 260 publications

References 6 publications

Near-Field Error Analysis for Arbitrary Scanning Grids Using Fast Irregular Antenna Field Transformation Algorithm

Near-Field Error Analysis for Arbitrary Scanning Grids Using Fast Irregular Antenna Field Transformation Algorithm

Indirect Off-Axis Holography for Antenna Metrology

Near‐Field Scanning Measurements: Theory and Practice

Contact Info

Product

Resources

About