An improved method of reducing SWE order for phaseless spherical near-field antenna measurement

Wang, Weimin; Han, Ya; Gao, Huaqiang; Wu, Yongle; Lai, Zhengrong; Liu, Yuanan

doi:10.1016/j.aeue.2020.153199

Cited by 5 publications

(3 citation statements)

References 19 publications

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“…In total, the linear system in (1) has become a quadratic, thus, nonlinear system of equations depending on (𝑛 P + 𝑛 A ) unknowns. Interestingly, the problem of phaseless NFFFTs [44]- [50], [52]- [54], [57], [68], [69] can also be cast in the form of (2). In fact, the problem in (2) can be considered a generalization and, thus, more demanding version of the phase retrieval problem [70]- [74].…”

Section: B Transformation With Unknown Probesmentioning

confidence: 99%

Fully Probe-Corrected Near-Field Far-Field Transformations with Unknown Probe Antennas

Paulus¹,

Eibert²

2023

Preprint

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<p>According to the electromagnetic uniqueness theorem, the radiation behavior of an antenna under test (AUT) can be recovered from measurements of two tangential components of its radiated fields on an enclosing surface. In practice, measurements conducted in the radiating near-field (NF) of an AUT utilize probe antennas of finite size. Thus, instead of discrete field values, spatially blurred probe signals are acquired. The probe influence can be compensated, however, this commonly requires precise knowledge about the probe antenna. In this work, the concept of NF far-field (FF) transformations (NFFFTs) with full correction of the influence of unknown probe antennas is introduced. Two nonconvex and two convex formulations are presented and their relation to the similar task of phase retrieval is highlighted. Simulation and measurement results illustrate the validity of the concept, shed light on the required complexity of measurement setups, and illustrate limitations of the approach. Special attention is paid to the case of high practical relevance when AUT and probe are identical.</p>

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Section: B Transformation With Unknown Probesmentioning

confidence: 99%

Fully Probe-Corrected Near-Field Far-Field Transformations with Unknown Probe Antennas

Paulus¹,

Eibert²

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…In particular, non-redundant sets of unknowns are advisable for nonlinear problems, as they can both improve the convergence speed of nonlinear solvers and reduce the occurrence of suboptimal solutions. Interestingly, the problem of phaseless NFFFTs [44]- [50], [52]- [54], [57], [68], [69] can also be cast in the form of (2). In fact, the problem in (2) can be considered a generalization and, thus, more demanding version of the phase retrieval problem [70]- [74].…”

Section: B Transformation With Unknown Probesmentioning

confidence: 99%

Fully Probe-Corrected Near-Field Far-Field Transformations With Unknown Probe Antennas

Paulus

Eibert

2023

IEEE Trans. Antennas Propagat.

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According to the electromagnetic uniqueness theorem, the radiation behavior of an antenna under test (AUT) can be recovered from measurements of two tangential components of its radiated fields on an enclosing surface. In practice, measurements conducted in the radiating near-field (NF) of an AUT utilize probe antennas of finite size. Thus, instead of discrete field values, spatially blurred probe signals are acquired. The probe influence can be compensated, however, this commonly requires precise knowledge about the probe antenna. In this work, the concept of NF far-field (FF) transformations (NFFFTs) with full correction of the influence of unknown probe antennas is introduced. Two nonconvex and two convex formulations are presented and their relation to the similar task of phase retrieval is highlighted. Simulation and measurement results illustrate the validity of the concept, shed light on the required complexity of measurement setups, and illustrate limitations of the approach. Special attention is paid to the case of high practical relevance when AUT and probe are identical.

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“…The scanning of the reflector can be realized by moving the frame along x, y and z directions, to obtain the near-field intensity (or phase) distributions of antennas, typically, on a near-field planar grid. The SNR of this method is usually high enough and the near-field intensity and phase of signals can be obtained simultaneously by a vector network analyzer (VNA), while with the aperture of the antenna becomes larger, the scanning area increases exponentially, which results in the doubling of working time (Ghaffar et al 2008;Wang et al 2020;Morris 2007). At the same time, the scanning is hard to implement on a heavy aperture reflector due to the huge equipment used by this method.…”

Section: Introductionmentioning

confidence: 99%

Deformation measurement by single spherical near-field intensity measurement for large reflector antenna

Wang

Yao

et al. 2021

Res. Astron. Astrophys.

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This paper presents a new method to obtain the deformation distribution on the main reflector of an antenna only by measuring the electric intensity on a spherical surface with the focal point as the center of the sphere, regardless of phase. Combining the differential geometry theory with geometric optics method, this paper has derived a deformation-intensity equation to relate the surface deformation to the intensity distribution of a spherical near-field directly. Based on the finite difference method (FDM) and Gauss-Seidel iteration, deformation has been calculated from intensity simulated by geometrical optics (GO) and physical optics (PO) methods, respectively, with relatively small errors, which prove the effectiveness of the equation proposed in this paper. By means of this method, it is possible to measure the deformation only by scanning the electric intensity of a single hemispherical near-field whose area is only about 1/15 of the aperture. The measurement only needs a plane wave at any frequency as the incident wave, which means that both the signals from the outer space satellite and the far-field artificial beacon could be used as the sources. The scanning can be realized no matter what attitude and elevation angle the antenna is in because the size and angle of the hemisphere are changeable.

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An improved method of reducing SWE order for phaseless spherical near-field antenna measurement

Cited by 5 publications

References 19 publications

Fully Probe-Corrected Near-Field Far-Field Transformations with Unknown Probe Antennas

Fully Probe-Corrected Near-Field Far-Field Transformations with Unknown Probe Antennas

Fully Probe-Corrected Near-Field Far-Field Transformations With Unknown Probe Antennas

Deformation measurement by single spherical near-field intensity measurement for large reflector antenna

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