The Development of an EM-Field Probing System for Manual Near-Field Scanning

He, Hui; Maheshwari, Pratik; Pommerenke, David

doi:10.1109/temc.2015.2496376

Cited by 27 publications

(13 citation statements)

References 11 publications

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“…Therefore, the frequency band selection should be performed, considering the tradeoff between imaging resolution and penetration capabilities and the specific requirements of the practical applications of interest. Despite these powerful approaches for uniform data, last advances in electromagnetic imaging have shown that the use of portable scanners, driven by hand, can be useful for a large number of applications, including electromagnetic compatibility [15], people screening [16], or nondestructive evaluation [17]. However, these systems do not provide equally-spaced acquisition points.…”

Section: Green's Function-based Sar Imaging Methods Of Uniform Measurementioning

confidence: 99%

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Multi-Layered Circular Dielectric Structures’ Synthetic Aperture Radar Imaging Based on Green’s Function Using Non-Uniform Measurements

Álvarez-Narciandi

Laviada

2020

Remote Sensing

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The electromagnetic imaging of multi-layered circular structures can be accomplished by means of different approaches. Among these approaches, the use of synthetic aperture radar (SAR) techniques with the compensation of the Green’s function for multi-layered circular cylinders provides a trade-off between accuracy and computational complexity. Nevertheless, this approach relies on measurement points acquired uniformly. Thus, this prevents the adoption of more flexible sampling schemes, limiting the use of inaccurate positioners or manual scanners. To overcome this limitation, this paper proposes a method to handle non-uniform cylindrically acquired data, enabling multi-layered circular imaging based on non-uniformly acquired measurements. For this purpose, the presented method starts by projecting the non-uniformly measured points onto different circles with equally-spaced points. After that, the Green’s function-based circular-SAR imaging method is applied to each projection circle. Lastly, the final SAR image is obtained by the superposition of the images from the previous step. Numerical simulations and experimental results demonstrated the effectiveness and robustness of the proposed method for practical nondestructive testing (NDT) applications.

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Section: Green's Function-based Sar Imaging Methods Of Uniform Measurementioning

confidence: 99%

“…The position of the non-uniform measurement points can be recorded by means of affordable systems, such as depth-cameras [16] or motion capture systems [15,17]. Thus, the above problem becomes how to design the multi-layered C-SAR imaging algorithm once the non-uniform measurement points are known.…”

Section: Introductionmentioning

confidence: 99%

Multi-Layered Circular Dielectric Structures’ Synthetic Aperture Radar Imaging Based on Green’s Function Using Non-Uniform Measurements

Álvarez-Narciandi

Laviada

2020

Remote Sensing

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“…Research results in the field of the magnetic tracking are related to position and orientation estimates in magnetic tracking systems [14], development of magnetic tracking systems for near-field scanning [15], calibration of tracking systems for dynamic field distortion compensation [16], positional accuracy assessment and error modeling for magnetic tracking systems [17], etc. The measurement principle in magnetic tracking systems consists in calculation of the object spatial position.…”

Section: Measuring Logarithmic Signal Convertermentioning

confidence: 99%

Measuring Logarithmic Signal Converter for Magnetic Tracking Systems

Holyaka¹,

Marusenkova²,

Fedasyuk³

2020

MEM

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The work deals with the problem of signal conversion in magnetic tracking systems. Magnetic tracking systems are a novel development trend of navigation sensors within the concepts of the Internet of Things and virtual and augmented reality. In contrast to optical tracking systems, magnetic ones do not suffer from occlusions. In comparison with tracking systems built upon inertial sensors, they are not susceptible to bias drift and provide better accuracy. Magnetic tracking technology is based on calculating the position of objects upon the dynamic measurement of the reference magnetic field vectors. The reference magnetic fields are formed by arrays of actuator coils in the low-frequency electromagnetic radiation spectrum. Those who implement a magnetic tracking system have to ensure noise-immune measurements of signals coming from sensor coils in a wide dynamic measurement range. The range changes from microvolts for distances of several meters in couples "actuator-sensor" to hundreds of millivolts in the case if the distances in "actuator-sensor" couples reduce to several centimeters. Thus, one requires signal converters able to provide highly noise-immune measurements in a dynamic measurement range covering six orders of magnitude. The work presents the results of development, simulation, and investigation into a signal converter for magnetic tracking systems, whose novelty consists in combining the methods of logarithmic amplification and synchronous demodulation of the output signals of the sensor coils. The main nodes of the developed signal converter are a control unit, a logarithmic amplifier, a synchronous demodulator, a low-pass filter, an actuator driver and an analog-to-digital converter. Voltage logarithm compression has been performed upon volt-ampere characteristics of semiconductor p-n junctions. The synchronous demodulator provides a high level of selection of the useful signal out of electromagnetic noise. The results presented in this paper are part of our complex research work related to the development of the Magnetic Tracking System Integrated Development Environment (MTS-IDE). The latter is being developed by a team of scholars within different projects and is aimed at enhancing the efficacy of parametric optimization and synthesizing firmware of embedded systems implementing integrated magnetic tracking sensors. Simulation and experiments have shown that the dynamic range of noise-immune signal measurement using the developed converter covers six orders of magnitude, from 1E-6 V to 1 V. Investigation into functionality were conducted by oscillograph methods. The characteristics of the proposed solution were measured by the above-mentioned MTS-IDE. The obtained results are of key importance for further improvement of magnetic tracking systems, particularly, for their noise-immune measurement volume expansion.

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“…Near-field electromagnetic scanning methods are the main tools to locate EMI sources (e.g. [13], [14]). However, the presence of evanescent waves at close distances may cause faulty reconstruction of the source.…”

Section: Introductionmentioning

confidence: 99%

Localization of Electromagnetic Interference Sources Using a Time-Reversal Cavity

Karami

Azadifar

Mostajabi

et al. 2021

IEEE Trans. Ind. Electron.

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In this paper, we propose and implement a novel technique to locate Electromagnetic Interference (EMI) sources using the concept of time reversal cavity. We show in an intuitive manner that reflections from the surfaces of a cavity can emulate an infinite number of sensors in the Time Reversal (TR) method. In order to locate EMI sources, the equipment under test (EUT) is placed in a rectangular metallic cavity, of suitable dimensions according to the considered frequency band and the EUT size, equipped with a simple monopole or dipole antenna. We demonstrate that, by using only one sensor, we are able to locate EMI sources by taking advantage of the focusing properties of a time reversal cavity. The entropy criterion is applied to obtain the focusing time slice in which the maximum electric field determines the location of the EMI source. Both two-and three-dimensional numerical simulation schemes are deployed to demonstrate the ability of the proposed technique. The validity of numerical simulations is tested against frequency domain measurements. Compared to conventional EMI tests in anechoic chambers and scanning methods, the proposed technique represents a simpler and cost-effective test method requiring only one sensor (a monopole or dipole antenna).

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The Development of an EM-Field Probing System for Manual Near-Field Scanning

Cited by 27 publications

References 11 publications

Multi-Layered Circular Dielectric Structures’ Synthetic Aperture Radar Imaging Based on Green’s Function Using Non-Uniform Measurements

Multi-Layered Circular Dielectric Structures’ Synthetic Aperture Radar Imaging Based on Green’s Function Using Non-Uniform Measurements

Measuring Logarithmic Signal Converter for Magnetic Tracking Systems

Localization of Electromagnetic Interference Sources Using a Time-Reversal Cavity

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