The design, fabrication, and characterization of an ultrawideband (UWB) antenna for near-field microwave imaging dielectric objects are presented together with the setup. focus is on application in breast tumor detection. new operates as a sensor following properties: 1) direct contact imaged body; 2) more than 90% power coupled directly into tissue; 3) UWB performance; 4) excellent de-coupling from outside environment; 5) small size; 6) simple fabrication. includes return loss, total...

In this paper, we propose a new procedure to estimate the shape of opening and depth profile an arbitrary three-dimensional (3-D) defect from magnetic flux leakage (MFL) measurements. We first use Canny edge detection algorithm opening. Then inversion based on space mapping (SM) methodology in order approximate efficiently. To demonstrate accuracy proposed technique, reconstruct defects shapes simulated MFL signals. The is then tested with experimental data two metal-loss defects. both...

A new 3-D holographic microwave imaging technique is proposed to reconstruct targets in the near-field range. It based on Fourier analysis of wideband transmission and reflection signals recorded by two antennas scanning together along rectangular parallel apertures both sides inspected region. The complex scattering parameters are collected at several frequencies then processed obtain a representation target terms 2-D slice images all desired range locations. No assumptions made about...

This survey overviews recent advancements in wireless soil sensing technologies, such as sensors and communication systems to manage enhance health crop production for sustainable agricultural practices. The surveyed technologies are categorized by the target parameters, moisture, temperature, salinity, pH, nutrient concentration, pressure, heavy metals content. Special focus is placed on passive semi-passive principles data collection, transmitting sensed data, machine learning approaches...

A novel TEM horn antenna placed in a solid dielectric medium is proposed for microwave imaging of the breast. The major design requirement that couples energy into tissue without being immersed itself coupling medium. achieves this by: 1) directing all radiated power through its front aperture, and 2) blocking external electromagnetic interference by carefully designed enclosure consisting copper sheets absorbing sheets. In whole ultra-wide band features: good impedance match, uniform field...

Microwave holography requires knowledge of the incident field and Green tensor background medium. In near-field imaging, analytical models these are inadequate use electromagnetic simulations has been previously proposed. practice, however, fidelity such may also be insufficient. Here, we propose a measurement method for acquisition this information, thus eliminating need to estimate it analytically or numerically. We validate approach through simulated data acquisitions as well experiments....

Detection of pollutants in water is conventionally performed wet chemistry labs for samples that are collected manually. This task time-consuming, costly, and difficult to expand large bodies perform frequently. Thus, facilitate quality testing, a new methodology presented based on the use non-uniform array microwave sensors applying machine learning data. The sensor elements resonate at different frequencies which cover broad bandwidth, providing sufficient information algorithms determine...

We present an inversion methodology for defect characterization using the data from magnetic flux leakage (MFL) measurements. use a single tangential component of field as MFL response. The procedure employs space mapping methodology. Space is efficient technique that shifts optimization burden computationally expensive accurate (fine) model to less (coarse) but fast model. Here fine finite-element method (FEM) simulation, while coarse based on analytical formulas. achieve good estimation...

A new two-dimensional (2D) holographic microwave imaging technique is proposed to reconstruct the 2D image of a target. It based on Fourier analysis data recorded by two antennas scanning together separate rectangular parallel apertures both sides The complex back-scattered signals are first processed localize target in range direction. Then, reconstructed. No assumptions made about incident fields, which can be derived either simulation or measurement. Both and forward-scattered used This...

Fine-grained water quality data can facilitate the optimized management of resources, which have become increasingly scarce due to population growth, increased demand for safe sources water, and environmental pollutions. There is a pressing need cost-effective, reliable, re-usable, autonomous sensing technologies that provide accurate real-time measurements. In this paper, we present microwave sensor array with elements operating at different frequencies in wide frequency band 1 GHz 10 GHz....

Conventional nondestructive testing techniques do not suffice to efficiently inspect the defects in multiple nonmetallic pipes. Thus, this article, we propose a novel method for inspection of these components based on near-field microwave holographic imaging augmented with beamspace transformation. This approach harnesses ability microwaves 3-D by measuring backscattered fields region. In proposed technique, augment solution through use transformation which allows focusing each pipe during...

We propose a procedure for full characterization of rectangular surface-breaking cracks based on measurements only one tangential component the magnetic field with flux leakage (MFL) technique. The parameters interest include orientation, length, and depth cracks. assume that length investigated are much larger than crack width, so variation MFL response respect to width is negligible. Our employs fast direct methods provide reliable estimation in three separate consecutive steps. denoising...

This paper reports the progress toward a fast and reliable microwave imaging setup for tissue exploiting near-field holographic reconstruction. The consists of two wideband TEM horn antennas aligned along each other's boresight performing rectangular aperture raster scan. sensing is performed without coupling liquids. At scanning position, data acquired. Then, novel algorithms are implemented to provide three-dimensional images inspected domain. In these new algorithms, required incident...

Gesture recognition, in particular, hand gesture has received great attention the field of human–computer interaction (HCI). Although several recognition designs have been proposed past, they still suffer many limitations practice. Hence, we present a wearable device, called GloveSense, which is made on regular glove using conductive threads. The system consists ten coils, with each pair coils sewn both sides finger and connected series. To achieve high sensitivity, data acquisition...

In this paper, we propose an approach to overcome the well-known "diffraction limit" when imaging sources several wavelengths away. We employ superdirectivity antenna concepts design a well-controlled superoscillatory filter (SOF) based on properties of Tschebyscheff polynomials. The SOF is applied reconstructed images from holographic algorithms which are back-propagation principle. demonstrate capability point-sources away in one-, two-, and three-dimensional with super-resolution. also...

Abstract An electromagnetic corrosion inspection tool was designed to accurately assess in as many five nested pipes. This paper provides details of the principles operations and methodology algorithms used for data processing this tool. uses eddy current principle includes two transmitters eight receivers. It operates continuous wave mode at multiple frequencies. Optimized transmitter-receiver spacing configurations multifrequency operation provide sufficiently diverse information help...

Holographic microwave imaging is fast and robust it has been adapted for near-field applications such as biomedical nondestructive testing. While the technique fast, synthesizing a 2-D aperture by mechanical scanning of antennas takes time. Here, antenna arrays are used to expedite data acquisition along azimuthal direction in cylindrical holographic setup. To deal with limited nonuniform samples direction, three approaches evaluated, which, we use interpolation, uniform or discrete Fourier...

In the alternative current field measurement (ACFM) technique, nonzero value of liftoff distance for magnetic sensor acts as a low-pass filter on surface crack signals, causing errors in detection and sizing. We present blind deconvolution algorithm evaluation signal restoration. The employs available closed-form expressions distribution electromagnetic fields at metal vicinity crack. To examine accuracy algorithm, we use original restored signals sizing by wavelet network inversion method....

This study presents an approach to estimate the characteristics of multiple narrow-opening cracks from magnetic flux leakage (MFL) signals. The number, locations, orientations and lengths are objective inversion process. proposed procedure provides a reliable estimation crack parameters in two separate consecutive steps. In first step, Canny edge detection algorithm is used cracks. Then, based on space mapping order depths efficiently. accuracy examined via simulations finite element method...

A full vector three-dimensional holographic technique is proposed for near-field imaging of dielectric bodies. This new formulation allows the processing two (co- and cross-polarized) scattered field components in a single reconstruction process. We demonstrate that employing both co- cross-polarized signals leads to significant improvement target shape reconstruction. The simulated examples X-shaped square-shaped targets lossy background medium are presented.

We propose a three-dimensional microwave holographic imaging method based on the forward-scattered waves only. In proposed method, one transmitter and multiple receivers perform together two-dimensional scan two planar apertures opposite sides of inspected domain. The ability to achieve without back-scattered enables high-loss objects, for example, tissues, where may not be available due low signal-to-noise ratio or nonreciprocal measurement setup. simulation experimental results demonstrate...

In this paper, a novel methodology is proposed for material identification. It based on the use of microwave sensor array with elements resonating at various frequencies within wide range and applying machine learning algorithms collected data. Unlike previous sensing systems which are mainly single sensor, allows characterization over frequency which, in turn, improves accuracy identification procedure. The performance tested via easily available materials such as woods, cardboards,...

Recently, nonmetallic materials, which are resilient to corrosion, low cost, and lightweight, have been exploited in many industrial sectors such as oil gas field. A common application of them is the form pipes. Despite advantages, these pipes can be damaged by delamination, defects, holes, erosion, may lead major production failures or even environmental catastrophes. To prevent issues, nondestructive testing (NDT) required replace components a timely manner. Due fact that traditional NDT...