The interest of this paper centers on fabrication and characterization and modeling of vortices i... more The interest of this paper centers on fabrication and characterization and modeling of vortices in high temperature superconducting thin films. As a first step, the magnetic vertices of the superconducting matrix were modeled. As a second, Bi-Sr-Ca-Cu-O thin films were grown using Pulsed Laser Ablation (PLD) on single crystal MgO substrates as magnetic templates for the potential use for Nano
This paper shows that DNG metamaterials enhance the sensitivity and range of the evanescent field... more This paper shows that DNG metamaterials enhance the sensitivity and range of the evanescent field probes. A conventional evanescent field probe produces all polarizations of the E and H fields. Therefore the experimental verification of the theory is not easy since a low loss, three dimensional DNG metamaterial is required. In this paper we propose a structure that can be used for verification of the sensitivity enhancement using a two dimensional DNG metamaterial. Theoretical results and numerical validation using the finite element method are presented.
In this paper, electromagnetic coupling between closely-spaced high-profile antennas is investiga... more In this paper, electromagnetic coupling between closely-spaced high-profile antennas is investigated with particular focus on multiple-input multiple-output (MIMO) systems. Monopole, and axial model helical antennas are considered in this study. Single- negative (SNG) metamaterials insulator were designed and placed between the antenna elements. Numerical and Experimental results show that better impedance matching can be achieved when using the magnetic resonators, as compared to the air case. Moreover, an almost 20 dB reduction in mutual coupling between antenna elements has been achieved.
In this paper, a new method based on strip line structures is presented for characterization of m... more In this paper, a new method based on strip line structures is presented for characterization of metamaterials. The proposed method is suitable for characterization of all types of artificial structures including Single Negative (SNG) and Double Negative (DNG) media. The new method has the advantages of easy fabrication and low cost, when compared to free space or the waveguide methods. Furthermore, it has the advantage of extracting both permittivity, e, and permeability, μ, with a single measurement, when compared to microstrip line method.
In this paper, we define a sensitivity measure for evanescent field detectors and show that a dis... more In this paper, we define a sensitivity measure for evanescent field detectors and show that a dispersive and lossless DNG slab increases the sensitivity. Since evanescent field based measurement modalities have limited range of detection, we analyze the effect of the DNG lens on the range of the evanescent field detections. By increasing their range, evanescent field probes can be used for noninvasive detection of material properties with an increased sensitivity for deeper regions.
In this paper, artificial magnetic resonators are used in order to reduce mutual coupling in Mult... more In this paper, artificial magnetic resonators are used in order to reduce mutual coupling in Multiple-input Multiple-Output (MIMO) systems. Split-ring resonator (SRR) inclusions are inserted between closely-spaced high-profile monopole antenna elements. It is shown that mutual coupling between the antenna elements can be reduced significantly by incorporating such magnetic inclusions. The magnetic materials work as insulators, and thus can be applied in a variety of antenna applications.
Near-field probes are attractive because they provide sub-wavelength resolution. Typical detectio... more Near-field probes are attractive because they provide sub-wavelength resolution. Typical detection using near field probes involves defects or irregularities present on the surface of the material. Sub-surface defects or irregularities are much more difficult to detect due to the fast decay of evanescent waves emanating from the probe. This work present novel probes employing metamaterial particles which work to substantially enhance the evanescent field energy in the vicinity of the probe, thereby increasing the sensitivity of the probe and enabling subsurface detection. Two experiments are presented where conducting metallic objects immersed in saline water and sand are detected. The results and findings presented here are expected to have strong implications in a wide range of sub surface detection challenges including detection of biological anomalies in human tissue, land mine detection, through-wall detection amongst other applications.
Recently, it was shown that single negative media can significantly enhance the sensitivity of ne... more Recently, it was shown that single negative media can significantly enhance the sensitivity of near-field probes. Inspired by this recent finding, a new near-field probe is proposed for noninvasive subsurface detection. The new probe uses a single split ring resonator (SRR) instead of a periodic arrangement of SRRs for negative material realization. Experimental tests were conducted to detect the presence of cracks on aluminum plates, the presence of small aluminum blocks located behind a layer of ground chicken (lossy medium), and the presence of a small aluminum block submerged in sodium chloride solution (lossy medium) with a salinity of 1%. Preliminary results show that the proposed near-field probe enables detection of electrically small targets buried in lossy media.
IEEE Transactions on Microwave Theory and Techniques, 2011
Most of the previous microwave near-field probes and imaging techniques focused on surface imagin... more Most of the previous microwave near-field probes and imaging techniques focused on surface imaging, providing ultra- high lateral resolution. Few microwave near-field probes were de- veloped for subsurface detection, offering both high lateral and depthresolutionwithvaryingdegreesofeffectiveness.Inthiswork, a novel microwave near-field probe using a single split-ring res- onator is introduced with the primary focus of subsurface detec- tion. The design is simple,
Recently, we showed that single negative media can significantly enhance the sensitivity of near-... more Recently, we showed that single negative media can significantly enhance the sensitivity of near-field probes. Inspired by this recent finding, we propose a new near-field probe that uses only one single split ring resonator instead of a periodic arrangement of these resonators. We show through numerical simulations that the new proposed probe lead to significant enhancement in the sensitivity as measured by the change in phase in the reflection coefficient. Experimental tests were conducted to detect the presence of a small aluminum block located behind a layer of ground chicken (lossy medium). Preliminary results show that with our new probe, a phase change in the reflection coefficient of 14 degrees can be achieved for 2 mm thick ground chicken and 6.24 mm aluminum cube at an operation frequency of 1.16 GHz.
The characteristic impedance and propagation constant formulation of conventional microstrip line... more The characteristic impedance and propagation constant formulation of conventional microstrip lines are analyzed for substrates made of negative materials. It is shown that the formulation can be used for negative material characterization when w/h is larger than 3. For narrow strips, the formulation is valid for low permittivity values. The method is a low cost and wide band characterization technique for negative material characterization.
Recently, it was shown that single negative media can significantly enhance the sensitivity of ne... more Recently, it was shown that single negative media can significantly enhance the sensitivity of near-field probes. Inspired by this recent finding, a new near-field probe is proposed for noninvasive subsurface detection. The new probe uses a single split ring resonator (SRR) instead of a periodic arrangement of SRRs for negative material realization. Experimental tests were conducted to detect the presence of cracks on aluminum plates, the presence of small aluminum blocks located behind a layer of ground chicken (lossy medium), and the presence of a small aluminum block submerged in sodium chloride solution (lossy medium) with a salinity of 1%. Preliminary results show that the proposed near-field probe enables detection of electrically small targets buried in lossy media.
IEEE Transactions on Antennas and Propagation, 2011
This work presents analysis of the behavior of open-ended coaxial near-field probes in the presen... more This work presents analysis of the behavior of open-ended coaxial near-field probes in the presence of -negative material. The effect of using negative material layers on the sensitivity is studied. It is shown that optimal conditions related to the thickness and constitutive parame- ters of the negative medium give rise to significant enhancement in probe sensitivity which allows the probe
In this work, we present the first experimental verification of the sensitivity improvement of ev... more In this work, we present the first experimental verification of the sensitivity improvement of evanescent field probes using single negative (SNG) metamaterials. The response of an electrically small probe to an electrically small target is investigated. The deviation in the phase of reflection coefficient due to the target is measured. When an SNG layer is employed, phase shift due to
In this work, a new EMP design is provided. By inserting an electrically small planar resonator a... more In this work, a new EMP design is provided. By inserting an electrically small planar resonator a unit cell of single negative media to a simple rectangular loop, the evanescent field in the near-field region is enhanced. As a result the sensitivity of the probe is improved significantly compared to a probe without SRR. The experiments in different media indicate
IEEE Transactions on Microwave Theory and Techniques, 2011
Most of the previous microwave near-field probes and imaging techniques focused on surface imagin... more Most of the previous microwave near-field probes and imaging techniques focused on surface imaging, providing ultrahigh lateral resolution. Few microwave near-field probes were developed for subsurface detection, offering both high lateral and depth resolution with varying degrees of effectiveness. In this work, a novel microwave near-field probe using a single split-ring resonator is introduced with the primary focus of subsurface detection. The design is simple, compact, inexpensive, and easy to fabricate using printed circuit board technology. Fourier spatial analysis of the field of the new probe reveals a substantial enhancement of the evanescent field, thus making a significant difference in subsurface detection. Experimental results illustrate that a small 3.24-mm aluminum block immersed in 1% sodium chloride (NaCl) solution and positioned 4 mm away from the surface was successfully detected using a probe operating at 1.218 GHz. For this particular experiment, where the size of the object was λ/74 , the detection ability of the new probe was tested using 2% and 3% NaCl solution as well. The phase changes due to the depth of the object demonstrate that the new probe is able to sense the presence of the same object in very lossy medium (3% NaCl whose loss tangent is approximately unity) with depth of 1-2 mm in spite of a standoff distance of 1-mm air and a container thickness of 6.35 mm.
IEEE Transactions on Antennas and Propagation, 2011
This work presents analysis of the behavior of open-ended coaxial near-field probes in the presen... more This work presents analysis of the behavior of open-ended coaxial near-field probes in the presence of -negative material. The effect of using negative material layers on the sensitivity is studied. It is shown that optimal conditions related to the thickness and constitutive parame- ters of the negative medium give rise to significant enhancement in probe sensitivity which allows the probe
IEEE Microwave and Wireless Components Letters, 2012
A new sensor based on complementary split-ring resonators is presented to detect sub-millimeter s... more A new sensor based on complementary split-ring resonators is presented to detect sub-millimeter surface cracks. The sensing mechanism is based on perturbing the electromagnetic field around an electrically small resonator, thus initiating a shift in the resonance frequency. The sensor is simple to fabricate and inexpensive as it is etched out in the ground plane of a microstrip-line using printed
The interest of this paper centers on fabrication and characterization and modeling of vortices i... more The interest of this paper centers on fabrication and characterization and modeling of vortices in high temperature superconducting thin films. As a first step, the magnetic vertices of the superconducting matrix were modeled. As a second, Bi-Sr-Ca-Cu-O thin films were grown using Pulsed Laser Ablation (PLD) on single crystal MgO substrates as magnetic templates for the potential use for Nano
This paper shows that DNG metamaterials enhance the sensitivity and range of the evanescent field... more This paper shows that DNG metamaterials enhance the sensitivity and range of the evanescent field probes. A conventional evanescent field probe produces all polarizations of the E and H fields. Therefore the experimental verification of the theory is not easy since a low loss, three dimensional DNG metamaterial is required. In this paper we propose a structure that can be used for verification of the sensitivity enhancement using a two dimensional DNG metamaterial. Theoretical results and numerical validation using the finite element method are presented.
In this paper, electromagnetic coupling between closely-spaced high-profile antennas is investiga... more In this paper, electromagnetic coupling between closely-spaced high-profile antennas is investigated with particular focus on multiple-input multiple-output (MIMO) systems. Monopole, and axial model helical antennas are considered in this study. Single- negative (SNG) metamaterials insulator were designed and placed between the antenna elements. Numerical and Experimental results show that better impedance matching can be achieved when using the magnetic resonators, as compared to the air case. Moreover, an almost 20 dB reduction in mutual coupling between antenna elements has been achieved.
In this paper, a new method based on strip line structures is presented for characterization of m... more In this paper, a new method based on strip line structures is presented for characterization of metamaterials. The proposed method is suitable for characterization of all types of artificial structures including Single Negative (SNG) and Double Negative (DNG) media. The new method has the advantages of easy fabrication and low cost, when compared to free space or the waveguide methods. Furthermore, it has the advantage of extracting both permittivity, e, and permeability, μ, with a single measurement, when compared to microstrip line method.
In this paper, we define a sensitivity measure for evanescent field detectors and show that a dis... more In this paper, we define a sensitivity measure for evanescent field detectors and show that a dispersive and lossless DNG slab increases the sensitivity. Since evanescent field based measurement modalities have limited range of detection, we analyze the effect of the DNG lens on the range of the evanescent field detections. By increasing their range, evanescent field probes can be used for noninvasive detection of material properties with an increased sensitivity for deeper regions.
In this paper, artificial magnetic resonators are used in order to reduce mutual coupling in Mult... more In this paper, artificial magnetic resonators are used in order to reduce mutual coupling in Multiple-input Multiple-Output (MIMO) systems. Split-ring resonator (SRR) inclusions are inserted between closely-spaced high-profile monopole antenna elements. It is shown that mutual coupling between the antenna elements can be reduced significantly by incorporating such magnetic inclusions. The magnetic materials work as insulators, and thus can be applied in a variety of antenna applications.
Near-field probes are attractive because they provide sub-wavelength resolution. Typical detectio... more Near-field probes are attractive because they provide sub-wavelength resolution. Typical detection using near field probes involves defects or irregularities present on the surface of the material. Sub-surface defects or irregularities are much more difficult to detect due to the fast decay of evanescent waves emanating from the probe. This work present novel probes employing metamaterial particles which work to substantially enhance the evanescent field energy in the vicinity of the probe, thereby increasing the sensitivity of the probe and enabling subsurface detection. Two experiments are presented where conducting metallic objects immersed in saline water and sand are detected. The results and findings presented here are expected to have strong implications in a wide range of sub surface detection challenges including detection of biological anomalies in human tissue, land mine detection, through-wall detection amongst other applications.
Recently, it was shown that single negative media can significantly enhance the sensitivity of ne... more Recently, it was shown that single negative media can significantly enhance the sensitivity of near-field probes. Inspired by this recent finding, a new near-field probe is proposed for noninvasive subsurface detection. The new probe uses a single split ring resonator (SRR) instead of a periodic arrangement of SRRs for negative material realization. Experimental tests were conducted to detect the presence of cracks on aluminum plates, the presence of small aluminum blocks located behind a layer of ground chicken (lossy medium), and the presence of a small aluminum block submerged in sodium chloride solution (lossy medium) with a salinity of 1%. Preliminary results show that the proposed near-field probe enables detection of electrically small targets buried in lossy media.
IEEE Transactions on Microwave Theory and Techniques, 2011
Most of the previous microwave near-field probes and imaging techniques focused on surface imagin... more Most of the previous microwave near-field probes and imaging techniques focused on surface imaging, providing ultra- high lateral resolution. Few microwave near-field probes were de- veloped for subsurface detection, offering both high lateral and depthresolutionwithvaryingdegreesofeffectiveness.Inthiswork, a novel microwave near-field probe using a single split-ring res- onator is introduced with the primary focus of subsurface detec- tion. The design is simple,
Recently, we showed that single negative media can significantly enhance the sensitivity of near-... more Recently, we showed that single negative media can significantly enhance the sensitivity of near-field probes. Inspired by this recent finding, we propose a new near-field probe that uses only one single split ring resonator instead of a periodic arrangement of these resonators. We show through numerical simulations that the new proposed probe lead to significant enhancement in the sensitivity as measured by the change in phase in the reflection coefficient. Experimental tests were conducted to detect the presence of a small aluminum block located behind a layer of ground chicken (lossy medium). Preliminary results show that with our new probe, a phase change in the reflection coefficient of 14 degrees can be achieved for 2 mm thick ground chicken and 6.24 mm aluminum cube at an operation frequency of 1.16 GHz.
The characteristic impedance and propagation constant formulation of conventional microstrip line... more The characteristic impedance and propagation constant formulation of conventional microstrip lines are analyzed for substrates made of negative materials. It is shown that the formulation can be used for negative material characterization when w/h is larger than 3. For narrow strips, the formulation is valid for low permittivity values. The method is a low cost and wide band characterization technique for negative material characterization.
Recently, it was shown that single negative media can significantly enhance the sensitivity of ne... more Recently, it was shown that single negative media can significantly enhance the sensitivity of near-field probes. Inspired by this recent finding, a new near-field probe is proposed for noninvasive subsurface detection. The new probe uses a single split ring resonator (SRR) instead of a periodic arrangement of SRRs for negative material realization. Experimental tests were conducted to detect the presence of cracks on aluminum plates, the presence of small aluminum blocks located behind a layer of ground chicken (lossy medium), and the presence of a small aluminum block submerged in sodium chloride solution (lossy medium) with a salinity of 1%. Preliminary results show that the proposed near-field probe enables detection of electrically small targets buried in lossy media.
IEEE Transactions on Antennas and Propagation, 2011
This work presents analysis of the behavior of open-ended coaxial near-field probes in the presen... more This work presents analysis of the behavior of open-ended coaxial near-field probes in the presence of -negative material. The effect of using negative material layers on the sensitivity is studied. It is shown that optimal conditions related to the thickness and constitutive parame- ters of the negative medium give rise to significant enhancement in probe sensitivity which allows the probe
In this work, we present the first experimental verification of the sensitivity improvement of ev... more In this work, we present the first experimental verification of the sensitivity improvement of evanescent field probes using single negative (SNG) metamaterials. The response of an electrically small probe to an electrically small target is investigated. The deviation in the phase of reflection coefficient due to the target is measured. When an SNG layer is employed, phase shift due to
In this work, a new EMP design is provided. By inserting an electrically small planar resonator a... more In this work, a new EMP design is provided. By inserting an electrically small planar resonator a unit cell of single negative media to a simple rectangular loop, the evanescent field in the near-field region is enhanced. As a result the sensitivity of the probe is improved significantly compared to a probe without SRR. The experiments in different media indicate
IEEE Transactions on Microwave Theory and Techniques, 2011
Most of the previous microwave near-field probes and imaging techniques focused on surface imagin... more Most of the previous microwave near-field probes and imaging techniques focused on surface imaging, providing ultrahigh lateral resolution. Few microwave near-field probes were developed for subsurface detection, offering both high lateral and depth resolution with varying degrees of effectiveness. In this work, a novel microwave near-field probe using a single split-ring resonator is introduced with the primary focus of subsurface detection. The design is simple, compact, inexpensive, and easy to fabricate using printed circuit board technology. Fourier spatial analysis of the field of the new probe reveals a substantial enhancement of the evanescent field, thus making a significant difference in subsurface detection. Experimental results illustrate that a small 3.24-mm aluminum block immersed in 1% sodium chloride (NaCl) solution and positioned 4 mm away from the surface was successfully detected using a probe operating at 1.218 GHz. For this particular experiment, where the size of the object was λ/74 , the detection ability of the new probe was tested using 2% and 3% NaCl solution as well. The phase changes due to the depth of the object demonstrate that the new probe is able to sense the presence of the same object in very lossy medium (3% NaCl whose loss tangent is approximately unity) with depth of 1-2 mm in spite of a standoff distance of 1-mm air and a container thickness of 6.35 mm.
IEEE Transactions on Antennas and Propagation, 2011
This work presents analysis of the behavior of open-ended coaxial near-field probes in the presen... more This work presents analysis of the behavior of open-ended coaxial near-field probes in the presence of -negative material. The effect of using negative material layers on the sensitivity is studied. It is shown that optimal conditions related to the thickness and constitutive parame- ters of the negative medium give rise to significant enhancement in probe sensitivity which allows the probe
IEEE Microwave and Wireless Components Letters, 2012
A new sensor based on complementary split-ring resonators is presented to detect sub-millimeter s... more A new sensor based on complementary split-ring resonators is presented to detect sub-millimeter surface cracks. The sensing mechanism is based on perturbing the electromagnetic field around an electrically small resonator, thus initiating a shift in the resonance frequency. The sensor is simple to fabricate and inexpensive as it is etched out in the ground plane of a microstrip-line using printed
Uploads
Papers