Scheimpflug LIDAR has attracted considerable attention in the recent years, and has been widely applied in many fields due to its infinite depth of field. In this study, we reconstruct a series of formulas to demonstrate the Scheimpflug principles, with reference at the hinge point. These formulas based on directly measurable parameters are simple in form. Base on this, we report a new calibration for the Scheimpflug system, without measuring the instrument parameters. We also confirm that the result of calibration is accordance with the actual setting of the system. To take full advantage of the infinite depth of field of the Scheimpflug system, we have designed and carried out the system, combining with a rotary stage, to obtain the entire volumetric profile for a target of interest in a cycle rotation. To the best of our knowledge, this is the first time Scheimpflug system is utilized to perform a three-dimensional volumetric profile measurement.
{"title":"A PARAMETER-FREE CALIBRATION PROCESS FOR A SCHEIMPFLUG LIDAR FOR VOLUMETRIC PROFILING","authors":"Longqiang Luo, Xiang Chen, Zhanpeng Xu, Shuo Li, Yaoran Sun, Sailing He","doi":"10.2528/pier20120701","DOIUrl":"https://doi.org/10.2528/pier20120701","url":null,"abstract":"Scheimpflug LIDAR has attracted considerable attention in the recent years, and has been widely applied in many fields due to its infinite depth of field. In this study, we reconstruct a series of formulas to demonstrate the Scheimpflug principles, with reference at the hinge point. These formulas based on directly measurable parameters are simple in form. Base on this, we report a new calibration for the Scheimpflug system, without measuring the instrument parameters. We also confirm that the result of calibration is accordance with the actual setting of the system. To take full advantage of the infinite depth of field of the Scheimpflug system, we have designed and carried out the system, combining with a rotary stage, to obtain the entire volumetric profile for a target of interest in a cycle rotation. To the best of our knowledge, this is the first time Scheimpflug system is utilized to perform a three-dimensional volumetric profile measurement.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89643141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A dual-mode hyperspectral imager using field of view scanning needs no moving macro parts. It could work in dual-mode (macro imaging and micro imaging) and is equipped with a conjugated camera for quick object-selection and focusing. By adjusting the imaging lens and achieving the image clarity on the conjugated camera, we could find the correct location and focusing of the ROIs simultaneously instead of inefficiently checking the hyperspectral image after the whole scanning process. The whole system was applied to the study of spectral characteristics of blood oxygen in human hands and the microscopic identification of algae, showing a great potential of clinical and marine applications of our system.
{"title":"DUAL-MODE HYPERSPECTRAL BIO-IMAGER WITH A CONJUGATED CAMERA FOR QUICK OBJECT-SELECTION AND FOCUSING","authors":"Xinli Yao, Shuo Li, Sailing He","doi":"10.2528/pier20080308","DOIUrl":"https://doi.org/10.2528/pier20080308","url":null,"abstract":"A dual-mode hyperspectral imager using field of view scanning needs no moving macro parts. It could work in dual-mode (macro imaging and micro imaging) and is equipped with a conjugated camera for quick object-selection and focusing. By adjusting the imaging lens and achieving the image clarity on the conjugated camera, we could find the correct location and focusing of the ROIs simultaneously instead of inefficiently checking the hyperspectral image after the whole scanning process. The whole system was applied to the study of spectral characteristics of blood oxygen in human hands and the microscopic identification of algae, showing a great potential of clinical and marine applications of our system.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85024160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Link, C. Montzka, T. Jagdhuber, S. Søbjærg, S. Dill, M. Peichl, T. Meyer, F. Jonard
This study investigates the sensitivity of L-band (1.41GHz) polarimetric brightness temperature signatures to oriented permittivity patterns, which can occur for example in the case of row and interrow soil moisture differences in agricultural fields. A field experiment and model simulations are conducted to verify the effects of such patterns on all four Stokes parameters. We find that for an artificial target resembling idealized model conditions, permittivity patterns lead to systematic brightness temperature modulations in dependency of the azimuthal look angle. For the specific field setup, modulations reach amplitudes of ∼ 4K and mostly affect h-polarized brightness temperatures as well as the first, second, and third Stokes parameters. Simulations of soil moisture patterns under idealized model conditions indicate even higher amplitudes (up to 60K for extreme cases). However, the effects occur only for permittivity layer widths of up to 8 cm (given the observing wavelength of 21 cm), which is lower than the row and interrow widths typically observed in agricultural settings. For this reason, and due to the idealized model geometry investigated here, future studies are needed to transfer the findings of this study to potential applications such as the sensing of oriented soil moisture patterns. Particular interest might lie in radiometry and reflectometry in lower frequency ranges such as P-band, where according to the threshold established here (8/21 wavelengths), permittivity layer widths of up to ∼ 45 cm could be observed.
{"title":"IMPACT OF PERMITTIVITY PATTERNS ON FULLY POLARIMETRIC BRIGHTNESS TEMPERATURE SIGNATURES AT L-BAND","authors":"M. Link, C. Montzka, T. Jagdhuber, S. Søbjærg, S. Dill, M. Peichl, T. Meyer, F. Jonard","doi":"10.2528/pier19080204","DOIUrl":"https://doi.org/10.2528/pier19080204","url":null,"abstract":"This study investigates the sensitivity of L-band (1.41GHz) polarimetric brightness temperature signatures to oriented permittivity patterns, which can occur for example in the case of row and interrow soil moisture differences in agricultural fields. A field experiment and model simulations are conducted to verify the effects of such patterns on all four Stokes parameters. We find that for an artificial target resembling idealized model conditions, permittivity patterns lead to systematic brightness temperature modulations in dependency of the azimuthal look angle. For the specific field setup, modulations reach amplitudes of ∼ 4K and mostly affect h-polarized brightness temperatures as well as the first, second, and third Stokes parameters. Simulations of soil moisture patterns under idealized model conditions indicate even higher amplitudes (up to 60K for extreme cases). However, the effects occur only for permittivity layer widths of up to 8 cm (given the observing wavelength of 21 cm), which is lower than the row and interrow widths typically observed in agricultural settings. For this reason, and due to the idealized model geometry investigated here, future studies are needed to transfer the findings of this study to potential applications such as the sensing of oriented soil moisture patterns. Particular interest might lie in radiometry and reflectometry in lower frequency ranges such as P-band, where according to the threshold established here (8/21 wavelengths), permittivity layer widths of up to ∼ 45 cm could be observed.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"106 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80892146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. E. Fajardo, J. Galv'an, F. Vericat, C. M. Carlevaro, R. Irastorza
An inverse method for parameters estimation of infinite cylinders (the dielectric properties, location, and radius) in two dimensions from amplitude-only microwave information is presented. To this end two different Artificial Neural Networks (ANN) topologies are compared; Multilayer Perceptron (MLP) and a Convolutional Neural Network (CNN). Several simulations employing the Finite Differences in Time Domain (FDTD) method are performed to solve the direct electromagnetic problem and generate training, validation, and test sets for the ANN models. The magnitude of the mean errors in estimating the position and size of the cylinder are up to (1.9 $pm$ 3.3) mm and (0.2 $pm$ 0.8) mm for the MLP and CNN, respectively. The magnitude of the mean percentage relative errors in estimating the dielectric properties of the cylinder are up to (6.5 $pm$ 13.8) % and (0.0 $pm$ 7.2) % for the MLP and CNN, respectively. The errors in the parameters estimation from the MLP model are low, however, significantly lower errors were obtained with the CNN model. A validation example is shown using a simulation in three dimensions. Measurement examples with homogeneous and heterogeneous cylinders are presented aiming to prove the feasibility of the described method.
{"title":"PHASELESS MICROWAVE IMAGING OF DIELECTRIC CYLINDERS: AN ARTIFICIAL NEURAL NETWORKS-BASED APPROACH","authors":"J. E. Fajardo, J. Galv'an, F. Vericat, C. M. Carlevaro, R. Irastorza","doi":"10.2528/PIER19080610","DOIUrl":"https://doi.org/10.2528/PIER19080610","url":null,"abstract":"An inverse method for parameters estimation of infinite cylinders (the dielectric properties, location, and radius) in two dimensions from amplitude-only microwave information is presented. To this end two different Artificial Neural Networks (ANN) topologies are compared; Multilayer Perceptron (MLP) and a Convolutional Neural Network (CNN). Several simulations employing the Finite Differences in Time Domain (FDTD) method are performed to solve the direct electromagnetic problem and generate training, validation, and test sets for the ANN models. The magnitude of the mean errors in estimating the position and size of the cylinder are up to (1.9 $pm$ 3.3) mm and (0.2 $pm$ 0.8) mm for the MLP and CNN, respectively. The magnitude of the mean percentage relative errors in estimating the dielectric properties of the cylinder are up to (6.5 $pm$ 13.8) % and (0.0 $pm$ 7.2) % for the MLP and CNN, respectively. The errors in the parameters estimation from the MLP model are low, however, significantly lower errors were obtained with the CNN model. A validation example is shown using a simulation in three dimensions. Measurement examples with homogeneous and heterogeneous cylinders are presented aiming to prove the feasibility of the described method.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87195499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently we derived generalized sheet transition conditions (GSTCs) for electromagnetic fields at the surface of a metascreen (a metasurface with a ``fishnet'' structure, i.~e., a periodic array of arbitrary spaced apertures in a relatively impenetrable surface). The parameters in these GSTCs are interpreted as effective surface susceptibilities and surface porosities, which themselves are related to the geometry of the apertures that constitute the metascreen. In this paper, we use these GSTCs to derive the plane-wave reflection ($R$) and transmission ($T$) coefficients of a symmetric metascreen, expressed in terms of these surface parameters. From these equations, we develop a retrieval approach for determining the uniquely defined effective surface susceptibilities and surface porosities that characterize the metascreen from measured or simulated data for the $R$ and $T$ coefficients. We present the retrieved surface parameters for metascreens composed of five different types of apertures (circular holes, square holes, crosses, slots, and a square aperture filled with a high-contrast dielectric). The last example exhibits interesting resonances at frequencies where no resonances exist when the aperture is not filled, which opens up the possibility of designing metasurfaces with unique filtering properties. The retrieved surface parameters are validated by comparing them to other approaches.
{"title":"RETRIEVAL APPROACH FOR DETERMINING SURFACE SUSCEPTIBILITIES AND SURFACE POROSITIES OF A SYMMETRIC METASCREEN FROM REFLECTION AND TRANSMISSION COEFFICIENTS","authors":"C. Holloway, E. Kuester, Abdulaziz H. Haddab","doi":"10.2528/pier19022305","DOIUrl":"https://doi.org/10.2528/pier19022305","url":null,"abstract":"Recently we derived generalized sheet transition conditions (GSTCs) for electromagnetic fields at the surface of a metascreen (a metasurface with a ``fishnet'' structure, i.~e., a periodic array of arbitrary spaced apertures in a relatively impenetrable surface). The parameters in these GSTCs are interpreted as effective surface susceptibilities and surface porosities, which themselves are related to the geometry of the apertures that constitute the metascreen. In this paper, we use these GSTCs to derive the plane-wave reflection ($R$) and transmission ($T$) coefficients of a symmetric metascreen, expressed in terms of these surface parameters. From these equations, we develop a retrieval approach for determining the uniquely defined effective surface susceptibilities and surface porosities that characterize the metascreen from measured or simulated data for the $R$ and $T$ coefficients. We present the retrieved surface parameters for metascreens composed of five different types of apertures (circular holes, square holes, crosses, slots, and a square aperture filled with a high-contrast dielectric). The last example exhibits interesting resonances at frequencies where no resonances exist when the aperture is not filled, which opens up the possibility of designing metasurfaces with unique filtering properties. The retrieved surface parameters are validated by comparing them to other approaches.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77099229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. S. M. Mollaei, S. Kurdjumov, A. Hurshkainen, C. Simovski
We report decoupling of two closely located resonant dipole antennas dedicated for ultra-high field magnetic resonance imaging (MRI). We show that a scatterer slightly raised over the plane of antennas grants a sufficient decoupling even for antennas separated by very small gap (below 1/30 of the wavelength). We compare the operation of two decoupling scatterers. One of them is a shortcut resonant dipole and another is a split-loop resonator (SLR). Previously, we have shown that the SLR offers a wider operational band than the dipole and the same level of decoupling. However, it was so for an array in free space. The presence of the body phantom drastically changes the decoupling conditions. Moreover, the requirement to minimize the parasitic scattering from the decoupling element into the body makes the decoupling dipole much more advantageous compared to the SLR.
{"title":"DECOUPLING OF TWO CLOSELY LOCATED DIPOLES BY A SINGLE PASSIVE SCATTERER FOR ULTRA-HIGH FIELD MRI","authors":"M. S. M. Mollaei, S. Kurdjumov, A. Hurshkainen, C. Simovski","doi":"10.2528/PIER18101703","DOIUrl":"https://doi.org/10.2528/PIER18101703","url":null,"abstract":"We report decoupling of two closely located resonant dipole antennas dedicated for ultra-high field magnetic resonance imaging (MRI). We show that a scatterer slightly raised over the plane of antennas grants a sufficient decoupling even for antennas separated by very small gap (below 1/30 of the wavelength). We compare the operation of two decoupling scatterers. One of them is a shortcut resonant dipole and another is a split-loop resonator (SLR). Previously, we have shown that the SLR offers a wider operational band than the dipole and the same level of decoupling. However, it was so for an array in free space. The presence of the body phantom drastically changes the decoupling conditions. Moreover, the requirement to minimize the parasitic scattering from the decoupling element into the body makes the decoupling dipole much more advantageous compared to the SLR.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84461723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Refractive index (RI) measurements find extensive use in biochemical sensing field. However, currently available RI sensors exhibit excessive temperature crosstalk and have low sensitivity in the low RI range. To solve this, a high-sensitivity and temperature-insensitive refractometer based on a tapered no-core-hollow-core fiber (TNHF) structure is proposed for low-range RI measurement. The TNHF comprises two Mach-Zehnder interferometers that are introduced within the tapered nocore fiber and hollow-core fiber, thereby establishing a composite interference. The results of an experimental evaluation demonstrate that maximum sensitivities of 482.74 nm/RIU within an RI range of 1.335 ∼ 1.3462 can be achieved, which is greater than that achieved using a traditional modal interferometer structure. Significantly, the refractometer exhibits ultra-low temperature sensitivities of 0.062 dB/◦C and 6.5 pm/◦C, which can alleviate the temperature crosstalk. The refractometer can be realistically applied in many fields requiring high precision RI measurement due to its advantages of low cost, ease of manufacture, high sensitivity, and temperature insensitivity.
{"title":"HIGH-SENSITIVITY AND TEMPERATURE-INSENSITIVE REFRACTOMETER BASED ON TNHF STRUCTURE FOR LOW-RANGE REFRACTIVE INDEX MEASUREMENT","authors":"F. Wang, Kaibo Pang, Tao Ma, X. Wang, Yufang Liu","doi":"10.2528/pier19102301","DOIUrl":"https://doi.org/10.2528/pier19102301","url":null,"abstract":"Refractive index (RI) measurements find extensive use in biochemical sensing field. However, currently available RI sensors exhibit excessive temperature crosstalk and have low sensitivity in the low RI range. To solve this, a high-sensitivity and temperature-insensitive refractometer based on a tapered no-core-hollow-core fiber (TNHF) structure is proposed for low-range RI measurement. The TNHF comprises two Mach-Zehnder interferometers that are introduced within the tapered nocore fiber and hollow-core fiber, thereby establishing a composite interference. The results of an experimental evaluation demonstrate that maximum sensitivities of 482.74 nm/RIU within an RI range of 1.335 ∼ 1.3462 can be achieved, which is greater than that achieved using a traditional modal interferometer structure. Significantly, the refractometer exhibits ultra-low temperature sensitivities of 0.062 dB/◦C and 6.5 pm/◦C, which can alleviate the temperature crosstalk. The refractometer can be realistically applied in many fields requiring high precision RI measurement due to its advantages of low cost, ease of manufacture, high sensitivity, and temperature insensitivity.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78310017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Most imaging modalities image an object’s interior while all instrumentation, including sources and receivers, is externally located. One notable exception is ultra-sound (US), which can be miniaturized sufficiently to locate a US transducer within an object and gather data for image reconstruction. Another is cross-borehole geophysical imaging. The goal of any internal imaging modality is to provide images of greater fidelity while avoiding interfering structures. Due to the bulkiness of multi-coil magnetic induction tomography (MIT), transmitting and receiving coils are never placed within small targets (e.g., a human body). Here, we demonstrate a novel implementation of single-coil MIT that performs a scan all while the coil is located within the interior of a small, labcreated phantom consisting of salt-doped agarose. Phantom geometry is annular, consisting of a 6.0 cm diameter channel of depth 5.5 cm surrounded by a 3.0 cm thick cylindrical wall. An embedded, centrally located agarose gel annulus, 2.0 cm thick, is doped with sufficient NaCl to elevate its conductivity above that of surrounding agarose. The resulting nearly axisymmetric phantoms consist of material having conductivity ranging from 0.11 to 10.55 S/m. A scan is accomplished robotically, with the coil stubmounted on the positioning head of a 3-axis controller that positions the planar circular loop coil into 360 or 720 preset internal positions. Image reconstruction from gathered data is shown to correctly reveal the location, size and conductivity of the approximately axisymmetric inclusion.
{"title":"INTERNAL MAGNETIC INDUCTION TOMOGRAPHY USING A SINGLE COIL","authors":"J. Feldkamp, S. Quirk","doi":"10.2528/PIER18120408","DOIUrl":"https://doi.org/10.2528/PIER18120408","url":null,"abstract":"Most imaging modalities image an object’s interior while all instrumentation, including sources and receivers, is externally located. One notable exception is ultra-sound (US), which can be miniaturized sufficiently to locate a US transducer within an object and gather data for image reconstruction. Another is cross-borehole geophysical imaging. The goal of any internal imaging modality is to provide images of greater fidelity while avoiding interfering structures. Due to the bulkiness of multi-coil magnetic induction tomography (MIT), transmitting and receiving coils are never placed within small targets (e.g., a human body). Here, we demonstrate a novel implementation of single-coil MIT that performs a scan all while the coil is located within the interior of a small, labcreated phantom consisting of salt-doped agarose. Phantom geometry is annular, consisting of a 6.0 cm diameter channel of depth 5.5 cm surrounded by a 3.0 cm thick cylindrical wall. An embedded, centrally located agarose gel annulus, 2.0 cm thick, is doped with sufficient NaCl to elevate its conductivity above that of surrounding agarose. The resulting nearly axisymmetric phantoms consist of material having conductivity ranging from 0.11 to 10.55 S/m. A scan is accomplished robotically, with the coil stubmounted on the positioning head of a 3-axis controller that positions the planar circular loop coil into 360 or 720 preset internal positions. Image reconstruction from gathered data is shown to correctly reveal the location, size and conductivity of the approximately axisymmetric inclusion.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90070384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, by applying topological theory, we evaluate some left-handed unit structures. Based on the classification of topological deformation, the laws and characteristics of potential electromagnetic parameters are captured. The original left-handed material unit is realized by using a circular C-shaped coupling ring, whose whole size is 10×10×0.5 mm3. Through three kinds of topological deformations, to explore the influence of topology on antenna performance, the electromagnetic parameters and left-handed characteristics of the original and modified units are compared and analyzed. For the designed handshake-shaped unit structure, simulation analysis predicts that dual-frequency, or even multi-band left-handed characteristics, can be achieved. To expand the structural performance of the handshake-shaped unit, an annular line for coupling enhancement is added inside the U-shaped structure to form an integrally coupled annular unit structure. Simulation results show that, with amplitudes of reflection coefficients of −27.1 dB and −14.5 dB, the resonance points of the improved unit structure are 3.57 GHz and 5.64 GHz, respectively. Loading the unit structure with a dual-band lefthanded characteristic, a UWB antenna is designed and analyzed in detail. Through simulation, antenna performance is most affected by interference within the range of 2.5 ∼ 5.0 GHz, which coincides with the double negative frequency band of the loaded left-handed structural unit. The notch frequency band of the designed UWB antenna, which is much wider than traditional notch antennas, is 3.62 ∼ 4.54 GHz, with a notch bandwidth of 920 MHz.
{"title":"PERFORMANCE IMPROVEMENT AND ANTENNA DESIGN OF LEFT-HANDED MATERIAL UNITS BASED ON TOPOLOGICAL DEFORMATIONS","authors":"B. You, M. Dong, Jianhua Zhou, Haike Xu","doi":"10.2528/pier19011603","DOIUrl":"https://doi.org/10.2528/pier19011603","url":null,"abstract":"In this paper, by applying topological theory, we evaluate some left-handed unit structures. Based on the classification of topological deformation, the laws and characteristics of potential electromagnetic parameters are captured. The original left-handed material unit is realized by using a circular C-shaped coupling ring, whose whole size is 10×10×0.5 mm3. Through three kinds of topological deformations, to explore the influence of topology on antenna performance, the electromagnetic parameters and left-handed characteristics of the original and modified units are compared and analyzed. For the designed handshake-shaped unit structure, simulation analysis predicts that dual-frequency, or even multi-band left-handed characteristics, can be achieved. To expand the structural performance of the handshake-shaped unit, an annular line for coupling enhancement is added inside the U-shaped structure to form an integrally coupled annular unit structure. Simulation results show that, with amplitudes of reflection coefficients of −27.1 dB and −14.5 dB, the resonance points of the improved unit structure are 3.57 GHz and 5.64 GHz, respectively. Loading the unit structure with a dual-band lefthanded characteristic, a UWB antenna is designed and analyzed in detail. Through simulation, antenna performance is most affected by interference within the range of 2.5 ∼ 5.0 GHz, which coincides with the double negative frequency band of the loaded left-handed structural unit. The notch frequency band of the designed UWB antenna, which is much wider than traditional notch antennas, is 3.62 ∼ 4.54 GHz, with a notch bandwidth of 920 MHz.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73333190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qiuqiang Zhan, Xin Zhang, Baoju Wang, Nana Li, Sailing He
Layered molybdenum disulphide (MoS2) can efficiently emit photoluminescence (PL) excited by visible light. However, one-photon PL of MoS2 for bioimaging purposes suffers from strong autofluorescence and ion-induced PL quenching. Herein, we report single layer chitosan decorated MoS2 nanosheets as nonbleaching and nonblinking optical nanoprobes under near infrared femtosecond laser excitation and their applications for two photon luminescence (TPL) and second harmonic generation (SHG) bioimaging. The TPL can resist the ion-induced quenching by the cellular membrane. The proposed TPL and SHG of single layer MoS2 show great potential for real-time, deep and multiphoton bioimaging.
{"title":"TWO-PHOTON LUMINESCENCE AND SECOND HARMONIC GENERATION OF SINGLE LAYER MOLYBDENUM DISULPHIDE NANOPROBE FOR NONBLEACHING AND NONBLINKING OPTICAL BIOIMAGING","authors":"Qiuqiang Zhan, Xin Zhang, Baoju Wang, Nana Li, Sailing He","doi":"10.2528/pier19072502","DOIUrl":"https://doi.org/10.2528/pier19072502","url":null,"abstract":"Layered molybdenum disulphide (MoS2) can efficiently emit photoluminescence (PL) excited by visible light. However, one-photon PL of MoS2 for bioimaging purposes suffers from strong autofluorescence and ion-induced PL quenching. Herein, we report single layer chitosan decorated MoS2 nanosheets as nonbleaching and nonblinking optical nanoprobes under near infrared femtosecond laser excitation and their applications for two photon luminescence (TPL) and second harmonic generation (SHG) bioimaging. The TPL can resist the ion-induced quenching by the cellular membrane. The proposed TPL and SHG of single layer MoS2 show great potential for real-time, deep and multiphoton bioimaging.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84994522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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