This paper investigates an FDTD modeling method for precisely calculating the characteristics of a single, that is, a nonperiodic antenna located above a metasurface that consists of an infinite periodic conducting element on a flat dielectric substrate. The original FDTD method requires enormous computational resources to analyze such structures because an appropriate periodic boundary condition (PBC) is not supported, and a brute force approach has to be used for this reason. Another option is to use the array scanning method in which a single source is synthesized from a superposition of infinite phased array of point sources. In this method, some problems such as a mutual coupling between the single antenna and the metasurface, a computational error contained in a numerical integration over the Brillouin zone and so on have not been resolved yet. In order to resolve these difficulties and to reduce computational resources, a surface impedance boundary condition (SIBC) is incorporated into the FDTD method in this paper. The validity of the method is numerically confirmed by calculating an input impedance and a radiation pattern of a horizontal dipole antenna located above the metasurface.
{"title":"FDTD modeling of nonperiodic antenna located above metasurface using surface impedance boundary condition","authors":"T. Uno, T. Arima, Akihide Kurahara","doi":"10.1051/EPJAM/2019014","DOIUrl":"https://doi.org/10.1051/EPJAM/2019014","url":null,"abstract":"This paper investigates an FDTD modeling method for precisely calculating the characteristics of a single, that is, a nonperiodic antenna located above a metasurface that consists of an infinite periodic conducting element on a flat dielectric substrate. The original FDTD method requires enormous computational resources to analyze such structures because an appropriate periodic boundary condition (PBC) is not supported, and a brute force approach has to be used for this reason. Another option is to use the array scanning method in which a single source is synthesized from a superposition of infinite phased array of point sources. In this method, some problems such as a mutual coupling between the single antenna and the metasurface, a computational error contained in a numerical integration over the Brillouin zone and so on have not been resolved yet. In order to resolve these difficulties and to reduce computational resources, a surface impedance boundary condition (SIBC) is incorporated into the FDTD method in this paper. The validity of the method is numerically confirmed by calculating an input impedance and a radiation pattern of a horizontal dipole antenna located above the metasurface.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/EPJAM/2019014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57822726","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, we introduce and review the zeroth-order resonator (ZOR) antennas with outstanding characteristics including various applications that have been researched so far. Since the zeroth-order resonance frequency is independent of a physical length of antenna, the ZOR antenna can theoretically be designed quite small and have a possibility to apply to considerably lots of applications. First, we have presented the ZOR antennas implemented by double-negative (DNG), epsilon-negative (ENG), and mu-negative (MNG) transmission lines. Then, the research related on extremely small, wide beamwidth, wideband, and circularly polarized (CP) ZOR antennas have been continuously carried out. Based on a series of these studies, the ZOR antennas were utilized for various applications such as a wireless power transfer (WPT), a compact controlled reception pattern antenna (CRPA), a penta-band mobile antenna, and a wide steering array antenna.
{"title":"Compact zeroth-order resonator (ZOR) antennas","authors":"Jae‐Gon Lee, Jeong‐Hae Lee","doi":"10.1051/EPJAM/2019002","DOIUrl":"https://doi.org/10.1051/EPJAM/2019002","url":null,"abstract":"In this paper, we introduce and review the zeroth-order resonator (ZOR) antennas with outstanding characteristics including various applications that have been researched so far. Since the zeroth-order resonance frequency is independent of a physical length of antenna, the ZOR antenna can theoretically be designed quite small and have a possibility to apply to considerably lots of applications. First, we have presented the ZOR antennas implemented by double-negative (DNG), epsilon-negative (ENG), and mu-negative (MNG) transmission lines. Then, the research related on extremely small, wide beamwidth, wideband, and circularly polarized (CP) ZOR antennas have been continuously carried out. Based on a series of these studies, the ZOR antennas were utilized for various applications such as a wireless power transfer (WPT), a compact controlled reception pattern antenna (CRPA), a penta-band mobile antenna, and a wide steering array antenna.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/EPJAM/2019002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57822570","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}
Here an electrically small multiband antenna based on spoof localized surface plasmons (LSPs) has been proposed using corrugated ring resonator printed on a thin dielectric substrate with complementary metallic spiral structure (MSS) on the ground plane. It has been found that the resonant frequencies of spoof LSPs redshift by tuning the arm length of the complementary MSS, which leads to the miniaturization of the antenna. The fabricated multiband antenna has a small size of only 0.11λ × 0.1λ, covering GSM900, GSM1800, and WiFi bands. Such electrically small multiband antenna with high gain is necessary for efficient wireless energy harvesting (WEH), which can find more applications in various areas including Internet of Things (IoT), wireless sensor network (WSN), etc.
{"title":"Electrically small multiband antenna based on spoof localized surface plasmons","authors":"Rong Lin Shao, Bo Li, Liu Yang, Y. Zhou","doi":"10.1051/EPJAM/2019009","DOIUrl":"https://doi.org/10.1051/EPJAM/2019009","url":null,"abstract":"Here an electrically small multiband antenna based on spoof localized surface plasmons (LSPs) has been proposed using corrugated ring resonator printed on a thin dielectric substrate with complementary metallic spiral structure (MSS) on the ground plane. It has been found that the resonant frequencies of spoof LSPs redshift by tuning the arm length of the complementary MSS, which leads to the miniaturization of the antenna. The fabricated multiband antenna has a small size of only 0.11λ × 0.1λ, covering GSM900, GSM1800, and WiFi bands. Such electrically small multiband antenna with high gain is necessary for efficient wireless energy harvesting (WEH), which can find more applications in various areas including Internet of Things (IoT), wireless sensor network (WSN), etc.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/EPJAM/2019009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57822705","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}
The scattering properties of a range of symmetric and asymmetric active coated nano rod antennas are investigated numerically. The active nano rods are composed of a silica dioxide nano-core coated with a silver nano-shell, and with a canonical gain model implemented into their nano-core regions. The asymmetric nano rods are obtained through suitable perforations of their nano-shell and/or nano-core regions. In all cases, active nano rods are found to exhibit super-resonant phenomena with significantly enhanced scattered fields for an incident plane wave having the magnetic field parallel to the rod axis. While the dipole-mode response in the symmetric cases is only weakly directive, the asymmetric cases stimulate an abundant emission of higher order modes furnishing rather enhanced and directive near-fields. As the length of the symmetric nano rods decreases, more gain is needed to achieve a super-resonant response, which also was found to be blue-shifted. For asymmetric cases, the gain was lowered, and the response got blue-shifted as the asymmetry increased. The proposed active nano rod antennas provide a new class of antennas with desirable wavelength tunability and polarization-dependent scattering properties; this makes them interesting candidates for many nano-photonic applications. Moreover, the proposed geometries bridge the important gap between the two often considered canonical geometries, namely, spherical and infinitely long cylindrical particles. The detailed knowledge of gain values and resonant wavelengths provided in here is crucial for a successful combination of such particles with realistic gain materials.
{"title":"Active coated nano rod antennas for enhanced and directive scattering phenomena","authors":"S. Arslanagić, R. E. Jacobsen","doi":"10.1051/epjam/2019016","DOIUrl":"https://doi.org/10.1051/epjam/2019016","url":null,"abstract":"The scattering properties of a range of symmetric and asymmetric active coated nano rod antennas are investigated numerically. The active nano rods are composed of a silica dioxide nano-core coated with a silver nano-shell, and with a canonical gain model implemented into their nano-core regions. The asymmetric nano rods are obtained through suitable perforations of their nano-shell and/or nano-core regions. In all cases, active nano rods are found to exhibit super-resonant phenomena with significantly enhanced scattered fields for an incident plane wave having the magnetic field parallel to the rod axis. While the dipole-mode response in the symmetric cases is only weakly directive, the asymmetric cases stimulate an abundant emission of higher order modes furnishing rather enhanced and directive near-fields. As the length of the symmetric nano rods decreases, more gain is needed to achieve a super-resonant response, which also was found to be blue-shifted. For asymmetric cases, the gain was lowered, and the response got blue-shifted as the asymmetry increased. The proposed active nano rod antennas provide a new class of antennas with desirable wavelength tunability and polarization-dependent scattering properties; this makes them interesting candidates for many nano-photonic applications. Moreover, the proposed geometries bridge the important gap between the two often considered canonical geometries, namely, spherical and infinitely long cylindrical particles. The detailed knowledge of gain values and resonant wavelengths provided in here is crucial for a successful combination of such particles with realistic gain materials.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjam/2019016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57822767","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}
Metamaterial ferrites or metaferrites are artificial magnetic materials which mimic the properties of ferrites at a certain frequency operation. Antenna engineers are therefore able to design and create artificial substrates which replicate the electrical properties of ferrites without actually using any in the construction. This is advantageous as ferrites can offer performance improvements to microstrip antennas, such as size reduction and wideband impedance matching. In this paper, a metaferrite substrate designed by the use of a genetic algorithm is presented. The metaferrite was optimized in order to obtain the magnetic responses at 9GHz, for its use as the substrate of a microstrip antenna. As an example, a U-slot patch antenna based on the metaferrite is demonstrated, which can achieve stable radiation and 14 dB radar cross section (RCS) reduction performance in the measurement.
{"title":"U-slot patch antenna with low RCS based on a metaferrite substrate","authors":"Yujie Liu, P. Beal, H. Giddens, Y. Hao","doi":"10.1051/epjam/2019020","DOIUrl":"https://doi.org/10.1051/epjam/2019020","url":null,"abstract":"Metamaterial ferrites or metaferrites are artificial magnetic materials which mimic the properties of ferrites at a certain frequency operation. Antenna engineers are therefore able to design and create artificial substrates which replicate the electrical properties of ferrites without actually using any in the construction. This is advantageous as ferrites can offer performance improvements to microstrip antennas, such as size reduction and wideband impedance matching. In this paper, a metaferrite substrate designed by the use of a genetic algorithm is presented. The metaferrite was optimized in order to obtain the magnetic responses at 9GHz, for its use as the substrate of a microstrip antenna. As an example, a U-slot patch antenna based on the metaferrite is demonstrated, which can achieve stable radiation and 14 dB radar cross section (RCS) reduction performance in the measurement.","PeriodicalId":43689,"journal":{"name":"EPJ Applied Metamaterials","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjam/2019020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57822840","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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