The Experts below are selected from a list of 7263 Experts worldwide ranked by ideXlab platform
George V Eleftheriades - One of the best experts on this subject based on the ideXlab platform.
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omega bianisotropic Wire Loop huygens metasurface for reflectionless wide angle refraction
IEEE Transactions on Antennas and Propagation, 2020Co-Authors: Michael Chen, George V EleftheriadesAbstract:Huygens’ metasurfaces, typically designed using sub-wavelength unit cells, allow the arbitrary control of electromagnetic waves. Two well-known unit-cell topologies are the Wire-Loop and stacked-layer designs. The Wire-Loop unit cell utilizes a conductive Wire and Loop to control its electric and magnetic responses, while the stacked-layer unit cell utilizes cascaded impedance sheets. Due to their versatility, Huygens’ metasurfaces have been used for numerous applications. One interesting application has been perfect or reflectionless wide-angle refraction. In recent years, it was shown that for perfect refraction, omega-bianisotropy was required in Huygens’ metasurfaces. To realize omega-bianisotropic designs, asymmetric unit cells were proposed and demonstrated utilizing stacked-layer unit cells. However, an omega-bianisotropic Wire-Loop unit cell for modulated Huygens’ metasurfaces has yet to be demonstrated. This article demonstrates the design, simulation results, and measurements of an omega-bianisotropic Wire-Loop Huygens’ metasurface for reflectionless wide-angle refraction of 71.8° at 20 GHz. The design and simulation results of both TE and TM transverse-electric (TE) and transverse-magnetic (TM) designs are presented. Additionally, an optimized TM metasurface is experimentally verified through a combination of quasi-optical and far-field measurements. The presented results demonstrate negligible reflections, high scattered refraction efficiency, and a 0.7 GHz bandwidth, which validates the Wire-Loop unit-cell topology for realizing omega-bianisotropic Huygens’ metasurfaces.
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omega bianisotropic Wire Loop huygens metasurface for wide angle refraction
International Symposium on Antennas and Propagation, 2019Co-Authors: Michael Chen, George V EleftheriadesAbstract:Huygens’ metasurfaces allow the arbitrary control of electromagnetic waves by utilizing both electric and magnetic currents. These electrically thin structures interact with incident electromagnetic waves on a sub-wavelength scale to produce desired wave effects. To realize Huygens’ metasurfaces, different unit cell topologies such as the Wire-Loop or the stacked-layer configurations can be utilized. In recent years, Omega-bianisotropic Huygens’ metasurfaces have been demonstrated utilizing asymmetric stacked-layer unit cells, allowing the realization of reflectionless transformations. However, an Omega-bianisotropic version of the Wire-Loop unit cell has yet to be demonstrated for modulated Huygens’ metasurfaces. In this paper, the design and fullwave simulation results of Omega-bianisotropic Huygens’ Wire-Loop metasurfaces for reflectionless wide-angle refraction from normal incidence to 71.8° for both transverse-electric and transverse-magnetic polarizations centered at 20GHz are presented.
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bianisotropic huygens metasurface for wideband impedance matching between two dielectric media
IEEE Transactions on Antennas and Propagation, 2018Co-Authors: Ayman H Dorrah, Michael Chen, George V EleftheriadesAbstract:There is an established equivalence between Huygens’ metasurfaces and lattice networks. This paper proposes an extension to this equivalence for bianisotropic Huygens’ metasurfaces, where bianisotropy refers to the magnetoelectric coupling between the effective electric and magnetic responses. A modified version of the lattice network is proposed that exhibits a one-to-one mapping to the bianisotropic sheet transition conditions by incorporating ideal transformers. A possible realization of bianisotropic Huygens’ unit cells is also proposed that relies on offsetting the Wire with respect to the Loop in the Wire/Loop topology. This is followed by deriving analytical expressions for the image impedances and the corresponding transfer function of bianisotropic Huygens’ metasurfaces. Inverse analytical expressions are also derived that govern the required effective electric and magnetic responses and the magnetoelectric coupling for achieving wideband electrical transparency (symmetric case) and wideband impedance transformation (bianisotropic case) with these Huygens’ metasurface unit cells. Moreover, it is shown that these expressions can be realized with transmission-line stubs. These expressions are then used to design subwavelength thin Huygens’ metasurfaces immersed in an air gap between two dielectric media. It is shown, through full-wave simulations, that wideband electrical transparency and impedance transformation are realized for a normally impinging plane wave.
Michael Chen - One of the best experts on this subject based on the ideXlab platform.
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omega bianisotropic Wire Loop huygens metasurface for reflectionless wide angle refraction
IEEE Transactions on Antennas and Propagation, 2020Co-Authors: Michael Chen, George V EleftheriadesAbstract:Huygens’ metasurfaces, typically designed using sub-wavelength unit cells, allow the arbitrary control of electromagnetic waves. Two well-known unit-cell topologies are the Wire-Loop and stacked-layer designs. The Wire-Loop unit cell utilizes a conductive Wire and Loop to control its electric and magnetic responses, while the stacked-layer unit cell utilizes cascaded impedance sheets. Due to their versatility, Huygens’ metasurfaces have been used for numerous applications. One interesting application has been perfect or reflectionless wide-angle refraction. In recent years, it was shown that for perfect refraction, omega-bianisotropy was required in Huygens’ metasurfaces. To realize omega-bianisotropic designs, asymmetric unit cells were proposed and demonstrated utilizing stacked-layer unit cells. However, an omega-bianisotropic Wire-Loop unit cell for modulated Huygens’ metasurfaces has yet to be demonstrated. This article demonstrates the design, simulation results, and measurements of an omega-bianisotropic Wire-Loop Huygens’ metasurface for reflectionless wide-angle refraction of 71.8° at 20 GHz. The design and simulation results of both TE and TM transverse-electric (TE) and transverse-magnetic (TM) designs are presented. Additionally, an optimized TM metasurface is experimentally verified through a combination of quasi-optical and far-field measurements. The presented results demonstrate negligible reflections, high scattered refraction efficiency, and a 0.7 GHz bandwidth, which validates the Wire-Loop unit-cell topology for realizing omega-bianisotropic Huygens’ metasurfaces.
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omega bianisotropic Wire Loop huygens metasurface for wide angle refraction
International Symposium on Antennas and Propagation, 2019Co-Authors: Michael Chen, George V EleftheriadesAbstract:Huygens’ metasurfaces allow the arbitrary control of electromagnetic waves by utilizing both electric and magnetic currents. These electrically thin structures interact with incident electromagnetic waves on a sub-wavelength scale to produce desired wave effects. To realize Huygens’ metasurfaces, different unit cell topologies such as the Wire-Loop or the stacked-layer configurations can be utilized. In recent years, Omega-bianisotropic Huygens’ metasurfaces have been demonstrated utilizing asymmetric stacked-layer unit cells, allowing the realization of reflectionless transformations. However, an Omega-bianisotropic version of the Wire-Loop unit cell has yet to be demonstrated for modulated Huygens’ metasurfaces. In this paper, the design and fullwave simulation results of Omega-bianisotropic Huygens’ Wire-Loop metasurfaces for reflectionless wide-angle refraction from normal incidence to 71.8° for both transverse-electric and transverse-magnetic polarizations centered at 20GHz are presented.
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bianisotropic huygens metasurface for wideband impedance matching between two dielectric media
IEEE Transactions on Antennas and Propagation, 2018Co-Authors: Ayman H Dorrah, Michael Chen, George V EleftheriadesAbstract:There is an established equivalence between Huygens’ metasurfaces and lattice networks. This paper proposes an extension to this equivalence for bianisotropic Huygens’ metasurfaces, where bianisotropy refers to the magnetoelectric coupling between the effective electric and magnetic responses. A modified version of the lattice network is proposed that exhibits a one-to-one mapping to the bianisotropic sheet transition conditions by incorporating ideal transformers. A possible realization of bianisotropic Huygens’ unit cells is also proposed that relies on offsetting the Wire with respect to the Loop in the Wire/Loop topology. This is followed by deriving analytical expressions for the image impedances and the corresponding transfer function of bianisotropic Huygens’ metasurfaces. Inverse analytical expressions are also derived that govern the required effective electric and magnetic responses and the magnetoelectric coupling for achieving wideband electrical transparency (symmetric case) and wideband impedance transformation (bianisotropic case) with these Huygens’ metasurface unit cells. Moreover, it is shown that these expressions can be realized with transmission-line stubs. These expressions are then used to design subwavelength thin Huygens’ metasurfaces immersed in an air gap between two dielectric media. It is shown, through full-wave simulations, that wideband electrical transparency and impedance transformation are realized for a normally impinging plane wave.
Hideo Kasami - One of the best experts on this subject based on the ideXlab platform.
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bonding Wire Loop antenna in standard ball grid array package for 60 ghz short range Wireless communication
IEEE Transactions on Antennas and Propagation, 2013Co-Authors: Yukako Tsutsumi, Hiroki Shoki, Takayoshi Ito, Koh Hashimoto, Shuichi Obayashi, Hideo KasamiAbstract:High-speed short-range Wireless communication systems are expected to utilize the 60-GHz band. This paper presents a bonding Wire Loop antenna in a standard ball grid array (BGA) package for 60-GHz short-range Wireless communication. The proposed antenna has a Loop shape and consists of two bonding Wires connecting to a complementary metal–oxide–semiconductor (CMOS) chip and a metal plate on an interposer in a BGA package. The antenna can be fabricated at low cost by a conventional BGA package fabrication process. The BGA package is mounted on a printed circuit board (PCB) that consists of resin substrate, such as FR-4. The broadband impedance characteristic is achieved by adjusting the position of the metal pad for Wire bonding. The antenna gain is improved by forming cranked ledges and notches in the metal patterns of the PCB, and the wide-angle radiation characteristic is realized. The sizes of the fabricated antenna and BGA package are approximately 0.6 mm $\,\times \,$ 1.0 mm $\,\times \,$ 0.3 mm and 9.0 mm $\,\times \,$ 9.0 mm $\,\times \,$ 0.9 mm, respectively. Performing measurements, the antenna gain with the PCB is from $-$ 2.4 to 4.9 dBi over the 57- to 65-GHz frequency range and over an angular range of 60 $^\circ$ in the horizontal plane.
Christoph A Binkert - One of the best experts on this subject based on the ideXlab platform.
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Loop snare technique for difficult inferior vena cava filter retrievals
Journal of Vascular and Interventional Radiology, 2007Co-Authors: Lisa Rubenstein, Albert K Chun, Megan Chew, Christoph A BinkertAbstract:Retrievable inferior vena cava (IVC) filters are generally retrieved without difficulties. However, when filters are tilted against the IVC wall, engaging the tip or hook of the filter can be difficult with the use of standard techniques. This report describes an alternative method of successful IVC filter retrieval by creating a Wire Loop between the filter legs, including the tip of the filter. This Loop snare was successfully applied in eight cases after filter retrieval failed with the Recovery Cone or simple snare technique.
Yukako Tsutsumi - One of the best experts on this subject based on the ideXlab platform.
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bonding Wire Loop antenna in standard ball grid array package for 60 ghz short range Wireless communication
IEEE Transactions on Antennas and Propagation, 2013Co-Authors: Yukako Tsutsumi, Hiroki Shoki, Takayoshi Ito, Koh Hashimoto, Shuichi Obayashi, Hideo KasamiAbstract:High-speed short-range Wireless communication systems are expected to utilize the 60-GHz band. This paper presents a bonding Wire Loop antenna in a standard ball grid array (BGA) package for 60-GHz short-range Wireless communication. The proposed antenna has a Loop shape and consists of two bonding Wires connecting to a complementary metal–oxide–semiconductor (CMOS) chip and a metal plate on an interposer in a BGA package. The antenna can be fabricated at low cost by a conventional BGA package fabrication process. The BGA package is mounted on a printed circuit board (PCB) that consists of resin substrate, such as FR-4. The broadband impedance characteristic is achieved by adjusting the position of the metal pad for Wire bonding. The antenna gain is improved by forming cranked ledges and notches in the metal patterns of the PCB, and the wide-angle radiation characteristic is realized. The sizes of the fabricated antenna and BGA package are approximately 0.6 mm $\,\times \,$ 1.0 mm $\,\times \,$ 0.3 mm and 9.0 mm $\,\times \,$ 9.0 mm $\,\times \,$ 0.9 mm, respectively. Performing measurements, the antenna gain with the PCB is from $-$ 2.4 to 4.9 dBi over the 57- to 65-GHz frequency range and over an angular range of 60 $^\circ$ in the horizontal plane.
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bonding Wire Loop antenna built into standard bga package for 60 ghz short range Wireless communication
International Microwave Symposium, 2011Co-Authors: Yukako Tsutsumi, Hiroki Shoki, Shuichi Obayashi, Tasuku MorookaAbstract:The unlicensed 60 GHz frequency band is suitable for high-speed Wireless systems with transmission rates of 1 Gbps or more. In this paper, we propose a bonding Wire antenna built into a BGA package for 60 GHz short-range Wireless communication. This antenna utilizes two bonding Wires and a metal plate on an interposer in a BGA package and has a Loop shape. The proposed antenna is built into a standard BGA package without special modification, so that it can be fabricated at low cost by conventional BGA package fabrication process. The first and unique evaluation of the antenna fully sealed by encapsulation resin was done by measurement. We describe the operation mechanism of the proposed antenna, the design procedure and the measurement results.
