The Experts below are selected from a list of 3990 Experts worldwide ranked by ideXlab platform
Erik Lier - One of the best experts on this subject based on the ideXlab platform.
-
inhomogeneous metasurfaces with engineered dispersion for broadband hybrid mode Horn Antennas
IEEE Transactions on Antennas and Propagation, 2013Co-Authors: Qi Wu, Clinton P. Scarborough, Erik Lier, Douglas H Werner, R K ShawAbstract:Metamaterial and metasurface structures, which satisfy the balanced hybrid conditions, have been recently proposed for designing hybrid-mode soft and hard Horn Antennas. In this paper, we present the design of broadband soft metasurfaces and their applications in hybrid-mode conical Horns. These designs exhibit surface characteristics that can be controlled by adjusting the constituent structural elements. The analysis and design of metasurfaces were performed on both a planar platform and in a cylindrical waveguide structure. Such dispersion-engineered metasurfaces with customized surface properties can support the desired hybrid modes in a cylindrical waveguide, facilitating their usage in Horn Antennas. By engineering the metasurfaces with regard to their surface impedance as well as tailoring their spatial distributions along the wall of the Horn, we demonstrate an inhomogeneous metaHorn with superior performance and broader bandwidth compared to those with uniform liners. The symmetric far-field radiation patterns with low sidelobe and cross-polarization levels, together with the corresponding aperture field distributions, signifies the hybrid-mode operation of the Horn, validating the efficacy and broadband performance of the metasurfaces. Such metasurface-lined Horns can be employed as soft feeds in dual polarization antenna systems.
-
Design synthesis of metasurfaces for broadband hybrid-mode Horn Antennas with enhanced radiation pattern and polarization characteristics
IEEE Transactions on Antennas and Propagation, 2012Co-Authors: Qi Wu, Clinton P. Scarborough, Erik Lier, Douglas H Werner, Xiande WangAbstract:Metamaterial surfaces (metasurfaces) with a low effective index of refraction have been recently proposed for application in the design of hybrid-mode Horn Antennas, such as soft and hard Horns. Here we explore designs of several metasurfaces and their use as liners for coating the interior walls of Horn Antennas. The design process combines the genetic algorithm optimization technique with a full-wave electromagnetic solver to create dispersion-engineered metamaterials that possess customized surface impedance properties. A metamaterial parameter extraction technique is developed and employed in the optimization process, which is based on the surface impedance expressions for a homogeneous slab backed by a perfectly conducting ground plane illuminated at near grazing incidence. The optimized meta-surface is found to be equivalent to a low index metamaterial with a dispersion that can improve the performance of conventional Horn Antennas over the entire K-u-band while introducing negligible losses. We conclude with a numerical study of a conical Horn antenna whose interior is lined with a low index metasurface. The far-field radiation patterns and aperture field distributions confirm hybrid-mode operation over a wide bandwidth, validating the proposed metasurface design methodology.
-
review of soft and hard Horn Antennas including metamaterial based hybrid mode Horns
IEEE Antennas and Propagation Magazine, 2010Co-Authors: Erik LierAbstract:This paper is divided into three parts. Part one gives an overview of the early history of the design and implementation of hard Horn Antennas, and of the concept formulation of soft and hard electromagnetic surfaces. Part two presents a review of all known classes of soft and hard hybrid-mode Horns. Part three presents a new class of hybrid-mode Horns, based on the use of a low-index metamaterial liner on the wall. Moment-Method analysis of both soft and hard metamaterial Horns indicates that it may be feasible to realize these Horns with very large bandwidth. This is because the desired (analyzed) metamaterial dispersion is similar to the Drude dispersion curve (monotonically increasing permittivity as a function of frequency), which represents typical electromagnetic dispersion in dense media. A successful implementation of these Horns depends on whether low-index metamaterials can be implemented with polarization-independent boundary impedance, favorable dispersion characteristics, and reasonable loss, mass, and production cost.
-
metamaterial hybrid mode Horn Antennas
IEEE Antennas and Propagation Society International Symposium, 2009Co-Authors: Erik Lier, R K ShawAbstract:It was shown by moment method analysis that soft and hard metamaterial Horns offer broadband performance if a metamaterial with the required dispersion can be implemented. It was also shown that the required dispersion curve is monotonically increasing similar to the Drude dispersion, strongly indicating that these Horns can be realized. In two accompanying papers the design and analysis of a hexagonal hard metamaterial Horn for a multi-beam reflector antenna is presented [8, 9].
R K Shaw - One of the best experts on this subject based on the ideXlab platform.
-
inhomogeneous metasurfaces with engineered dispersion for broadband hybrid mode Horn Antennas
IEEE Transactions on Antennas and Propagation, 2013Co-Authors: Qi Wu, Clinton P. Scarborough, Erik Lier, Douglas H Werner, R K ShawAbstract:Metamaterial and metasurface structures, which satisfy the balanced hybrid conditions, have been recently proposed for designing hybrid-mode soft and hard Horn Antennas. In this paper, we present the design of broadband soft metasurfaces and their applications in hybrid-mode conical Horns. These designs exhibit surface characteristics that can be controlled by adjusting the constituent structural elements. The analysis and design of metasurfaces were performed on both a planar platform and in a cylindrical waveguide structure. Such dispersion-engineered metasurfaces with customized surface properties can support the desired hybrid modes in a cylindrical waveguide, facilitating their usage in Horn Antennas. By engineering the metasurfaces with regard to their surface impedance as well as tailoring their spatial distributions along the wall of the Horn, we demonstrate an inhomogeneous metaHorn with superior performance and broader bandwidth compared to those with uniform liners. The symmetric far-field radiation patterns with low sidelobe and cross-polarization levels, together with the corresponding aperture field distributions, signifies the hybrid-mode operation of the Horn, validating the efficacy and broadband performance of the metasurfaces. Such metasurface-lined Horns can be employed as soft feeds in dual polarization antenna systems.
-
metamaterial hybrid mode Horn Antennas
IEEE Antennas and Propagation Society International Symposium, 2009Co-Authors: Erik Lier, R K ShawAbstract:It was shown by moment method analysis that soft and hard metamaterial Horns offer broadband performance if a metamaterial with the required dispersion can be implemented. It was also shown that the required dispersion curve is monotonically increasing similar to the Drude dispersion, strongly indicating that these Horns can be realized. In two accompanying papers the design and analysis of a hexagonal hard metamaterial Horn for a multi-beam reflector antenna is presented [8, 9].
-
design and simulation of metamaterial based hybrid mode Horn Antennas
Electronics Letters, 2008Co-Authors: E Lier, R K ShawAbstract:The design and analysis of novel hybrid-mode soft and hard Horn Antennas with a low index metamaterial wall liner are presented. Metamaterial Horn Antennas have the potential for considerably larger bandwidth than the current state-of-the-art Horns. The optimal or required metamaterial dispersion curve for these Horns is qualitatively similar to the Drude dispersion, which indicates that the metamaterial Horns are realisable.
Qi Wu - One of the best experts on this subject based on the ideXlab platform.
-
inhomogeneous metasurfaces with engineered dispersion for broadband hybrid mode Horn Antennas
IEEE Transactions on Antennas and Propagation, 2013Co-Authors: Qi Wu, Clinton P. Scarborough, Erik Lier, Douglas H Werner, R K ShawAbstract:Metamaterial and metasurface structures, which satisfy the balanced hybrid conditions, have been recently proposed for designing hybrid-mode soft and hard Horn Antennas. In this paper, we present the design of broadband soft metasurfaces and their applications in hybrid-mode conical Horns. These designs exhibit surface characteristics that can be controlled by adjusting the constituent structural elements. The analysis and design of metasurfaces were performed on both a planar platform and in a cylindrical waveguide structure. Such dispersion-engineered metasurfaces with customized surface properties can support the desired hybrid modes in a cylindrical waveguide, facilitating their usage in Horn Antennas. By engineering the metasurfaces with regard to their surface impedance as well as tailoring their spatial distributions along the wall of the Horn, we demonstrate an inhomogeneous metaHorn with superior performance and broader bandwidth compared to those with uniform liners. The symmetric far-field radiation patterns with low sidelobe and cross-polarization levels, together with the corresponding aperture field distributions, signifies the hybrid-mode operation of the Horn, validating the efficacy and broadband performance of the metasurfaces. Such metasurface-lined Horns can be employed as soft feeds in dual polarization antenna systems.
-
Design synthesis of metasurfaces for broadband hybrid-mode Horn Antennas with enhanced radiation pattern and polarization characteristics
IEEE Transactions on Antennas and Propagation, 2012Co-Authors: Qi Wu, Clinton P. Scarborough, Erik Lier, Douglas H Werner, Xiande WangAbstract:Metamaterial surfaces (metasurfaces) with a low effective index of refraction have been recently proposed for application in the design of hybrid-mode Horn Antennas, such as soft and hard Horns. Here we explore designs of several metasurfaces and their use as liners for coating the interior walls of Horn Antennas. The design process combines the genetic algorithm optimization technique with a full-wave electromagnetic solver to create dispersion-engineered metamaterials that possess customized surface impedance properties. A metamaterial parameter extraction technique is developed and employed in the optimization process, which is based on the surface impedance expressions for a homogeneous slab backed by a perfectly conducting ground plane illuminated at near grazing incidence. The optimized meta-surface is found to be equivalent to a low index metamaterial with a dispersion that can improve the performance of conventional Horn Antennas over the entire K-u-band while introducing negligible losses. We conclude with a numerical study of a conical Horn antenna whose interior is lined with a low index metasurface. The far-field radiation patterns and aperture field distributions confirm hybrid-mode operation over a wide bandwidth, validating the proposed metasurface design methodology.
Clinton P. Scarborough - One of the best experts on this subject based on the ideXlab platform.
-
inhomogeneous metasurfaces with engineered dispersion for broadband hybrid mode Horn Antennas
IEEE Transactions on Antennas and Propagation, 2013Co-Authors: Qi Wu, Clinton P. Scarborough, Erik Lier, Douglas H Werner, R K ShawAbstract:Metamaterial and metasurface structures, which satisfy the balanced hybrid conditions, have been recently proposed for designing hybrid-mode soft and hard Horn Antennas. In this paper, we present the design of broadband soft metasurfaces and their applications in hybrid-mode conical Horns. These designs exhibit surface characteristics that can be controlled by adjusting the constituent structural elements. The analysis and design of metasurfaces were performed on both a planar platform and in a cylindrical waveguide structure. Such dispersion-engineered metasurfaces with customized surface properties can support the desired hybrid modes in a cylindrical waveguide, facilitating their usage in Horn Antennas. By engineering the metasurfaces with regard to their surface impedance as well as tailoring their spatial distributions along the wall of the Horn, we demonstrate an inhomogeneous metaHorn with superior performance and broader bandwidth compared to those with uniform liners. The symmetric far-field radiation patterns with low sidelobe and cross-polarization levels, together with the corresponding aperture field distributions, signifies the hybrid-mode operation of the Horn, validating the efficacy and broadband performance of the metasurfaces. Such metasurface-lined Horns can be employed as soft feeds in dual polarization antenna systems.
-
Design synthesis of metasurfaces for broadband hybrid-mode Horn Antennas with enhanced radiation pattern and polarization characteristics
IEEE Transactions on Antennas and Propagation, 2012Co-Authors: Qi Wu, Clinton P. Scarborough, Erik Lier, Douglas H Werner, Xiande WangAbstract:Metamaterial surfaces (metasurfaces) with a low effective index of refraction have been recently proposed for application in the design of hybrid-mode Horn Antennas, such as soft and hard Horns. Here we explore designs of several metasurfaces and their use as liners for coating the interior walls of Horn Antennas. The design process combines the genetic algorithm optimization technique with a full-wave electromagnetic solver to create dispersion-engineered metamaterials that possess customized surface impedance properties. A metamaterial parameter extraction technique is developed and employed in the optimization process, which is based on the surface impedance expressions for a homogeneous slab backed by a perfectly conducting ground plane illuminated at near grazing incidence. The optimized meta-surface is found to be equivalent to a low index metamaterial with a dispersion that can improve the performance of conventional Horn Antennas over the entire K-u-band while introducing negligible losses. We conclude with a numerical study of a conical Horn antenna whose interior is lined with a low index metasurface. The far-field radiation patterns and aperture field distributions confirm hybrid-mode operation over a wide bandwidth, validating the proposed metasurface design methodology.
Douglas H Werner - One of the best experts on this subject based on the ideXlab platform.
-
inhomogeneous metasurfaces with engineered dispersion for broadband hybrid mode Horn Antennas
IEEE Transactions on Antennas and Propagation, 2013Co-Authors: Qi Wu, Clinton P. Scarborough, Erik Lier, Douglas H Werner, R K ShawAbstract:Metamaterial and metasurface structures, which satisfy the balanced hybrid conditions, have been recently proposed for designing hybrid-mode soft and hard Horn Antennas. In this paper, we present the design of broadband soft metasurfaces and their applications in hybrid-mode conical Horns. These designs exhibit surface characteristics that can be controlled by adjusting the constituent structural elements. The analysis and design of metasurfaces were performed on both a planar platform and in a cylindrical waveguide structure. Such dispersion-engineered metasurfaces with customized surface properties can support the desired hybrid modes in a cylindrical waveguide, facilitating their usage in Horn Antennas. By engineering the metasurfaces with regard to their surface impedance as well as tailoring their spatial distributions along the wall of the Horn, we demonstrate an inhomogeneous metaHorn with superior performance and broader bandwidth compared to those with uniform liners. The symmetric far-field radiation patterns with low sidelobe and cross-polarization levels, together with the corresponding aperture field distributions, signifies the hybrid-mode operation of the Horn, validating the efficacy and broadband performance of the metasurfaces. Such metasurface-lined Horns can be employed as soft feeds in dual polarization antenna systems.
-
Design synthesis of metasurfaces for broadband hybrid-mode Horn Antennas with enhanced radiation pattern and polarization characteristics
IEEE Transactions on Antennas and Propagation, 2012Co-Authors: Qi Wu, Clinton P. Scarborough, Erik Lier, Douglas H Werner, Xiande WangAbstract:Metamaterial surfaces (metasurfaces) with a low effective index of refraction have been recently proposed for application in the design of hybrid-mode Horn Antennas, such as soft and hard Horns. Here we explore designs of several metasurfaces and their use as liners for coating the interior walls of Horn Antennas. The design process combines the genetic algorithm optimization technique with a full-wave electromagnetic solver to create dispersion-engineered metamaterials that possess customized surface impedance properties. A metamaterial parameter extraction technique is developed and employed in the optimization process, which is based on the surface impedance expressions for a homogeneous slab backed by a perfectly conducting ground plane illuminated at near grazing incidence. The optimized meta-surface is found to be equivalent to a low index metamaterial with a dispersion that can improve the performance of conventional Horn Antennas over the entire K-u-band while introducing negligible losses. We conclude with a numerical study of a conical Horn antenna whose interior is lined with a low index metasurface. The far-field radiation patterns and aperture field distributions confirm hybrid-mode operation over a wide bandwidth, validating the proposed metasurface design methodology.