The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Wei Hong - One of the best experts on this subject based on the ideXlab platform.
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Single-Beam 1-Bit Reflective Metasurface Using Pre-Phased Unit Cells for Normally Incident Plane Waves
2020Co-Authors: Jiexi Yin, Qun Lou, Haiming Wang, Zhi Ning Chen, Wei HongAbstract:<p>A single-beam pre-phased 1-bit reflective metasurface is proposed to achieve single-beam patterns under normally Incident Plane waves. Theoretical analysis and numerical simulations are presented to show that, under normally Incident waves, single-beam patterns can be achieved by introducing a fixed pre-phase distribution with two values in the 1-bit metasurface. Compared with conventional 1-bit reflective metasurfaces, the proposed scheme alleviates the inherent limitation of single-beam patterns on 1-bit reflective metasurfaces under normally Incident Plane waves. To verify the proposed scheme, a 1-bit unit cell is designed with a 180º ± 25º phase difference between the two states for frequencies ranging from 34.3 to 49.9 GHz, and a layer-stacking method is proposed to achieve two pre-phases with a 90-degree phase difference. As an example, three 1-bit reflective metasurfaces comprising 20×20 unit cells with single beams pointing separately at 0, 15 and 30 degrees are designed and measured over frequencies of 37.0 to 41.0 GHz; the measured sidelobe levels are less than -7.8 dB. Simulated and measured results show that the proposed pre-phased 1-bit metasurface can achieve single-beam patterns under normally Incident Plane waves.</p>
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Single-Beam 1 Bit Reflective Metasurface Using Prephased Unit Cells for Normally Incident Plane Waves
IEEE Transactions on Antennas and Propagation, 2020Co-Authors: Jiexi Yin, Qun Lou, Haiming Wang, Zhi Ning Chen, Wei HongAbstract:A single-beam prephased 1 bit reflective metasurface is proposed to achieve single-beam patterns under normally Incident Plane waves. Theoretical analysis and numerical simulations are presented to show that, under normally Incident waves, single-beam patterns can be achieved by introducing a fixed prephase distribution with two values in the 1 bit metasurface. Compared with conventional 1 bit reflective metasurfaces, the proposed scheme alleviates the inherent limitation of single-beam patterns on 1 bit reflective metasurfaces under normally Incident Plane waves. To verify the proposed scheme, a 1 bit unit cell is designed with a $180^\circ \pm 25^\circ $ phase difference between the two states for frequencies ranging from 34.3 to 49.9 GHz, and a layer-stacking method is proposed to achieve two prephases with a 90° phase difference. As an example, three 1 bit reflective metasurfaces comprising 20 × 20 unit cells with single beams pointing separately at 0°, 15°, and 30° are designed and measured over frequencies of 37.0 to 41.0 GHz; the measured sidelobe levels are less than −7.8 dB. Simulated and measured results show that the proposed prephased 1 bit metasurface can achieve single-beam patterns under normally Incident Plane waves.
Ning Yan Zhu - One of the best experts on this subject based on the ideXlab platform.
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diffraction of a skewly Incident Plane wave by an anisotropic impedance wedge a class of exactly solvable cases
Wave Motion, 1999Co-Authors: Mikhail A. Lyalinov, Ning Yan ZhuAbstract:Abstract The Sommerfeld–Malyuzhinets’ technique and the special function χΦ, which is originally introduced in the study of wave diffraction by a wedge located in a gyroelectric medium, have been used to find the exact solution for diffraction of a skewly Incident and arbitrarily polarized Plane wave by wedges with an arbitrary opening angle and with a class of specific, but in general non-axial anisotropic face impedances. Just for these impedance faces suitable linear combinations of the field components parallel to the edge of the wedge are no longer completely related to each other on the wedge surfaces; an application of the Sommerfeld–Malyuzhinets’ technique to these boundary conditions then leads to inhomogeneous difference equations for the spectral functions; in terms of the χΦ function these functional equations are transformed to such simple forms that their closed-form exact solutions are given immediately. The uniform asymptotic expansion is then obtained via the method of saddle point. This solution coincides with exact solutions for tensor impedance wedges illuminated by a normally Incident Plane wave and agrees very well with both analytical perturbation solution as well as numerical results of the method of parabolic equation for a skewly Incident Plane wave. Typical diffraction behavior dependent on the skewness of the Incident wave is also shown.
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Diffraction of a normally Incident Plane wave at a wedge with identical tensor impedance faces
IEEE Transactions on Antennas and Propagation, 1999Co-Authors: Mikhail A. Lyalinov, Ning Yan ZhuAbstract:Diffraction of a normally Incident Plane wave by a wedge with identical tensor impedance faces is studied and an exact solution is obtained by reducing the original problem to two decoupled and already solved ones. A uniform asymptotic solution then follows from the exact one and agrees excellently with numerical results due to the method of parabolic equation.
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Diffraction of a skewly Incident Plane wave by an anisotropic impedance wedge – a class of exactly solvable cases
Wave Motion, 1999Co-Authors: Mikhail A. Lyalinov, Ning Yan ZhuAbstract:Abstract The Sommerfeld–Malyuzhinets’ technique and the special function χΦ, which is originally introduced in the study of wave diffraction by a wedge located in a gyroelectric medium, have been used to find the exact solution for diffraction of a skewly Incident and arbitrarily polarized Plane wave by wedges with an arbitrary opening angle and with a class of specific, but in general non-axial anisotropic face impedances. Just for these impedance faces suitable linear combinations of the field components parallel to the edge of the wedge are no longer completely related to each other on the wedge surfaces; an application of the Sommerfeld–Malyuzhinets’ technique to these boundary conditions then leads to inhomogeneous difference equations for the spectral functions; in terms of the χΦ function these functional equations are transformed to such simple forms that their closed-form exact solutions are given immediately. The uniform asymptotic expansion is then obtained via the method of saddle point. This solution coincides with exact solutions for tensor impedance wedges illuminated by a normally Incident Plane wave and agrees very well with both analytical perturbation solution as well as numerical results of the method of parabolic equation for a skewly Incident Plane wave. Typical diffraction behavior dependent on the skewness of the Incident wave is also shown.
Jiexi Yin - One of the best experts on this subject based on the ideXlab platform.
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Single-Beam 1-Bit Reflective Metasurface Using Pre-Phased Unit Cells for Normally Incident Plane Waves
2020Co-Authors: Jiexi Yin, Qun Lou, Haiming Wang, Zhi Ning Chen, Wei HongAbstract:<p>A single-beam pre-phased 1-bit reflective metasurface is proposed to achieve single-beam patterns under normally Incident Plane waves. Theoretical analysis and numerical simulations are presented to show that, under normally Incident waves, single-beam patterns can be achieved by introducing a fixed pre-phase distribution with two values in the 1-bit metasurface. Compared with conventional 1-bit reflective metasurfaces, the proposed scheme alleviates the inherent limitation of single-beam patterns on 1-bit reflective metasurfaces under normally Incident Plane waves. To verify the proposed scheme, a 1-bit unit cell is designed with a 180º ± 25º phase difference between the two states for frequencies ranging from 34.3 to 49.9 GHz, and a layer-stacking method is proposed to achieve two pre-phases with a 90-degree phase difference. As an example, three 1-bit reflective metasurfaces comprising 20×20 unit cells with single beams pointing separately at 0, 15 and 30 degrees are designed and measured over frequencies of 37.0 to 41.0 GHz; the measured sidelobe levels are less than -7.8 dB. Simulated and measured results show that the proposed pre-phased 1-bit metasurface can achieve single-beam patterns under normally Incident Plane waves.</p>
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Single-Beam 1 Bit Reflective Metasurface Using Prephased Unit Cells for Normally Incident Plane Waves
IEEE Transactions on Antennas and Propagation, 2020Co-Authors: Jiexi Yin, Qun Lou, Haiming Wang, Zhi Ning Chen, Wei HongAbstract:A single-beam prephased 1 bit reflective metasurface is proposed to achieve single-beam patterns under normally Incident Plane waves. Theoretical analysis and numerical simulations are presented to show that, under normally Incident waves, single-beam patterns can be achieved by introducing a fixed prephase distribution with two values in the 1 bit metasurface. Compared with conventional 1 bit reflective metasurfaces, the proposed scheme alleviates the inherent limitation of single-beam patterns on 1 bit reflective metasurfaces under normally Incident Plane waves. To verify the proposed scheme, a 1 bit unit cell is designed with a $180^\circ \pm 25^\circ $ phase difference between the two states for frequencies ranging from 34.3 to 49.9 GHz, and a layer-stacking method is proposed to achieve two prephases with a 90° phase difference. As an example, three 1 bit reflective metasurfaces comprising 20 × 20 unit cells with single beams pointing separately at 0°, 15°, and 30° are designed and measured over frequencies of 37.0 to 41.0 GHz; the measured sidelobe levels are less than −7.8 dB. Simulated and measured results show that the proposed prephased 1 bit metasurface can achieve single-beam patterns under normally Incident Plane waves.
Ji Xiaodon - One of the best experts on this subject based on the ideXlab platform.
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Dynamic stress concentration of an underground cylindrical lined cavity subjected to Incident Plane SH waves(I) :3-D series solution
World Earthquake Engineering, 2013Co-Authors: Ji XiaodonAbstract:By using series expansion method,dynamic stress concentration of an underground cylindrical lined cavity subjected to Incident Plane SH waves was studied and the three-dimensional series solution is presented. When the angle included between Incident Plane and cavity's section Plane closes to zero,the result is reduced to two-dimensional series solution. The three-dimensional series solution provides a theoretical foundation for further quantitative analyisis of dynamic stress concentration of the lined cavity subjected to Incident Plane SH waves.
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Scattering of an underground cylindrical lined cavity subjected to Incident Plane SH waves(I): 3-D series solution
Journal of Liaoning Technical University, 2013Co-Authors: Ji XiaodonAbstract:By using series expansion method, scattering of a underground cylindrical lined cavity subjected to Incident Plane SH waves was studied and the 3-D series solution was presented. The results of study show that when the Plane of Incident waves and z-axis of the cavity are perpendicular to one another, the series solution can be reduced to the solution for the cavity in two-dimensional half-space. The series solution can be used to quantitatively analyze the effects of a cylindrical lined cavity subjected to Incident SH waves due to varies Incident wavelength and angle on the ground motion.
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Dynamic stress concentration of an underground cylindrical lined cavity subjected to Incident Plane SH waves(II) : numerical results
World Earthquake Engineering, 2013Co-Authors: Ji XiaodonAbstract:The series solution of an underground cylindrical lined cavity subjected to Incident Plane SH waves was used to quantitatively analyze the effect of Incident wavelength,Incident angle,diameter of the cavity,and liner stiffness on dynamic stress concentration factor. The numerical results show that:( 1) the rigidity of liner has great effect on dynamic stress concentration factor,the factor is highest for a cavity with rigid lining,and it takes second place for an unlined cavity,and it is lowest for a cavity with flexible lining; the dynamic hoop and axial stress concentration factor can be 83. 49 and 85. 31;( 2) the frequency and the angles of the Incident waves also plays an important role in the dynamic stress concentration factor.
Mikhail A. Lyalinov - One of the best experts on this subject based on the ideXlab platform.
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diffraction of a skewly Incident Plane wave by an anisotropic impedance wedge a class of exactly solvable cases
Wave Motion, 1999Co-Authors: Mikhail A. Lyalinov, Ning Yan ZhuAbstract:Abstract The Sommerfeld–Malyuzhinets’ technique and the special function χΦ, which is originally introduced in the study of wave diffraction by a wedge located in a gyroelectric medium, have been used to find the exact solution for diffraction of a skewly Incident and arbitrarily polarized Plane wave by wedges with an arbitrary opening angle and with a class of specific, but in general non-axial anisotropic face impedances. Just for these impedance faces suitable linear combinations of the field components parallel to the edge of the wedge are no longer completely related to each other on the wedge surfaces; an application of the Sommerfeld–Malyuzhinets’ technique to these boundary conditions then leads to inhomogeneous difference equations for the spectral functions; in terms of the χΦ function these functional equations are transformed to such simple forms that their closed-form exact solutions are given immediately. The uniform asymptotic expansion is then obtained via the method of saddle point. This solution coincides with exact solutions for tensor impedance wedges illuminated by a normally Incident Plane wave and agrees very well with both analytical perturbation solution as well as numerical results of the method of parabolic equation for a skewly Incident Plane wave. Typical diffraction behavior dependent on the skewness of the Incident wave is also shown.
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Diffraction of a normally Incident Plane wave at a wedge with identical tensor impedance faces
IEEE Transactions on Antennas and Propagation, 1999Co-Authors: Mikhail A. Lyalinov, Ning Yan ZhuAbstract:Diffraction of a normally Incident Plane wave by a wedge with identical tensor impedance faces is studied and an exact solution is obtained by reducing the original problem to two decoupled and already solved ones. A uniform asymptotic solution then follows from the exact one and agrees excellently with numerical results due to the method of parabolic equation.
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Diffraction of a skewly Incident Plane wave by an anisotropic impedance wedge – a class of exactly solvable cases
Wave Motion, 1999Co-Authors: Mikhail A. Lyalinov, Ning Yan ZhuAbstract:Abstract The Sommerfeld–Malyuzhinets’ technique and the special function χΦ, which is originally introduced in the study of wave diffraction by a wedge located in a gyroelectric medium, have been used to find the exact solution for diffraction of a skewly Incident and arbitrarily polarized Plane wave by wedges with an arbitrary opening angle and with a class of specific, but in general non-axial anisotropic face impedances. Just for these impedance faces suitable linear combinations of the field components parallel to the edge of the wedge are no longer completely related to each other on the wedge surfaces; an application of the Sommerfeld–Malyuzhinets’ technique to these boundary conditions then leads to inhomogeneous difference equations for the spectral functions; in terms of the χΦ function these functional equations are transformed to such simple forms that their closed-form exact solutions are given immediately. The uniform asymptotic expansion is then obtained via the method of saddle point. This solution coincides with exact solutions for tensor impedance wedges illuminated by a normally Incident Plane wave and agrees very well with both analytical perturbation solution as well as numerical results of the method of parabolic equation for a skewly Incident Plane wave. Typical diffraction behavior dependent on the skewness of the Incident wave is also shown.
