Sergei Tretyakov - Academia.edu (original) (raw)
Nonlinearities, Activity and Computational by Sergei Tretyakov
New Journal of Physics, 2021
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Papers by Sergei Tretyakov
We propose to use an antenna composed of two orthogonal helices as a low-scattering sensor. The v... more We propose to use an antenna composed of two orthogonal helices as a low-scattering sensor. The vector effective length is derived for the antenna using the small dipole approximation for the helices. The antenna can transmit and receive circular polarization in all directions with the Huygens' pattern. We observe that the antenna geometry does not backscatter, regardless of the polarization, when the incidence direction is normal to the plane of the helices. Scattered fields, scattered axial ratio, and the scattering cross section are presented. We show that the zero-backscattering property holds also for the antenna when it is capable to receive all the available power with conjugate loading. The approximate analytical model is validated with full-wave simulations.
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We consider resonant patch antennas, implemented using loaded transmission-line networks and othe... more We consider resonant patch antennas, implemented using loaded transmission-line networks and other exotic structures having engineered dispersion. An analytical expression is derived for the ratio of radiation quality factors of such antennas and conventional patch antennas loaded with (reference) dielectrics. In the ideal case this ratio depends only on the propagation constant and wave impedance of the structure under test, and it can be conveniently used to study what kind of dispersion leads to improved impedance bandwidth. We illustrate the effect of dispersion by implementing a resonant patch antenna using a periodic network of LC elements. The analytical results predicting enhanced impedance bandwidth compared to the reference results are validated using a commercial circuit simulator. Discussion is conducted on the practical limitations for the use of the proposed expression.
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Ieee Transactions on Antennas and Propagation, Oct 1, 2009
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Journal of Electromagnetic Waves and Applications, 2003
... Abstract|New artifi cial reactive impedance surfaces have been re-cently suggested by Sievenp... more ... Abstract|New artifi cial reactive impedance surfaces have been re-cently suggested by Sievenpiper et al. ... 1. These novel artifi cial layers are also called 2D photonic (or electromagnetic, which is more appropriate for the frequency band of applications) bandgap structures. ...
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Physical Review B Condensed Matter and Materials Physics, 2007
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Physics Letters a, Apr 7, 2008
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Unknown, Jun 1, 1989
ABSTRACT
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IEE Proceedings H Microwaves, Antennas and Propagation, 1991
The paper explores reflection and transmission characteristics of single and multilayer chiral sl... more The paper explores reflection and transmission characteristics of single and multilayer chiral slabs. The analysis is based on vector circuit modelling of chiral slabs in terms of transverse fields, dyadic impedance, admittance or transmission matrix components. Reflection and transmission coefficients for arbitrary angles of incidence and arbitrary polarisation states of the fields are derived. From these coefficients and to exemplify the method, reflected and transmitted fields of the co- and cross-polarised waves are calculated in single and multilayer chiral slabs for various electromagnetic and geometrical parameter values.
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Eprint Arxiv Physics 0504123, Apr 18, 2005
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Abstract In this paper, two homogenization models are presented for the analysis of mushroom stru... more Abstract In this paper, two homogenization models are presented for the analysis of mushroom structures. The differences of these models rise from the different way of modeling the array of metallic vias connecting the metallic patches to the ground plane. It is shown that for electrically thin mushroom structures the results of these models concur with each other. Furthermore, it is shown in this paper that the use of metallic vias in mushroom structures results in additional resonances for the TM-polarized incident fields.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Nasa Sti Recon Technical Report N, Apr 1, 1989
The Silberstein wave-field decomposition of electromagnetic fields is applied to the problem of w... more The Silberstein wave-field decomposition of electromagnetic fields is applied to the problem of wave propagation in chiral medium. The problem involving a planar interface between two chiral media is considered and eigensolutions for the reflection and transmission problems are given. Numerical results are calculated for the eigenpolarizations and reflection coefficients with different incident field polarizations, for the problem involving an interface between isotropic and chiral media. Also, the limit cases of reflection from a half space with only small amount of chirality are studied and it is shown that the chirality gives a second-order effect on the co-polarized reflection coefficient and a first-order effect on cross-polarization.
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Nasa Sti Recon Technical Report N, Dec 1, 1990
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Cloaking using a volumetric structure composed of stacked two-dimensional transmission-line netwo... more Cloaking using a volumetric structure composed of stacked two-dimensional transmission-line networks is verified with measurements. The measurements are done in a waveguide, in which an array of metallic cylinders is inserted causing a short-circuit in the waveguide. The metal cylinders are cloaked using a previously designed and simulated cloak that hides the cylinders and thus enables wave propagation inside the waveguide.
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Journal of Electromagnetic Waves and Applications, Apr 3, 2012
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Proceedings of the 5th European Conference on Antennas and Propagation, Apr 11, 2011
ABSTRACT Electromagnetic cloaks based on volumetric transmission-line networks have been previous... more ABSTRACT Electromagnetic cloaks based on volumetric transmission-line networks have been previously proposed as candidates for simple, cheap, and broadband cloaking devices that can be used to hide mesh-like structures. In this paper we demonstrate, with numerical simulations, how a metallic object placed in the near-field of a horn antenna can be made “invisible” with such a cloak, thus restoring the antenna's radiation properties to resemble the case when the antenna is alone in free space.
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2013 International Symposium on Electromagnetic Theory, 2013
ABSTRACT We study the occurrence of the so-called antiresonance in the material parameters (permi... more ABSTRACT We study the occurrence of the so-called antiresonance in the material parameters (permittivity, permeability) characterizing the electromagnetic response of a composite material slab. The material parameters are retrieved using the wellknown reflection/transmission method. As many previous works have either claimed or assumed that the antiresonance is an effect caused by the periodicity of the composite material, we study in this work both periodic and aperiodic material samples.
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Proceedings of the Fourth European Conference on Antennas and Propagation, Apr 12, 2010
Combinations of electric and magnetic dipoles radiating circularly polarized waves are studied. T... more Combinations of electric and magnetic dipoles radiating circularly polarized waves are studied. The use of a chiral particle is introduced as a means to create a single radiating particle that combines an electric dipole and a magnetic dipole. It is shown both numerically and experimentally that a pair of two such particles, when fed with a 90 degree phase shift,
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Bookmarks Related papers MentionsView impact
New Journal of Physics, 2021
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We propose to use an antenna composed of two orthogonal helices as a low-scattering sensor. The v... more We propose to use an antenna composed of two orthogonal helices as a low-scattering sensor. The vector effective length is derived for the antenna using the small dipole approximation for the helices. The antenna can transmit and receive circular polarization in all directions with the Huygens' pattern. We observe that the antenna geometry does not backscatter, regardless of the polarization, when the incidence direction is normal to the plane of the helices. Scattered fields, scattered axial ratio, and the scattering cross section are presented. We show that the zero-backscattering property holds also for the antenna when it is capable to receive all the available power with conjugate loading. The approximate analytical model is validated with full-wave simulations.
Bookmarks Related papers MentionsView impact
We consider resonant patch antennas, implemented using loaded transmission-line networks and othe... more We consider resonant patch antennas, implemented using loaded transmission-line networks and other exotic structures having engineered dispersion. An analytical expression is derived for the ratio of radiation quality factors of such antennas and conventional patch antennas loaded with (reference) dielectrics. In the ideal case this ratio depends only on the propagation constant and wave impedance of the structure under test, and it can be conveniently used to study what kind of dispersion leads to improved impedance bandwidth. We illustrate the effect of dispersion by implementing a resonant patch antenna using a periodic network of LC elements. The analytical results predicting enhanced impedance bandwidth compared to the reference results are validated using a commercial circuit simulator. Discussion is conducted on the practical limitations for the use of the proposed expression.
Bookmarks Related papers MentionsView impact
Ieee Transactions on Antennas and Propagation, Oct 1, 2009
Bookmarks Related papers MentionsView impact
Journal of Electromagnetic Waves and Applications, 2003
... Abstract|New artifi cial reactive impedance surfaces have been re-cently suggested by Sievenp... more ... Abstract|New artifi cial reactive impedance surfaces have been re-cently suggested by Sievenpiper et al. ... 1. These novel artifi cial layers are also called 2D photonic (or electromagnetic, which is more appropriate for the frequency band of applications) bandgap structures. ...
Bookmarks Related papers MentionsView impact
Physical Review B Condensed Matter and Materials Physics, 2007
Bookmarks Related papers MentionsView impact
Physics Letters a, Apr 7, 2008
Bookmarks Related papers MentionsView impact
Unknown, Jun 1, 1989
ABSTRACT
Bookmarks Related papers MentionsView impact
IEE Proceedings H Microwaves, Antennas and Propagation, 1991
The paper explores reflection and transmission characteristics of single and multilayer chiral sl... more The paper explores reflection and transmission characteristics of single and multilayer chiral slabs. The analysis is based on vector circuit modelling of chiral slabs in terms of transverse fields, dyadic impedance, admittance or transmission matrix components. Reflection and transmission coefficients for arbitrary angles of incidence and arbitrary polarisation states of the fields are derived. From these coefficients and to exemplify the method, reflected and transmitted fields of the co- and cross-polarised waves are calculated in single and multilayer chiral slabs for various electromagnetic and geometrical parameter values.
Bookmarks Related papers MentionsView impact
Eprint Arxiv Physics 0504123, Apr 18, 2005
Bookmarks Related papers MentionsView impact
Abstract In this paper, two homogenization models are presented for the analysis of mushroom stru... more Abstract In this paper, two homogenization models are presented for the analysis of mushroom structures. The differences of these models rise from the different way of modeling the array of metallic vias connecting the metallic patches to the ground plane. It is shown that for electrically thin mushroom structures the results of these models concur with each other. Furthermore, it is shown in this paper that the use of metallic vias in mushroom structures results in additional resonances for the TM-polarized incident fields.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Nasa Sti Recon Technical Report N, Apr 1, 1989
The Silberstein wave-field decomposition of electromagnetic fields is applied to the problem of w... more The Silberstein wave-field decomposition of electromagnetic fields is applied to the problem of wave propagation in chiral medium. The problem involving a planar interface between two chiral media is considered and eigensolutions for the reflection and transmission problems are given. Numerical results are calculated for the eigenpolarizations and reflection coefficients with different incident field polarizations, for the problem involving an interface between isotropic and chiral media. Also, the limit cases of reflection from a half space with only small amount of chirality are studied and it is shown that the chirality gives a second-order effect on the co-polarized reflection coefficient and a first-order effect on cross-polarization.
Bookmarks Related papers MentionsView impact
Nasa Sti Recon Technical Report N, Dec 1, 1990
Bookmarks Related papers MentionsView impact
Cloaking using a volumetric structure composed of stacked two-dimensional transmission-line netwo... more Cloaking using a volumetric structure composed of stacked two-dimensional transmission-line networks is verified with measurements. The measurements are done in a waveguide, in which an array of metallic cylinders is inserted causing a short-circuit in the waveguide. The metal cylinders are cloaked using a previously designed and simulated cloak that hides the cylinders and thus enables wave propagation inside the waveguide.
Bookmarks Related papers MentionsView impact
Journal of Electromagnetic Waves and Applications, Apr 3, 2012
Bookmarks Related papers MentionsView impact
Proceedings of the 5th European Conference on Antennas and Propagation, Apr 11, 2011
ABSTRACT Electromagnetic cloaks based on volumetric transmission-line networks have been previous... more ABSTRACT Electromagnetic cloaks based on volumetric transmission-line networks have been previously proposed as candidates for simple, cheap, and broadband cloaking devices that can be used to hide mesh-like structures. In this paper we demonstrate, with numerical simulations, how a metallic object placed in the near-field of a horn antenna can be made “invisible” with such a cloak, thus restoring the antenna's radiation properties to resemble the case when the antenna is alone in free space.
Bookmarks Related papers MentionsView impact
2013 International Symposium on Electromagnetic Theory, 2013
ABSTRACT We study the occurrence of the so-called antiresonance in the material parameters (permi... more ABSTRACT We study the occurrence of the so-called antiresonance in the material parameters (permittivity, permeability) characterizing the electromagnetic response of a composite material slab. The material parameters are retrieved using the wellknown reflection/transmission method. As many previous works have either claimed or assumed that the antiresonance is an effect caused by the periodicity of the composite material, we study in this work both periodic and aperiodic material samples.
Bookmarks Related papers MentionsView impact
Proceedings of the Fourth European Conference on Antennas and Propagation, Apr 12, 2010
Combinations of electric and magnetic dipoles radiating circularly polarized waves are studied. T... more Combinations of electric and magnetic dipoles radiating circularly polarized waves are studied. The use of a chiral particle is introduced as a means to create a single radiating particle that combines an electric dipole and a magnetic dipole. It is shown both numerically and experimentally that a pair of two such particles, when fed with a 90 degree phase shift,
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Anisotropic materials with different signs of components of the permittivity tensor are called in... more Anisotropic materials with different signs of components of the permittivity tensor are called indefinite materials. Known realizations of indefinite media suffer of high absorption losses. We show that periodic arrays of parallel carbon nanotubes (CNTs) can behave as a low-loss indefinite medium in the infrared range. We show that a finite-thickness slab of CNTs supports the propagation of backward waves with small attenuation in an ultra-broad frequency band. In prospective, CNT arrays can be used for subwavelength focusing and detection, enhancing the radiation efficiency of small sources.
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IEEE Antennas and Wireless Propagation Letters, 2014
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