The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Peter Uhd Jepsen - One of the best experts on this subject based on the ideXlab platform.
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terahertz Radar Cross Section measurements
Optics Express, 2010Co-Authors: Krzysztof Iwaszczuk, Henning Heiselberg, Peter Uhd JepsenAbstract:We perform angle- and frequency-resolved Radar Cross Section (RCS) measurements on objects at terahertz frequencies. Our RCS measurements are performed on a scale model aircraft of size 5-10 cm in polar and azimuthal configurations, and correspond closely to RCS measurements with conventional Radar on full-size objects. The measurements are performed in a terahertz time-domain system with freely propagating terahertz pulses generated by tilted pulse front excitation of lithium niobate crystals and measured with sub-picosecond time resolution. The application of a time domain system provides ranging information and also allows for identification of scattering points such as weaponry attached to the aircraft. The shapes of the models and positions of reflecting parts are retrieved by the filtered back projection algorithm.
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Terahertz Radar Cross Section measurements
35th International Conference on Infrared Millimeter and Terahertz Waves, 2010Co-Authors: Krzysztof Iwaszczuk, Henning Heiselberg, Peter Uhd JepsenAbstract:We present the result of terahertz Radar Cross Section measurements on various objects including models of aircraft fighters. Application of a time domain system provides both values of Radar Cross Section and ranging information.
Razvan D. Tamas - One of the best experts on this subject based on the ideXlab platform.
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Radar Cross Section analysis for meander line frequency selective surfaces
Advanced Topics in Optoelectronics Microelectronics and Nanotechnologies X, 2020Co-Authors: Stefania Bucuci, Razvan D. TamasAbstract:In this paper, we propose a Radar Cross Section analysis for frequency selective surfaces using a meander line antenna as a unit cell. The periodic structure consists of a passive copper antenna backed by a dielectric substrate. Two configurations of constant aperture composed of three and five elements are presented. The Radar Cross Section is evaluated by using a plane wave excitation with linear polarization in order to assess the ratio of the backscattered power.
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UWB-Radar Cross Section Measurements in the Fresnel Region and Real Environment
2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, Razvan D. TamasAbstract:This paper presents a novel method to approximate the specular Radar Cross Section of a flat plate (with known dimensions) in the Fresnel region. The proposed method relies on averaging the contribution from discrete current elements at the horn antenna aperture and discrete current elements on the target. The approximations made to estimate the phase difference result in the classical flat plate Radar Cross Section when the antennas-target distance approaches the far field. A computing time saving technique with Fresnel integrals is proposed in order to calculate the phase difference. The experimental validation of the proposed technique demonstrates reasonable agreement with the theoretical far field Radar Cross Section.
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A Bistatic Method for Radar Cross Section Measurements in the Fresnel Region
2019Co-Authors: Valentin Mihai, Razvan D. Tamas, Ala SharaihaAbstract:Fresnel region Radar Cross Section analysis becomes a reliable solution when far-field conditions are difficult to fulfil. An approximated analytical expression for the Radar Cross Section is derived based on the field integration on the target surface by assuming a constant current distribution on the transmitting antenna. The influences of environment and impedance mismatch are considered, provided that the measurements are performed in a multipath environment. Our method was validated by simulation and measurements on a rectangular, metallic plate.
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Radar Cross Section of a Slightly Tilted Disk in the Fresnel Region and Real Environment
2019 IEEE Conference on Antenna Measurements & Applications (CAMA), 2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, Razvan D. TamasAbstract:This paper presents a method to measure the Radar Cross Section of a disk (with known radius) at normal and oblique incidence in the Fresnel region and real environment. The proposed method relies both on the physical optics approach and averaging the field distribution over the transmitting and receiving antenna apertures. The ratio between the analytical expression of the Radar Cross Section at far-field and Fresnel region results in a transformation factor between both field zones. The RCS obtained through scattering parameters measured at Fresnel region distances is corrected with the analytical transformation factor previously determined. The measurements are in a good agreement with simulations and theoretical far field Radar Cross Section at normal and oblique incidence.
Krzysztof Iwaszczuk - One of the best experts on this subject based on the ideXlab platform.
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terahertz Radar Cross Section measurements
Optics Express, 2010Co-Authors: Krzysztof Iwaszczuk, Henning Heiselberg, Peter Uhd JepsenAbstract:We perform angle- and frequency-resolved Radar Cross Section (RCS) measurements on objects at terahertz frequencies. Our RCS measurements are performed on a scale model aircraft of size 5-10 cm in polar and azimuthal configurations, and correspond closely to RCS measurements with conventional Radar on full-size objects. The measurements are performed in a terahertz time-domain system with freely propagating terahertz pulses generated by tilted pulse front excitation of lithium niobate crystals and measured with sub-picosecond time resolution. The application of a time domain system provides ranging information and also allows for identification of scattering points such as weaponry attached to the aircraft. The shapes of the models and positions of reflecting parts are retrieved by the filtered back projection algorithm.
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Terahertz Radar Cross Section measurements
35th International Conference on Infrared Millimeter and Terahertz Waves, 2010Co-Authors: Krzysztof Iwaszczuk, Henning Heiselberg, Peter Uhd JepsenAbstract:We present the result of terahertz Radar Cross Section measurements on various objects including models of aircraft fighters. Application of a time domain system provides both values of Radar Cross Section and ranging information.
Ilie Valentin Mihai - One of the best experts on this subject based on the ideXlab platform.
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UWB-Radar Cross Section Measurements in the Fresnel Region and Real Environment
2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, R. TamasAbstract:This paper presents a novel method to approximate the specular Radar Cross Section of a flat plate (with known dimensions) in the Fresnel region. The proposed method relies on averaging the contribution from discrete current elements at the horn antenna aperture and discrete current elements on the target. The approximations made to estimate the phase difference result in the classical flat plate Radar Cross Section when the antennas-target distance approaches the far field. A computing time saving technique with Fresnel integrals is proposed in order to calculate the phase difference. The experimental validation of the proposed technique demonstrates reasonable agreement with the theoretical far field Radar Cross Section. © 2019 Antenna Branch of Chinese Institute of Electronics.
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Radar Cross Section of a Slightly Tilted Disk in the Fresnel Region and Real Environment
2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, R. TamasAbstract:This paper presents a method to measure the Radar Cross Section of a disk (with known radius) at normal and oblique incidence in the Fresnel region and real environment. The proposed method relies both on the physical optics approach and averaging the field distribution over the transmitting and receiving antenna apertures. The ratio between the analytical expression of the Radar Cross Section at far-field and Fresnel region results in a transformation factor between both field zones. The RCS obtained through scattering parameters measured at Fresnel region distances is corrected with the analytical transformation factor previously determined. The measurements are in a good agreement with simulations and theoretical far field Radar Cross Section at normal and oblique incidence. © 2019 IEEE.
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UWB-Radar Cross Section Measurements in the Fresnel Region and Real Environment
2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, Razvan D. TamasAbstract:This paper presents a novel method to approximate the specular Radar Cross Section of a flat plate (with known dimensions) in the Fresnel region. The proposed method relies on averaging the contribution from discrete current elements at the horn antenna aperture and discrete current elements on the target. The approximations made to estimate the phase difference result in the classical flat plate Radar Cross Section when the antennas-target distance approaches the far field. A computing time saving technique with Fresnel integrals is proposed in order to calculate the phase difference. The experimental validation of the proposed technique demonstrates reasonable agreement with the theoretical far field Radar Cross Section.
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Radar Cross Section of a Slightly Tilted Disk in the Fresnel Region and Real Environment
2019 IEEE Conference on Antenna Measurements & Applications (CAMA), 2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, Razvan D. TamasAbstract:This paper presents a method to measure the Radar Cross Section of a disk (with known radius) at normal and oblique incidence in the Fresnel region and real environment. The proposed method relies both on the physical optics approach and averaging the field distribution over the transmitting and receiving antenna apertures. The ratio between the analytical expression of the Radar Cross Section at far-field and Fresnel region results in a transformation factor between both field zones. The RCS obtained through scattering parameters measured at Fresnel region distances is corrected with the analytical transformation factor previously determined. The measurements are in a good agreement with simulations and theoretical far field Radar Cross Section at normal and oblique incidence.
Ala Sharaiha - One of the best experts on this subject based on the ideXlab platform.
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UWB-Radar Cross Section Measurements in the Fresnel Region and Real Environment
2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, R. TamasAbstract:This paper presents a novel method to approximate the specular Radar Cross Section of a flat plate (with known dimensions) in the Fresnel region. The proposed method relies on averaging the contribution from discrete current elements at the horn antenna aperture and discrete current elements on the target. The approximations made to estimate the phase difference result in the classical flat plate Radar Cross Section when the antennas-target distance approaches the far field. A computing time saving technique with Fresnel integrals is proposed in order to calculate the phase difference. The experimental validation of the proposed technique demonstrates reasonable agreement with the theoretical far field Radar Cross Section. © 2019 Antenna Branch of Chinese Institute of Electronics.
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Radar Cross Section of a Slightly Tilted Disk in the Fresnel Region and Real Environment
2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, R. TamasAbstract:This paper presents a method to measure the Radar Cross Section of a disk (with known radius) at normal and oblique incidence in the Fresnel region and real environment. The proposed method relies both on the physical optics approach and averaging the field distribution over the transmitting and receiving antenna apertures. The ratio between the analytical expression of the Radar Cross Section at far-field and Fresnel region results in a transformation factor between both field zones. The RCS obtained through scattering parameters measured at Fresnel region distances is corrected with the analytical transformation factor previously determined. The measurements are in a good agreement with simulations and theoretical far field Radar Cross Section at normal and oblique incidence. © 2019 IEEE.
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UWB-Radar Cross Section Measurements in the Fresnel Region and Real Environment
2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, Razvan D. TamasAbstract:This paper presents a novel method to approximate the specular Radar Cross Section of a flat plate (with known dimensions) in the Fresnel region. The proposed method relies on averaging the contribution from discrete current elements at the horn antenna aperture and discrete current elements on the target. The approximations made to estimate the phase difference result in the classical flat plate Radar Cross Section when the antennas-target distance approaches the far field. A computing time saving technique with Fresnel integrals is proposed in order to calculate the phase difference. The experimental validation of the proposed technique demonstrates reasonable agreement with the theoretical far field Radar Cross Section.
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A Bistatic Method for Radar Cross Section Measurements in the Fresnel Region
2019Co-Authors: Valentin Mihai, Razvan D. Tamas, Ala SharaihaAbstract:Fresnel region Radar Cross Section analysis becomes a reliable solution when far-field conditions are difficult to fulfil. An approximated analytical expression for the Radar Cross Section is derived based on the field integration on the target surface by assuming a constant current distribution on the transmitting antenna. The influences of environment and impedance mismatch are considered, provided that the measurements are performed in a multipath environment. Our method was validated by simulation and measurements on a rectangular, metallic plate.
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Radar Cross Section of a Slightly Tilted Disk in the Fresnel Region and Real Environment
2019 IEEE Conference on Antenna Measurements & Applications (CAMA), 2019Co-Authors: Ilie Valentin Mihai, Ala Sharaiha, Razvan D. TamasAbstract:This paper presents a method to measure the Radar Cross Section of a disk (with known radius) at normal and oblique incidence in the Fresnel region and real environment. The proposed method relies both on the physical optics approach and averaging the field distribution over the transmitting and receiving antenna apertures. The ratio between the analytical expression of the Radar Cross Section at far-field and Fresnel region results in a transformation factor between both field zones. The RCS obtained through scattering parameters measured at Fresnel region distances is corrected with the analytical transformation factor previously determined. The measurements are in a good agreement with simulations and theoretical far field Radar Cross Section at normal and oblique incidence.
