The Experts below are selected from a list of 5979 Experts worldwide ranked by ideXlab platform

Etienne Perret - One of the best experts on this subject based on the ideXlab platform.

  • displacement sensor based on Radar cross polarization measurements
    IEEE Transactions on Microwave Theory and Techniques, 2017
    Co-Authors: Etienne Perret
    Abstract:

    This paper presents the feasibility of measuring submillimeter displacements of objects in real environments using simple resonant Radar targets. These scatterers, also known as chipless tags, have their own Radar Signature that can be used not only for identification but also for sensing. The chipless radio frequency identification (RFID) is a highly promising technology, since it paves the way for the development of easily implementable communication systems where tags have costs similar to barcodes. Object displacements are extracted by just evaluating at different times the variation of the signals backscattered in cross polarization from the tags. Based on this analog RFID sensing principle, an analytical model is developed to perform the direct derivation of the displacements. Therefore, the approach does not require complex and specific calibration procedures based on lookup table for compensating variations due to the presence of surrounding unknown objects. It is possible to add this functionality to already designed chipless RFID tag operating in cross polarization without decreasing their coding capacity. Experimentations inside and outside anechoic chamber have been done, and a very good agreement was obtained with simulations. It has been proved that submillimeter displacements can be monitored with this approach. A chipless tag displacement of 0.5 mm with less than $\pm 45~\mu \text{m}$ error can be detected in real environment for a read range of up to 40 cm.

  • displacement sensor based on Radar cross polarization measurements
    IEEE Transactions on Microwave Theory and Techniques, 2017
    Co-Authors: Etienne Perret
    Abstract:

    This paper presents the feasibility of measuring submillimeter displacements of objects in real environments using simple resonant Radar targets. These scatterers, also known as chipless tags, have their own Radar Signature that can be used not only for identification but also for sensing. The chipless radio frequency identification (RFID) is a highly promising technology, since it paves the way for the development of easily implementable communication systems where tags have costs similar to barcodes. Object displacements are extracted by just evaluating at different times the variation of the signals backscattered in cross polarization from the tags. Based on this analog RFID sensing principle, an analytical model is developed to perform the direct derivation of the displacements. Therefore, the approach does not require complex and specific calibration procedures based on lookup table for compensating variations due to the presence of surrounding unknown objects. It is possible to add this functionality to already designed chipless RFID tag operating in cross polarization without decreasing their coding capacity. Experimentations inside and outside anechoic chamber have been done, and a very good agreement was obtained with simulations. It has been proved that submillimeter displacements can be monitored with this approach. A chipless tag displacement of 0.5 mm with less than $\pm 45~\mu \text{m}$ error can be detected in real environment for a read range of up to 40 cm.

Agostino Monorchio - One of the best experts on this subject based on the ideXlab platform.

  • wideband Radar cross section reduction of slot antennas arrays
    IEEE Transactions on Antennas and Propagation, 2014
    Co-Authors: Simone Genovesi, Filippo Costa, Agostino Monorchio
    Abstract:

    A comprehensive analysis aimed at reducing the Radar cross section (RCS) of array antennas, preserving at the same time their radiating performance, is presented. A microstrip slot array is considered as a test case to illustrate the proposed strategy for Radar cross section reduction (RCSR). It is shown that a remarkable reduction of the Radar Signature can be accomplished over a frequency band as wide as two octaves by employing an array of periodic resistive elements in front of the radiating apertures. The monostatic and bistatic RCS of the proposed structures are investigated both for normal and oblique incidence. Different arrangements and geometries of the periodic resistive pattern are thoroughly analyzed showing the benefits and the drawbacks in terms of antenna gain and level of the scattered fields. Furthermore, the use of metallic parasitic elements for enhancing the antenna gain is considered, and the scattering phenomena caused by their presence are addressed, taking into account the appearance of grating lobes. The antenna designs are also analyzed by resorting to a bidimensional color plot presenting the variation of the reradiated field both in frequency and spatial domain. The guidelines illustrated by the proposed examples can be easily applied to other antenna architectures.

  • low profile array with reduced Radar cross section by using hybrid frequency selective surfaces
    IEEE Transactions on Antennas and Propagation, 2012
    Co-Authors: Simone Genovesi, Filippo Costa, Agostino Monorchio
    Abstract:

    A solution for reducing the Radar cross section (RCS) of a microstrip antenna based on the use of frequency selective surfaces (FSSs) is described. The goal is accomplished by replacing the solid ground plane of the device with a hybrid structure comprising a suitable FSS. The behavior of the hybrid ground plane illuminated by a plane wave is analyzed by using a periodic method of moments (PMM), and it is modeled by resorting to a transmission-line equivalent circuit. Similarly, the propagation of the quasi-TEM mode along the modified feeding line of the array is represented by an equivalent circuit for surface waves. The two simplified analyses provide useful design criteria for the hybrid ground structure. The presented solution guarantees a decrease of the out-of-band Radar Signature of the target while preserving the desired in-band radiation characteristics of the low-profile array. A careful comparison to alternative configurations employing different ground planes has revealed the superior performance of the proposed design. Measurements on a realized prototype show a good agreement with simulations and prove the reliability of the design approach.

Simone Genovesi - One of the best experts on this subject based on the ideXlab platform.

  • wideband Radar cross section reduction of slot antennas arrays
    IEEE Transactions on Antennas and Propagation, 2014
    Co-Authors: Simone Genovesi, Filippo Costa, Agostino Monorchio
    Abstract:

    A comprehensive analysis aimed at reducing the Radar cross section (RCS) of array antennas, preserving at the same time their radiating performance, is presented. A microstrip slot array is considered as a test case to illustrate the proposed strategy for Radar cross section reduction (RCSR). It is shown that a remarkable reduction of the Radar Signature can be accomplished over a frequency band as wide as two octaves by employing an array of periodic resistive elements in front of the radiating apertures. The monostatic and bistatic RCS of the proposed structures are investigated both for normal and oblique incidence. Different arrangements and geometries of the periodic resistive pattern are thoroughly analyzed showing the benefits and the drawbacks in terms of antenna gain and level of the scattered fields. Furthermore, the use of metallic parasitic elements for enhancing the antenna gain is considered, and the scattering phenomena caused by their presence are addressed, taking into account the appearance of grating lobes. The antenna designs are also analyzed by resorting to a bidimensional color plot presenting the variation of the reradiated field both in frequency and spatial domain. The guidelines illustrated by the proposed examples can be easily applied to other antenna architectures.

  • low profile array with reduced Radar cross section by using hybrid frequency selective surfaces
    IEEE Transactions on Antennas and Propagation, 2012
    Co-Authors: Simone Genovesi, Filippo Costa, Agostino Monorchio
    Abstract:

    A solution for reducing the Radar cross section (RCS) of a microstrip antenna based on the use of frequency selective surfaces (FSSs) is described. The goal is accomplished by replacing the solid ground plane of the device with a hybrid structure comprising a suitable FSS. The behavior of the hybrid ground plane illuminated by a plane wave is analyzed by using a periodic method of moments (PMM), and it is modeled by resorting to a transmission-line equivalent circuit. Similarly, the propagation of the quasi-TEM mode along the modified feeding line of the array is represented by an equivalent circuit for surface waves. The two simplified analyses provide useful design criteria for the hybrid ground structure. The presented solution guarantees a decrease of the out-of-band Radar Signature of the target while preserving the desired in-band radiation characteristics of the low-profile array. A careful comparison to alternative configurations employing different ground planes has revealed the superior performance of the proposed design. Measurements on a realized prototype show a good agreement with simulations and prove the reliability of the design approach.

Yang Ruigang - One of the best experts on this subject based on the ideXlab platform.

  • electromagnetic properties and microwave absorption properties of batio3 carbonyl iron composite in s and c bands
    Journal of Magnetism and Magnetic Materials, 2011
    Co-Authors: Yang Ruigang
    Abstract:

    Abstract BaTiO 3 powders are prepared by sol–gel method. The carbonyl iron powder is prepared via thermal decomposition of iron pentacarbonyl. Then BaTiO 3 –carbonyl iron composite with different mixture ratios was prepared using the as-prepared material. The structure, morphology, and properties of the composites are characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, scanning electron microscopy (SEM), and a network analyzer. The complex permittivity and reflection loss of the composites have been measured at different microwave frequencies in S- and C-bands employing vector network analyzer model PNA 3629D vector. The effect of the mass ratio of BaTiO 3 /carbonyl iron on the microwave loss properties of the composites is investigated. A possible microwave absorbing mechanism of BaTiO 3 –carbonyl iron composite has been proposed. The BaTiO 3 –carbonyl iron composite can find applications in suppression of electromagnetic interference, and reduction of Radar Signature.

Filippo Costa - One of the best experts on this subject based on the ideXlab platform.

  • wideband Radar cross section reduction of slot antennas arrays
    IEEE Transactions on Antennas and Propagation, 2014
    Co-Authors: Simone Genovesi, Filippo Costa, Agostino Monorchio
    Abstract:

    A comprehensive analysis aimed at reducing the Radar cross section (RCS) of array antennas, preserving at the same time their radiating performance, is presented. A microstrip slot array is considered as a test case to illustrate the proposed strategy for Radar cross section reduction (RCSR). It is shown that a remarkable reduction of the Radar Signature can be accomplished over a frequency band as wide as two octaves by employing an array of periodic resistive elements in front of the radiating apertures. The monostatic and bistatic RCS of the proposed structures are investigated both for normal and oblique incidence. Different arrangements and geometries of the periodic resistive pattern are thoroughly analyzed showing the benefits and the drawbacks in terms of antenna gain and level of the scattered fields. Furthermore, the use of metallic parasitic elements for enhancing the antenna gain is considered, and the scattering phenomena caused by their presence are addressed, taking into account the appearance of grating lobes. The antenna designs are also analyzed by resorting to a bidimensional color plot presenting the variation of the reradiated field both in frequency and spatial domain. The guidelines illustrated by the proposed examples can be easily applied to other antenna architectures.

  • low profile array with reduced Radar cross section by using hybrid frequency selective surfaces
    IEEE Transactions on Antennas and Propagation, 2012
    Co-Authors: Simone Genovesi, Filippo Costa, Agostino Monorchio
    Abstract:

    A solution for reducing the Radar cross section (RCS) of a microstrip antenna based on the use of frequency selective surfaces (FSSs) is described. The goal is accomplished by replacing the solid ground plane of the device with a hybrid structure comprising a suitable FSS. The behavior of the hybrid ground plane illuminated by a plane wave is analyzed by using a periodic method of moments (PMM), and it is modeled by resorting to a transmission-line equivalent circuit. Similarly, the propagation of the quasi-TEM mode along the modified feeding line of the array is represented by an equivalent circuit for surface waves. The two simplified analyses provide useful design criteria for the hybrid ground structure. The presented solution guarantees a decrease of the out-of-band Radar Signature of the target while preserving the desired in-band radiation characteristics of the low-profile array. A careful comparison to alternative configurations employing different ground planes has revealed the superior performance of the proposed design. Measurements on a realized prototype show a good agreement with simulations and prove the reliability of the design approach.