Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814302
Awanish Kumar, G. Reddy, S. Narayan
This paper presents a dual-band polarization-insensitive, highly angular stable and flexible EM wave absorber with low cross-polarization reflection. The proposed unit cell has two resonators C and D which offers absorptions at two distinct frequencies at 8.7 and 11.5 GHz frequency in the X band. This FSS unit cell structure has four-fold symmetry make it polarization-insensitive. The absorbance mechanism of the proposed structure is explained with the help of electric and magnetic coupling along with effective impedance plot. The simulation results reveal that for both bands, the proposed absorber is polarization insensitive and angular stable up to 600. Along with this study, reflection due to cross-polarization is also analyzed and included in the absorbance equation, confirming that the proposed design is an absorber, not a polarization converter. Finally, the absorber prototype is fabricated and tested under different conditions, and the measurement results perfectly match the simulation result, which verified that it is working.
{"title":"Dual-Band, Polarization Insensitive, and Flexible EM Wave Absorber with High Angular Stability and Low Cross Reflection Level","authors":"Awanish Kumar, G. Reddy, S. Narayan","doi":"10.23919/AT-AP-RASC54737.2022.9814302","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814302","url":null,"abstract":"This paper presents a dual-band polarization-insensitive, highly angular stable and flexible EM wave absorber with low cross-polarization reflection. The proposed unit cell has two resonators C and D which offers absorptions at two distinct frequencies at 8.7 and 11.5 GHz frequency in the X band. This FSS unit cell structure has four-fold symmetry make it polarization-insensitive. The absorbance mechanism of the proposed structure is explained with the help of electric and magnetic coupling along with effective impedance plot. The simulation results reveal that for both bands, the proposed absorber is polarization insensitive and angular stable up to 600. Along with this study, reflection due to cross-polarization is also analyzed and included in the absorbance equation, confirming that the proposed design is an absorber, not a polarization converter. Finally, the absorber prototype is fabricated and tested under different conditions, and the measurement results perfectly match the simulation result, which verified that it is working.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"518 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115350385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814421
R. Millan, J. Ripoll
This summary paper reports progress on an ongoing investigation of radiation belt electron pitch-angle scattering by plume hiss waves. We further analyze an electron precipitation event observed by BARREL, first reported in [1]. We find that the bremsstrahlung x-ray spectrum observed by BARREL is not consistent with an exponential precipitating electron energy spectrum, and is harder than the trapped electron spectrum measured by Van Allen Probes. We extend our quasi-linear diffusion model to consider a more realistic initial electron energy spectrum. The evolution of the electron phase space density towards a harder energy spectrum is qualitatively consistent with the BARREL observations and is attributed to the rapid loss of low energy particles at early times during their non-equilibrium interaction with the plume hiss waves.
{"title":"Fast Non-Equilibrium Pitch Angle Diffusion in a Plasmaspheric Plume Associated with BARREL Precipitation","authors":"R. Millan, J. Ripoll","doi":"10.23919/AT-AP-RASC54737.2022.9814421","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814421","url":null,"abstract":"This summary paper reports progress on an ongoing investigation of radiation belt electron pitch-angle scattering by plume hiss waves. We further analyze an electron precipitation event observed by BARREL, first reported in [1]. We find that the bremsstrahlung x-ray spectrum observed by BARREL is not consistent with an exponential precipitating electron energy spectrum, and is harder than the trapped electron spectrum measured by Van Allen Probes. We extend our quasi-linear diffusion model to consider a more realistic initial electron energy spectrum. The evolution of the electron phase space density towards a harder energy spectrum is qualitatively consistent with the BARREL observations and is attributed to the rapid loss of low energy particles at early times during their non-equilibrium interaction with the plume hiss waves.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121198448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814253
M. Lucido
In this paper, the surface plasmon resonances of a graphene disk stack, excited by an impinging plane wave, are studied by means of the guaranteed and fast convergence Helmholtz-Galerkin technique. The surface plasmon resonance frequencies are individuated by the peaks of the absorption cross-section and the total scattering cross-section, which are expressed in closed form. It is shown that, for a graphene disk stack with a small distance between the disks compared to the disks radius, the plasmon mode resonance frequencies up-shift as the number of disks increases.
{"title":"Analysis of the Surface Plasmon Resonances of a Graphene Disk Stack: A Guaranteed and Fast Convergence Method","authors":"M. Lucido","doi":"10.23919/AT-AP-RASC54737.2022.9814253","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814253","url":null,"abstract":"In this paper, the surface plasmon resonances of a graphene disk stack, excited by an impinging plane wave, are studied by means of the guaranteed and fast convergence Helmholtz-Galerkin technique. The surface plasmon resonance frequencies are individuated by the peaks of the absorption cross-section and the total scattering cross-section, which are expressed in closed form. It is shown that, for a graphene disk stack with a small distance between the disks compared to the disks radius, the plasmon mode resonance frequencies up-shift as the number of disks increases.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122054279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814396
M. Bevacqua, S. Zumbo, T. Isernia
In this contribution some recent advances in field intensity shaping paradigm are introduced and discussed, with particular emphasis on biomedical applications. Attention is focused on the design of the complex excitations feeding a biomedical array applicator such to ensure uniform and maximum field intensity distribution inside a given region of interest, while keeping it under control in some other regions. In particular, a smart procedure for the selection of the optimal phase shifts underlying multi control points-based approaches is introduced. Note that this procedure also plays a key role in other relevant non biomedical applications, including satellite and radio communications, as well as in antenna array synthesis theory.
{"title":"Some Improvements to Field Intensity Shaping for Biomedical Applications: Preliminary results","authors":"M. Bevacqua, S. Zumbo, T. Isernia","doi":"10.23919/AT-AP-RASC54737.2022.9814396","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814396","url":null,"abstract":"In this contribution some recent advances in field intensity shaping paradigm are introduced and discussed, with particular emphasis on biomedical applications. Attention is focused on the design of the complex excitations feeding a biomedical array applicator such to ensure uniform and maximum field intensity distribution inside a given region of interest, while keeping it under control in some other regions. In particular, a smart procedure for the selection of the optimal phase shifts underlying multi control points-based approaches is introduced. Note that this procedure also plays a key role in other relevant non biomedical applications, including satellite and radio communications, as well as in antenna array synthesis theory.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123766839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814195
Manoj Mani, Remsha Moolat, M. Pezholil
Characteristic mode analysis of a stepped impedance resonator (SIR) coupled dual-band dipole antenna is presented in this paper. Characteristic mode theory is effectively used to understand the resonant mechanism of the antenna. The antenna prototype is realized on the double-sided FR4 substrate of dielectric constant 4.4 and loss tangent 0.025. The proposed dual-band antenna resonates at 2.45 GHz and 5.5 GHz with an impedance bandwidth of 90 MHz and 1.6 GHz, respectively.
{"title":"Characteristic Mode Analysis of SIR Coupled Dual Band Dipole Antenna","authors":"Manoj Mani, Remsha Moolat, M. Pezholil","doi":"10.23919/AT-AP-RASC54737.2022.9814195","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814195","url":null,"abstract":"Characteristic mode analysis of a stepped impedance resonator (SIR) coupled dual-band dipole antenna is presented in this paper. Characteristic mode theory is effectively used to understand the resonant mechanism of the antenna. The antenna prototype is realized on the double-sided FR4 substrate of dielectric constant 4.4 and loss tangent 0.025. The proposed dual-band antenna resonates at 2.45 GHz and 5.5 GHz with an impedance bandwidth of 90 MHz and 1.6 GHz, respectively.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123888028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814325
Victor Paheco-Peña, N. Engheta
Temporal and spatiotemporally modulated media are becoming new paradigms for a full manipulation of electromagnetic wave propagation in four dimensions (x,y,z,t). Here we will give an overview of our recent efforts in exploiting temporal metamaterials where the permittivity of the medium where the wave travels is changed from isotropic to an anisotropic tensor. An indepth discussion will be presented during the conference demonstrating how such temporal boundaries can be engineered to achieve the temporal version of the spatial Brewster angle.
{"title":"What is the temporal analogue of the spatial Brewster angle?","authors":"Victor Paheco-Peña, N. Engheta","doi":"10.23919/AT-AP-RASC54737.2022.9814325","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814325","url":null,"abstract":"Temporal and spatiotemporally modulated media are becoming new paradigms for a full manipulation of electromagnetic wave propagation in four dimensions (x,y,z,t). Here we will give an overview of our recent efforts in exploiting temporal metamaterials where the permittivity of the medium where the wave travels is changed from isotropic to an anisotropic tensor. An indepth discussion will be presented during the conference demonstrating how such temporal boundaries can be engineered to achieve the temporal version of the spatial Brewster angle.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129229026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814354
E. Rojas, D. Hysell
In the present work we summarize our results on simulating Farley–Buneman instabilities for the first time using a fully fluid thermal model.
在本工作中，我们总结了首次使用全流体热模型模拟法利-布曼不稳定性的结果。
{"title":"Fluid simulation of the Farley–Buneman instability","authors":"E. Rojas, D. Hysell","doi":"10.23919/AT-AP-RASC54737.2022.9814354","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814354","url":null,"abstract":"In the present work we summarize our results on simulating Farley–Buneman instabilities for the first time using a fully fluid thermal model.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131155058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814405
F. Giannetti, A. Vaccaro, Fabiola Sapienza, G. Bacci, V. Lottici, L. Baldini
In this paper, we propose a novel opportunistic multi-satellite sensor system which overcomes the limitations of the conventional single-satellite solutions of the literature. The considerable robustness to the possible unavailability of some satellites, besides being well suited for powerful 2D reconstruction techniques of the rain field, makes it an appealing solution for experimental tests within national and EU-funded research projects.
{"title":"Multi-Satellite Rain Sensing: Design Criteria and Implementation Issues","authors":"F. Giannetti, A. Vaccaro, Fabiola Sapienza, G. Bacci, V. Lottici, L. Baldini","doi":"10.23919/AT-AP-RASC54737.2022.9814405","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814405","url":null,"abstract":"In this paper, we propose a novel opportunistic multi-satellite sensor system which overcomes the limitations of the conventional single-satellite solutions of the literature. The considerable robustness to the possible unavailability of some satellites, besides being well suited for powerful 2D reconstruction techniques of the rain field, makes it an appealing solution for experimental tests within national and EU-funded research projects.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130606404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814254
A. Yasyukevich, A. Vesnin
In the study, we carried out a joint analysis of the spatio-temporal dynamics of ionospheric and stratospheric short-period variability. We analyze the periods of winters of 2008–2009, 2012–2013, and 2018–2019, when strong midwinter sudden stratospheric warmings (SSW) occurred. During quiet winter periods, the stratospheric variability index is shown to be increased at a limited latitudinal interval of 40-65°N. Under SSW condition, the generation of disturbances in the stratosphere stops and a decrease in the stratosphere disturbance index appears. The index keeps low values for up to a month. The latitudinal-temporal distributions of the ionospheric TEC variability index vrTEC also show similar dynamics. The level of ionospheric variability decreases after the SSW onset in the stratosphere. The decrease in the short-period ionospheric variability can be explained by reduction of wave generation in the stratosphere, associated with the destruction of the jet stream during SSW periods.
{"title":"Short-period variability in the ionosphere and the stratosphere related to winter jet stream","authors":"A. Yasyukevich, A. Vesnin","doi":"10.23919/AT-AP-RASC54737.2022.9814254","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814254","url":null,"abstract":"In the study, we carried out a joint analysis of the spatio-temporal dynamics of ionospheric and stratospheric short-period variability. We analyze the periods of winters of 2008–2009, 2012–2013, and 2018–2019, when strong midwinter sudden stratospheric warmings (SSW) occurred. During quiet winter periods, the stratospheric variability index is shown to be increased at a limited latitudinal interval of 40-65°N. Under SSW condition, the generation of disturbances in the stratosphere stops and a decrease in the stratosphere disturbance index appears. The index keeps low values for up to a month. The latitudinal-temporal distributions of the ionospheric TEC variability index vrTEC also show similar dynamics. The level of ionospheric variability decreases after the SSW onset in the stratosphere. The decrease in the short-period ionospheric variability can be explained by reduction of wave generation in the stratosphere, associated with the destruction of the jet stream during SSW periods.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129311457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-29DOI: 10.23919/AT-AP-RASC54737.2022.9814251
F. Prol
This work provides a brief overview of the main challenges found by the author when developing a global ionospheric electron density estimation using tomography and Global Navigation Satellite System (GNSS) data.
{"title":"Challenges of Global-Scale Ionospheric Tomography using GNSS: A brief overview","authors":"F. Prol","doi":"10.23919/AT-AP-RASC54737.2022.9814251","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814251","url":null,"abstract":"This work provides a brief overview of the main challenges found by the author when developing a global ionospheric electron density estimation using tomography and Global Navigation Satellite System (GNSS) data.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130450174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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