Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169418
R. D. Soares, R. Mesquita, F. Moreira
This work describes a meshless method to obtain the electromagnetic characteristics of a monopole placed over a perfectly electric ground plane. The Meshless Local Petrov-Galerkin is used with shape functions generated by Moving Least Squares. Boundary conditions are imposed by a collocation method that does not require any numerical integration. The proposed axisymmetric analysis has a simple implementation and reduced computational effort. The results are in agreement with theoretical data and simulations found in the literature.
{"title":"Electromagnetic axisymmetric analysis of monopole antenna over a perfectly electric ground plane by a Meshless Local Petrov-Galerkin method","authors":"R. D. Soares, R. Mesquita, F. Moreira","doi":"10.1109/IMOC.2011.6169418","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169418","url":null,"abstract":"This work describes a meshless method to obtain the electromagnetic characteristics of a monopole placed over a perfectly electric ground plane. The Meshless Local Petrov-Galerkin is used with shape functions generated by Moving Least Squares. Boundary conditions are imposed by a collocation method that does not require any numerical integration. The proposed axisymmetric analysis has a simple implementation and reduced computational effort. The results are in agreement with theoretical data and simulations found in the literature.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132633899","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 : 2011-10-01DOI: 10.1109/IMOC.2011.6169330
C. Vicente, V. Fernandes, Carlos Marques, P. Marques, E. Pecoraro, Rogério N. Nogueira, Luis D. Carlos, Rute A. S. Ferreira, P. André
High-rejection optical filters (~ 20 dB) based on first-order Bragg gratings inscribed in channel waveguides were fabricated using UV-laser direct-write method in sol-gel derived organic-inorganic hybrids, so-called di-ureasils, processed as good-optical quality thin films on oxidized silicon substrates. The gratings were designed to operate at communication wavelengths of 1550 nm demonstrating the great potential of sol-gel technology in the integration of optoelectronic components.
{"title":"High-rejection optical filters patterned on organic-inorganic hybrids using UV laser direct writing","authors":"C. Vicente, V. Fernandes, Carlos Marques, P. Marques, E. Pecoraro, Rogério N. Nogueira, Luis D. Carlos, Rute A. S. Ferreira, P. André","doi":"10.1109/IMOC.2011.6169330","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169330","url":null,"abstract":"High-rejection optical filters (~ 20 dB) based on first-order Bragg gratings inscribed in channel waveguides were fabricated using UV-laser direct-write method in sol-gel derived organic-inorganic hybrids, so-called di-ureasils, processed as good-optical quality thin films on oxidized silicon substrates. The gratings were designed to operate at communication wavelengths of 1550 nm demonstrating the great potential of sol-gel technology in the integration of optoelectronic components.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133365468","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 : 2011-10-01DOI: 10.1109/IMOC.2011.6169270
Rodrigo C. de Freitas, J. Martins-Filho, Rodrigo C. L. Silva, C. Bastos-Filho, Helder A. Pereira, D. Chaves
In this paper, we propose a novel algorithm to restore calls upon double-link failures in all-optical networks. Our proposal aims to restore all the lightpaths disrupted by each failure. The algorithm performs a path restoration looking for the route that presents the higher optical signal-to-noise ratio (OSNR). We compared our proposal to three other well known approaches in the literature. We observed that our proposal obtained lower failure rates in the restoration process for three different studied scenarios considering several physical layer impairments.
{"title":"A novel double-link failure restoration algorithm based on optical signal-to-noise ratio for all-optical networks","authors":"Rodrigo C. de Freitas, J. Martins-Filho, Rodrigo C. L. Silva, C. Bastos-Filho, Helder A. Pereira, D. Chaves","doi":"10.1109/IMOC.2011.6169270","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169270","url":null,"abstract":"In this paper, we propose a novel algorithm to restore calls upon double-link failures in all-optical networks. Our proposal aims to restore all the lightpaths disrupted by each failure. The algorithm performs a path restoration looking for the route that presents the higher optical signal-to-noise ratio (OSNR). We compared our proposal to three other well known approaches in the literature. We observed that our proposal obtained lower failure rates in the restoration process for three different studied scenarios considering several physical layer impairments.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129150282","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 : 2011-10-01DOI: 10.1109/IMOC.2011.6169352
Edgar Silva, Elisson A. D. Lima, G. Carrijo
In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved heuristic diffraction coefficient and investigate the diffraction contribution using a 3D UTD wedge diffraction for a LOS microcellular model. Our 3D street waveguide model congregates the derivation of a 3D precise ray-geometry, strict polarization, a 3D improved heuristic diffraction coefficient, and vectorial and field radiation pattern analyses.
{"title":"A three-dimensional microcellular Line-of-Sight propagation model using UTD wedge diffraction","authors":"Edgar Silva, Elisson A. D. Lima, G. Carrijo","doi":"10.1109/IMOC.2011.6169352","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169352","url":null,"abstract":"In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved heuristic diffraction coefficient and investigate the diffraction contribution using a 3D UTD wedge diffraction for a LOS microcellular model. Our 3D street waveguide model congregates the derivation of a 3D precise ray-geometry, strict polarization, a 3D improved heuristic diffraction coefficient, and vectorial and field radiation pattern analyses.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134398576","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 : 2011-10-01DOI: 10.1109/IMOC.2011.6169252
M. Fugihara, J. Marconi, F. Callegari, H. Fragnito
We present a field-trial evaluation of an in-line fiber optical parametric amplifier (FOPA) without polarization dependent gain (PDG). This parametric amplifier uses a polarization diversity technique (PDT) to reduce the PDG to less than 0.05 dB. We analyzed the performance of a system with an in-line FOPA comparing the results of its bit-error-rate (BER) with the BER of a system with an in-line Erbium doped fiber amplifier (EDFA). FOPA presented a power penalty that was 0.7dB higher than the one obtained with the EDFA, showing that the PDG was effectively suppressed with the PDT.
{"title":"Field-trial demonstration of a one-pump fiber optics parametric amplifier with independent polarization gain","authors":"M. Fugihara, J. Marconi, F. Callegari, H. Fragnito","doi":"10.1109/IMOC.2011.6169252","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169252","url":null,"abstract":"We present a field-trial evaluation of an in-line fiber optical parametric amplifier (FOPA) without polarization dependent gain (PDG). This parametric amplifier uses a polarization diversity technique (PDT) to reduce the PDG to less than 0.05 dB. We analyzed the performance of a system with an in-line FOPA comparing the results of its bit-error-rate (BER) with the BER of a system with an in-line Erbium doped fiber amplifier (EDFA). FOPA presented a power penalty that was 0.7dB higher than the one obtained with the EDFA, showing that the PDG was effectively suppressed with the PDT.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134092237","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 : 2011-10-01DOI: 10.1109/IMOC.2011.6169341
E. Almeida, F. de S. Chaves, R. Iida, E. Souza, R. Vieira
In order to have the White Spaces of the UHF broadcast band (470–790 MHz) in use by unlicensed users, new implementation challenges and special efforts still need to be done. Regulators can significantly impact the feasibility of implementation through requirements on sensing thresholds or by defining emission limits of unlicensed users. This paper addresses the emission limits of unlicensed users according to ECC approach, where the maximum output power is calculated for each location and for each device type/class. The problem of coexistence between white space devices and DTT broadcast service for the operation modes considered in CEPT is discussed and evaluated through simulations. With the obtained results, we discuss the relevancy of parameters stored in the geo-location database.
{"title":"Maximum permitted transmit power of white space devices operating on TV spectrum","authors":"E. Almeida, F. de S. Chaves, R. Iida, E. Souza, R. Vieira","doi":"10.1109/IMOC.2011.6169341","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169341","url":null,"abstract":"In order to have the White Spaces of the UHF broadcast band (470–790 MHz) in use by unlicensed users, new implementation challenges and special efforts still need to be done. Regulators can significantly impact the feasibility of implementation through requirements on sensing thresholds or by defining emission limits of unlicensed users. This paper addresses the emission limits of unlicensed users according to ECC approach, where the maximum output power is calculated for each location and for each device type/class. The problem of coexistence between white space devices and DTT broadcast service for the operation modes considered in CEPT is discussed and evaluated through simulations. With the obtained results, we discuss the relevancy of parameters stored in the geo-location database.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132858719","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 : 2011-10-01DOI: 10.1109/IMOC.2011.6169397
E. F. Melo, E. Fontana
Optical sensors based on the surface plasmon resonance (SPR) effect are generally designed in a prism coupling configuration. Metal gratings can also be used to support surface plasmons, in turn allowing for the design of alternative, SPR based, sensor configurations. Determination of design parameters for developing such sensors is an important step for fabrication of these devices. In this paper the spectral dependence of sinusoidal metal grating parameters, represented by amplitude and periodicity, for front surface sensors is calculated to allow maximum sensitivity of the device. Results may be an important tool for those investigators involved in developing new applications of the technique.
{"title":"Optimization of metal gratings for SPR sensing applications","authors":"E. F. Melo, E. Fontana","doi":"10.1109/IMOC.2011.6169397","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169397","url":null,"abstract":"Optical sensors based on the surface plasmon resonance (SPR) effect are generally designed in a prism coupling configuration. Metal gratings can also be used to support surface plasmons, in turn allowing for the design of alternative, SPR based, sensor configurations. Determination of design parameters for developing such sensors is an important step for fabrication of these devices. In this paper the spectral dependence of sinusoidal metal grating parameters, represented by amplitude and periodicity, for front surface sensors is calculated to allow maximum sensitivity of the device. Results may be an important tool for those investigators involved in developing new applications of the technique.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121974824","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 : 2011-10-01DOI: 10.1109/IMOC.2011.6169245
M. Heckler, A. Dreher
This paper presents the formulation to apply the discrete mode matching (DMM) method to analyze microstrip multilayer structures, such as transmission lines and antennas conformed to cylinders. The main advantage of the method is the need of discretization only along the azimuthal and the axial directions by sampling the fields and current densities in the interfaces between dielectric layers. The solution in the radial direction is obtained analytically with the dyadic Green's function, which is calculated using the full-wave equivalent circuit (FWEC) in the spectral domain. The method is used to analyze two structures: a multilayer conformal transmission line and a conformal antenna. Validation with the commercial software HFSS has been done and good agreement between the results has been observed.
{"title":"Discrete mode matching analysis of cylindrical microstrip structures","authors":"M. Heckler, A. Dreher","doi":"10.1109/IMOC.2011.6169245","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169245","url":null,"abstract":"This paper presents the formulation to apply the discrete mode matching (DMM) method to analyze microstrip multilayer structures, such as transmission lines and antennas conformed to cylinders. The main advantage of the method is the need of discretization only along the azimuthal and the axial directions by sampling the fields and current densities in the interfaces between dielectric layers. The solution in the radial direction is obtained analytically with the dyadic Green's function, which is calculated using the full-wave equivalent circuit (FWEC) in the spectral domain. The method is used to analyze two structures: a multilayer conformal transmission line and a conformal antenna. Validation with the commercial software HFSS has been done and good agreement between the results has been observed.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"167 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116602172","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 : 2011-10-01DOI: 10.1109/IMOC.2011.6169377
S. Bezerra, H. A. Cabral, M. T. de Melo
A new method for developing UMTS filters for upload and download bands is proposed. The filters are based on a periodical resonator called the H-type resonator. Simulation results show that the relative mean error is less than 1.5%. The filter designed by this method has an insertion loss less than 1dB and provides low return loss in the bandpass. A periodic network analysis was used for designing the H-type resonator. We have also derived a lumped-element circuit model for the filter whose element's values are found by using genetic algorithms. It is shown that the filter has a suitable frequency response, and that it can be applied quite well in telecommunication systems.
{"title":"A new procedure for developing UMTS filters based on periodic structures","authors":"S. Bezerra, H. A. Cabral, M. T. de Melo","doi":"10.1109/IMOC.2011.6169377","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169377","url":null,"abstract":"A new method for developing UMTS filters for upload and download bands is proposed. The filters are based on a periodical resonator called the H-type resonator. Simulation results show that the relative mean error is less than 1.5%. The filter designed by this method has an insertion loss less than 1dB and provides low return loss in the bandpass. A periodic network analysis was used for designing the H-type resonator. We have also derived a lumped-element circuit model for the filter whose element's values are found by using genetic algorithms. It is shown that the filter has a suitable frequency response, and that it can be applied quite well in telecommunication systems.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115173800","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 : 2011-10-01DOI: 10.1109/IMOC.2011.6169376
Victor S. C. Teichmann, A. Barreto, D. Mello
The widespread deployment of optical interconnects in data centers has renewed the interest in multimode fiber communications. Due to the complexity of modern transmission techniques, performance analysis relies on numerical simulations that require an accurate channel model to reflect reality with the needed precision. As there is no standard model for channel simulation, we investigate a deterministic, a statistical and the Cambridge 108 Fiber model for derivation of the multimode fiber (MMF) impulse response. Numerical simulations are performed in order to calculate the 3-dB bandwidth for each model. We show that the Cambridge model is generally a compromise between the statistical and the theoretical model, which seem to represent a pessimistic and an optimistic scenarios, respectively.
{"title":"Analysis of multimode fiber impulse response simulation models","authors":"Victor S. C. Teichmann, A. Barreto, D. Mello","doi":"10.1109/IMOC.2011.6169376","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169376","url":null,"abstract":"The widespread deployment of optical interconnects in data centers has renewed the interest in multimode fiber communications. Due to the complexity of modern transmission techniques, performance analysis relies on numerical simulations that require an accurate channel model to reflect reality with the needed precision. As there is no standard model for channel simulation, we investigate a deterministic, a statistical and the Cambridge 108 Fiber model for derivation of the multimode fiber (MMF) impulse response. Numerical simulations are performed in order to calculate the 3-dB bandwidth for each model. We show that the Cambridge model is generally a compromise between the statistical and the theoretical model, which seem to represent a pessimistic and an optimistic scenarios, respectively.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115443140","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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