Pub Date : 2015-11-01DOI: 10.1109/IMOC.2015.7369038
G. Santos, Samuel Gomes Quintanilha, Robert Kley Lagano, Marco Antonio Brasil Terada, Rafael Rabelo Nunes
This paper focus on studying techniques that allow optimization of a communication system by analyzing the patterns of antenna configurations and digital modulations. Antenna design methods are discussed, taking into account parameters such as the number of elements in arrays and modulation types. Computer simulations are made with the use of LTE system simulation and antenna packages freely available. The main goal is to investigate if the modulation scheme influences the antenna design.
{"title":"Optimization of antennas in communication systems: Digital modulation analysis","authors":"G. Santos, Samuel Gomes Quintanilha, Robert Kley Lagano, Marco Antonio Brasil Terada, Rafael Rabelo Nunes","doi":"10.1109/IMOC.2015.7369038","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369038","url":null,"abstract":"This paper focus on studying techniques that allow optimization of a communication system by analyzing the patterns of antenna configurations and digital modulations. Antenna design methods are discussed, taking into account parameters such as the number of elements in arrays and modulation types. Computer simulations are made with the use of LTE system simulation and antenna packages freely available. The main goal is to investigate if the modulation scheme influences the antenna design.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133356638","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 : 2015-11-01DOI: 10.1109/IMOC.2015.7369160
Pedro Luis Araujo Silva, Edmar Candeia Gurjão, G. Fontgalland
The Global Positioning System (GPS) is a worldwide service and it is used as a reference for many other time, altitude, latitude and longitude based systems. Intentional jammers can degrade the reception of GPS signals, causing the receivers to fall out of sync. The technique employed in Independent Components Analysis (ICA) provides the ability to separate the interference (jamming). In this paper, we analyze the influence of ICA parameters in the convergence and effectiveness of the method when applied to separate the GPS signal from the jamming from the received signal.
{"title":"Analysis of parameters for jamming separation in GPS signals using Independent Component Analysis","authors":"Pedro Luis Araujo Silva, Edmar Candeia Gurjão, G. Fontgalland","doi":"10.1109/IMOC.2015.7369160","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369160","url":null,"abstract":"The Global Positioning System (GPS) is a worldwide service and it is used as a reference for many other time, altitude, latitude and longitude based systems. Intentional jammers can degrade the reception of GPS signals, causing the receivers to fall out of sync. The technique employed in Independent Components Analysis (ICA) provides the ability to separate the interference (jamming). In this paper, we analyze the influence of ICA parameters in the convergence and effectiveness of the method when applied to separate the GPS signal from the jamming from the received signal.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129605820","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 : 2015-11-01DOI: 10.1109/IMOC.2015.7369168
A. Pedra, L. Caruso, P. Serafini, Á. Salles
Analysis, simulations and measurements of a single layer wide-band full E-shaped patch antenna using technique of shorting pins are presented and the antenna area is reduced. The resonance behavior of the E-antenna is studied and an antenna design procedure is developed. The antenna sensitivity is performed considering the parameter variations. An algorithm based on the FDTD was done by one of the authors.
{"title":"Analysis of a full E-shaped antenna","authors":"A. Pedra, L. Caruso, P. Serafini, Á. Salles","doi":"10.1109/IMOC.2015.7369168","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369168","url":null,"abstract":"Analysis, simulations and measurements of a single layer wide-band full E-shaped patch antenna using technique of shorting pins are presented and the antenna area is reduced. The resonance behavior of the E-antenna is studied and an antenna design procedure is developed. The antenna sensitivity is performed considering the parameter variations. An algorithm based on the FDTD was done by one of the authors.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114829735","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 : 2015-11-01DOI: 10.1109/IMOC.2015.7369156
J. Souza, K. Costa, Victor Dmitriev, F. Bamberg
This paper presents a theoretical analysis of an optical nanocircuit connected with broadband nanoantenna composed of electric and magnetic nanodipoles with feeding of the electric dipole only. The numerical analysis of the nanoantenna is performed by method of moments (MoM). The calculated results are input impedance, current distribution, reflection coefficient, radiation efficiency, bandwidth, voltage reflection coefficient and electric near field. Comsol Multiphysics software calculates some of these results. The results show that the loop inserted into the circuit increases the bandwidth of nanoantenna and decreases the overall voltage reflection coefficient of the optical nanocircuit.
{"title":"Combination of electrical and magnetic nanodipoles for broadband applications in optical nanocircuit","authors":"J. Souza, K. Costa, Victor Dmitriev, F. Bamberg","doi":"10.1109/IMOC.2015.7369156","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369156","url":null,"abstract":"This paper presents a theoretical analysis of an optical nanocircuit connected with broadband nanoantenna composed of electric and magnetic nanodipoles with feeding of the electric dipole only. The numerical analysis of the nanoantenna is performed by method of moments (MoM). The calculated results are input impedance, current distribution, reflection coefficient, radiation efficiency, bandwidth, voltage reflection coefficient and electric near field. Comsol Multiphysics software calculates some of these results. The results show that the loop inserted into the circuit increases the bandwidth of nanoantenna and decreases the overall voltage reflection coefficient of the optical nanocircuit.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134155469","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 : 2015-11-01DOI: 10.1109/IMOC.2015.7369044
A. G. Duarte, J. A. Apolinário, Jose C. A. Santos
Direction finding techniques can be applied to a number of military and civilian systems, such as radar, sonar, and radio communications. It aims at finding the Direction of Arrival of an electromagnetic source for positioning purposes. Direction finding systems can be primarily classified as multiple or single channel. The single-channel solution, investigated herein, is based on a switched antenna associated to a special Phase Locked Loop (PLL) receiver architecture that allows tracking the phase of each antenna. The PLL output is processed by a signal processing block that removes the ambiguity inherent to the PLL and estimates the angle of arrival of the source. This procedure is usually linked to high computational complexity that increases with the number of antennas and with the modulation level. This article proposes a technique to decrease the computational burden of the PLL-based single receiver DOA estimation scheme and to use the super resolution algorithm Multiple Emitter Location and Signal Parameter Estimation to obtain azimuth and zenith angles with improved accuracy. The simulated results using the novel algorithm are shown and its performance compared to the traditional solution in different scenarios.
{"title":"An efficient single receiver high resolution DOA estimation algorithm for modulated signals","authors":"A. G. Duarte, J. A. Apolinário, Jose C. A. Santos","doi":"10.1109/IMOC.2015.7369044","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369044","url":null,"abstract":"Direction finding techniques can be applied to a number of military and civilian systems, such as radar, sonar, and radio communications. It aims at finding the Direction of Arrival of an electromagnetic source for positioning purposes. Direction finding systems can be primarily classified as multiple or single channel. The single-channel solution, investigated herein, is based on a switched antenna associated to a special Phase Locked Loop (PLL) receiver architecture that allows tracking the phase of each antenna. The PLL output is processed by a signal processing block that removes the ambiguity inherent to the PLL and estimates the angle of arrival of the source. This procedure is usually linked to high computational complexity that increases with the number of antennas and with the modulation level. This article proposes a technique to decrease the computational burden of the PLL-based single receiver DOA estimation scheme and to use the super resolution algorithm Multiple Emitter Location and Signal Parameter Estimation to obtain azimuth and zenith angles with improved accuracy. The simulated results using the novel algorithm are shown and its performance compared to the traditional solution in different scenarios.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"527 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116579050","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 : 2015-11-01DOI: 10.1109/IMOC.2015.7369105
F. L. Cabrera, R. Feitoza, F. Rangel de Sousa
This paper presents a technique for extending the operating frequency of an inductive link used for wireless power transfer. The extension is achieved by segmenting the primary inductor. A circuit model is proposed for a single-coil squared inductor, which provides the basis for the model of the segmented inductor. These models help to understand the operation of the segmented inductor and serve as a guide to its design. A prototype of the link was fabricated, in which the primary inductor has an average diameter of 22mm and four segments. The secondary inductor has an average diameter of 4mm and the two inductors are expected to be optimally coupled at the distance of 15 mm. The operating frequency was experimentally validated to be 980MHz which is higher than the 415MHz measured for a conventional inductive link of same dimensions, while the link efficiency is maintained at the same value of 30%.
{"title":"Extending the inductor operating frequency for optimally-coupled wireless power transfer systems","authors":"F. L. Cabrera, R. Feitoza, F. Rangel de Sousa","doi":"10.1109/IMOC.2015.7369105","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369105","url":null,"abstract":"This paper presents a technique for extending the operating frequency of an inductive link used for wireless power transfer. The extension is achieved by segmenting the primary inductor. A circuit model is proposed for a single-coil squared inductor, which provides the basis for the model of the segmented inductor. These models help to understand the operation of the segmented inductor and serve as a guide to its design. A prototype of the link was fabricated, in which the primary inductor has an average diameter of 22mm and four segments. The secondary inductor has an average diameter of 4mm and the two inductors are expected to be optimally coupled at the distance of 15 mm. The operating frequency was experimentally validated to be 980MHz which is higher than the 415MHz measured for a conventional inductive link of same dimensions, while the link efficiency is maintained at the same value of 30%.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116607393","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 : 2015-11-01DOI: 10.1109/IMOC.2015.7369140
M. C. D. da Silva, V. Dmitriev, K. Q. da Costa
It is known that insertion of periodic cylindrical silver nanoantennas in organic thin-film solar cells increases efficiency of light absorption. In this study, we perform a geometric optimization of the nanoantennas by using genetic algorithm. Numerical calculations are based on the method of finite elements. Four types of new nanoantennas with different geometrical parameters were considered, namely, conical antenna, trunk of conical, trunk of conical exponential 1 and 2 ones. We have found that the trunk conical exponential 2 antenna provide a better solution for different angle of light incidence as compared with the others.
{"title":"Geometry optimization of plasmonic nanoantennas for organic solar cells","authors":"M. C. D. da Silva, V. Dmitriev, K. Q. da Costa","doi":"10.1109/IMOC.2015.7369140","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369140","url":null,"abstract":"It is known that insertion of periodic cylindrical silver nanoantennas in organic thin-film solar cells increases efficiency of light absorption. In this study, we perform a geometric optimization of the nanoantennas by using genetic algorithm. Numerical calculations are based on the method of finite elements. Four types of new nanoantennas with different geometrical parameters were considered, namely, conical antenna, trunk of conical, trunk of conical exponential 1 and 2 ones. We have found that the trunk conical exponential 2 antenna provide a better solution for different angle of light incidence as compared with the others.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125416746","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 : 2015-11-01DOI: 10.1109/IMOC.2015.7369220
T. A. Derzhavskaya, S. Glybovski, A. Hurshkainen, I. Melchakova, A. Raaijmakers, C. V. D. van den Berg
In this work we experimentally revise electromagnetic bandgap properties of high-impedance metasurfaces of the mushroom type and study their capabilities in decoupling elements of body-array coils for 7T MRI. We numerically optimize unit-cell parameters in order to improve isolation of densely packed dipole-type antennas operating at 298 MHz. We demonstrate by measurements, how the reachable isolation level depends on the distance to a phantom, the equivalent of human body tissues. The use of mushroom-type metasurface samples can potentially reduce SAR of prospective body-array coils due to reduction of inter-element coupling.
{"title":"Decoupling capabilities of mushroom-type high-impedance metasurfaces in 7T MRI applications","authors":"T. A. Derzhavskaya, S. Glybovski, A. Hurshkainen, I. Melchakova, A. Raaijmakers, C. V. D. van den Berg","doi":"10.1109/IMOC.2015.7369220","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369220","url":null,"abstract":"In this work we experimentally revise electromagnetic bandgap properties of high-impedance metasurfaces of the mushroom type and study their capabilities in decoupling elements of body-array coils for 7T MRI. We numerically optimize unit-cell parameters in order to improve isolation of densely packed dipole-type antennas operating at 298 MHz. We demonstrate by measurements, how the reachable isolation level depends on the distance to a phantom, the equivalent of human body tissues. The use of mushroom-type metasurface samples can potentially reduce SAR of prospective body-array coils due to reduction of inter-element coupling.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130416953","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 : 2015-11-01DOI: 10.1109/IMOC.2015.7369115
Joao Januario, M. Garrich, A. Bravalheri, Juliano R. F. Oliveira
Wavelength selective switch (WSS)-based reconfigurable optical add/drop multiplexers (ROADMs) are key elements in current operator's optical networks since they route signals directly in the optical domain. WSS-based ROADMs use a controller per site to guarantee a target power per channel over time following a distributed approach. The simultaneous and independent operation of the cascaded ROADMs' controllers quickly increase optical power fluctuations (or abrupt power losses) leading to undesired overshoots that impair system operation. This paper first reviews different controllers for both industrial applications and optical devices. Second, the overshoot problem is stated and experimentally validated when such controllers are used for ROADMs deployed in cascade. Third, enhancement techniques for the reviewed controllers are proposed to overcome the overshoot problem in current distributed network scenarios. Finally, trade-offs between transient amplitude response and convergence time are analyzed using a cost function approach.
{"title":"Modeling and analysis of transient response for cascaded WSS-based ROADMs","authors":"Joao Januario, M. Garrich, A. Bravalheri, Juliano R. F. Oliveira","doi":"10.1109/IMOC.2015.7369115","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369115","url":null,"abstract":"Wavelength selective switch (WSS)-based reconfigurable optical add/drop multiplexers (ROADMs) are key elements in current operator's optical networks since they route signals directly in the optical domain. WSS-based ROADMs use a controller per site to guarantee a target power per channel over time following a distributed approach. The simultaneous and independent operation of the cascaded ROADMs' controllers quickly increase optical power fluctuations (or abrupt power losses) leading to undesired overshoots that impair system operation. This paper first reviews different controllers for both industrial applications and optical devices. Second, the overshoot problem is stated and experimentally validated when such controllers are used for ROADMs deployed in cascade. Third, enhancement techniques for the reviewed controllers are proposed to overcome the overshoot problem in current distributed network scenarios. Finally, trade-offs between transient amplitude response and convergence time are analyzed using a cost function approach.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127342209","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 : 2015-11-01DOI: 10.1109/IMOC.2015.7369136
V. Dmitriev, Gustavo Tavares, C. Nascimento
In this paper we suggest and analyze numerically an electromagnetic filter for THz region. The filter is made of a frequency selective surface based on graphene elements placed on a dielectric substrate. The unit cell of the device represents a square lattice in which two graphene crosses are placed on both sides of a dielectric substrate. The two graphene elements interact and resonate with two dipole plasmonic modes with different frequencies due to difference in the geometrical sizes of the crosses. In the frequency between these two resonances there is a transparency window that characterizes the filtering property of the device. This effect can be explained by Fano resonance. The device operates at the central frequency 2.3 THz with the reflection and the transmission coefficients equal to -18.6 dB and -0.92 dB, respectively. We show also that the position of the transmission peak can be tuned by changing the chemical potential of the graphene.
{"title":"Graphene terahertz filter","authors":"V. Dmitriev, Gustavo Tavares, C. Nascimento","doi":"10.1109/IMOC.2015.7369136","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369136","url":null,"abstract":"In this paper we suggest and analyze numerically an electromagnetic filter for THz region. The filter is made of a frequency selective surface based on graphene elements placed on a dielectric substrate. The unit cell of the device represents a square lattice in which two graphene crosses are placed on both sides of a dielectric substrate. The two graphene elements interact and resonate with two dipole plasmonic modes with different frequencies due to difference in the geometrical sizes of the crosses. In the frequency between these two resonances there is a transparency window that characterizes the filtering property of the device. This effect can be explained by Fano resonance. The device operates at the central frequency 2.3 THz with the reflection and the transmission coefficients equal to -18.6 dB and -0.92 dB, respectively. We show also that the position of the transmission peak can be tuned by changing the chemical potential of the graphene.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129241921","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：