Konstantinos Papadopoulos | National Technical University of Athens (original) (raw)
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Papers by Konstantinos Papadopoulos
… of Integrated Care, Jan 1, 2012
Abstract This paper describes an ICT platform aiming to support the well-being of frail elderly p... more Abstract This paper describes an ICT platform aiming to support the well-being of frail elderly people and facilitate them to stay longer and more healthily in their own home. Its principal characteristic is the combination of Telehealth and Telecare monitoring in a unified way, ...
Antennas and …, Jan 1, 2009
... In order to achieve optimal antenna performance, designers conduct iterative simulations so a... more ... In order to achieve optimal antenna performance, designers conduct iterative simulations so as to obtain the best values for each ... In order to evaluate the performance of the .distributedoptimization platform, a planar switched-beam antenna array design problem has been ...
Progress In …, Jan 1, 2011
Phased array antennas are a viable solution to a number of problems related to radio communicatio... more Phased array antennas are a viable solution to a number of problems related to radio communications applications. In this work, the multi-objective stochastic MOPSO algorithm is used to optimize the spatial configuration of a symmetric phased linear array. The defined optimization goals were the suppression of the radiation pattern sidelobes at a specified maximum scan angle as well as the minimization of the induced voltages correlation at the receiver frontend in order to maximize diversity performance. Non-linear constraints were enforced on the solution set, related to the multi-antenna system aperture efficiency and related to the mismatching when the array is scanned. The obtained optimized configurations for an array composed of 16 dipoles resulted in reducing the sidelobes up to 2.5 dB, when scanned 60 • away from broadside, compared to a linear array with elements spaced λ/2 apart. Furthermore, the optimized dipole arrays were characterized by a maximum element correlation of 0.12 to 0.43. The performance of obtained configurations was shown to be tolerant to feed phase variations that appear in realistic implementations. The arrays were analyzed employing the Method of Moments (MoM).
… 2009. EuCAP 2009 …, Jan 1, 2009
Beam forming systems using adaptive array antennas are a viable solution to a number of problems ... more Beam forming systems using adaptive array antennas are a viable solution to a number of problems in applications related to mobile communications. Genetic Algorithms and Particle Swarm Optimization have been extensively used in electromagnetic optimization and antenna design problems. In this paper two smart antennas are investigated, with the purpose to determine the appropriate configuration for each element of the array. The directional patterns of the antenna arrays vary as well as the corresponding geometry; a linear array, composed of 16 elements, for a base station application and a planar uniform circular array (PUCA) composed of 18 radiators. The synthesis problem addressed is to find spatial and feeding configuration of the radiators that conform to certain design constraints. Synchronous GA and PSO algorithms have been utilized to perform beam array optimization for the smart antenna systems. Their efficiency is evaluated on the basis of convergence to the optimal solution for the corresponding problem and convergence speed. The proposed methodology is very flexible allowing the incorporation of additional factors as coupling characteristics.
… 2006. EuCAP 2006 …, Jan 1, 2006
... results of the proposed optimization technique (utilizing FF 1) in the synthesis of an antenn... more ... results of the proposed optimization technique (utilizing FF 1) in the synthesis of an antenna consisting of ... Figure 6: Computed array Factors over beam angles (linear and polar) ... A novel switched beam array synthesis technique has been presented based on the Particle Swarm ...
… of Integrated Care, Jan 1, 2012
Abstract This paper describes an ICT platform aiming to support the well-being of frail elderly p... more Abstract This paper describes an ICT platform aiming to support the well-being of frail elderly people and facilitate them to stay longer and more healthily in their own home. Its principal characteristic is the combination of Telehealth and Telecare monitoring in a unified way, ...
Antennas and …, Jan 1, 2009
... In order to achieve optimal antenna performance, designers conduct iterative simulations so a... more ... In order to achieve optimal antenna performance, designers conduct iterative simulations so as to obtain the best values for each ... In order to evaluate the performance of the .distributedoptimization platform, a planar switched-beam antenna array design problem has been ...
Progress In …, Jan 1, 2011
Phased array antennas are a viable solution to a number of problems related to radio communicatio... more Phased array antennas are a viable solution to a number of problems related to radio communications applications. In this work, the multi-objective stochastic MOPSO algorithm is used to optimize the spatial configuration of a symmetric phased linear array. The defined optimization goals were the suppression of the radiation pattern sidelobes at a specified maximum scan angle as well as the minimization of the induced voltages correlation at the receiver frontend in order to maximize diversity performance. Non-linear constraints were enforced on the solution set, related to the multi-antenna system aperture efficiency and related to the mismatching when the array is scanned. The obtained optimized configurations for an array composed of 16 dipoles resulted in reducing the sidelobes up to 2.5 dB, when scanned 60 • away from broadside, compared to a linear array with elements spaced λ/2 apart. Furthermore, the optimized dipole arrays were characterized by a maximum element correlation of 0.12 to 0.43. The performance of obtained configurations was shown to be tolerant to feed phase variations that appear in realistic implementations. The arrays were analyzed employing the Method of Moments (MoM).
… 2009. EuCAP 2009 …, Jan 1, 2009
Beam forming systems using adaptive array antennas are a viable solution to a number of problems ... more Beam forming systems using adaptive array antennas are a viable solution to a number of problems in applications related to mobile communications. Genetic Algorithms and Particle Swarm Optimization have been extensively used in electromagnetic optimization and antenna design problems. In this paper two smart antennas are investigated, with the purpose to determine the appropriate configuration for each element of the array. The directional patterns of the antenna arrays vary as well as the corresponding geometry; a linear array, composed of 16 elements, for a base station application and a planar uniform circular array (PUCA) composed of 18 radiators. The synthesis problem addressed is to find spatial and feeding configuration of the radiators that conform to certain design constraints. Synchronous GA and PSO algorithms have been utilized to perform beam array optimization for the smart antenna systems. Their efficiency is evaluated on the basis of convergence to the optimal solution for the corresponding problem and convergence speed. The proposed methodology is very flexible allowing the incorporation of additional factors as coupling characteristics.
… 2006. EuCAP 2006 …, Jan 1, 2006
... results of the proposed optimization technique (utilizing FF 1) in the synthesis of an antenn... more ... results of the proposed optimization technique (utilizing FF 1) in the synthesis of an antenna consisting of ... Figure 6: Computed array Factors over beam angles (linear and polar) ... A novel switched beam array synthesis technique has been presented based on the Particle Swarm ...