scholarly journals Tailoring the scattering properties of coding metamaterials based on machine learning

2021 ◽  
Vol 8 ◽  
pp. 15
Author(s):  
Shuai Yang ◽  
Kuang Zhang ◽  
Xumin Ding ◽  
Guohui Yang ◽  
Qun Wu
Keyword(s):  
Machine Learning ◽  
Genetic Algorithm ◽  
Pattern Analysis ◽  
Analytical Calculation ◽  
Scattering Pattern ◽  
Wave Simulation ◽  
Full Wave ◽  
Binary Coding ◽  
Calculation Results ◽  
Simulation Results

Diverse electromagnetic (EM) responses of coding metamaterials have been investigated, and the general research method is to use full-wave simulation. But if we only care its scattering properties, it is not necessary to perform full-wave simulation, which is usually time-consuming. Machine learning has significantly impelled the development of automatic design and optimize coding matrix. Based on metamaterial particle that has multiple response and genetic algorithm which is coupled with the scattering pattern analysis, we can optimize the coding matrix quickly to tailor the scattering properties without conducting full-wave simulation a lot of times for optimization. Since the coding matrix control of each particle allow modulation of EM wave, various EM phenomena can be achieved easier. In this paper, we proposed two reflective unitcells with different reflection phase, and then a semi-analytical model is built up for unitcells. To tailor the scattering properties, genetic algorithm normally based on binary coding, is coupled with the scattering pattern analysis in order to optimize the coding matrix. Finally, simulation results are compared with the semi-analytical calculation results and it is found that the simulation results agree very well with the theoretical values.

scholarly journals A Miniaturized Transmitting LPDA Design for 2 MHz–30 MHz Uses

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6034
Author(s):  
Wenjun Zhu ◽  
Lixin Guo
Keyword(s):  
High Frequency ◽  
Optimization Methods ◽  
Directional Pattern ◽  
Electrical Performance ◽  
Impedance Bandwidth ◽  
Gain Bandwidth ◽  
Wave Simulation ◽  
Full Wave ◽  
Coefficient Optimization ◽  
Simulation Results

A miniaturized horizontal polarized high frequency transmitting LPDA is presented. In use of the dipole transformation and antenna coefficient optimization methods, a 65% reduction in the size was achieved with the electrical performance kept in a competitive level. Full-wave simulation results showed a stable directional pattern and lower VSWR over the impedance bandwidth of 2 to 30 MHz. The gain bandwidth can reach the range of 4–30 MHz, meanwhile, there is only minor degradation on gain in frequencies under 4 MHz.

scholarly journals A Miniaturized Dual-Mode Bandpass Filter Using Slot Spurline Technique

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Haiwen Liu ◽  
Jiuhuai Lei ◽  
Jing Wan ◽  
Yan Wang ◽  
Feng Yang ◽  
...  
Keyword(s):  
Elliptic Function ◽  
Bandpass Filter ◽  
Dual Mode ◽  
Wave Simulation ◽  
Full Wave ◽  
Filter Characteristic ◽  
Simulation Results ◽  
Degenerate Modes ◽  
Good Agreement

A miniaturized dual-mode bandpass filter (BPF) with elliptic function response using slot spurline is designed in this paper. The slot spurline can not only splits the degenerate modes but also determine the type of filter characteristic (Chebyshev or elliptic). To miniaturize the resonator, four sagittate stubs are proposed. For demonstration purpose, a BPF operating at 5.75 GHz for WLAN application was designed, fabricated, and measured. The measured results are in good agreement with the full-wave simulation results.

scholarly journals Control of the Radiation Patterns Using Homogeneous and Isotropic Impedance Metasurface

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Fan Yang ◽  
Zhong Lei Mei ◽  
Tie Jun Cui
Keyword(s):  
Point Source ◽  
Surface Impedance ◽  
High Selectivity ◽  
Two Dimensional ◽  
Radiation Patterns ◽  
Wave Simulation ◽  
Full Wave ◽  
Low Profile ◽  
Simulation Results

We propose to control the radiation patterns of a two-dimensional (2D) point source by using impedance metasurfaces. We show that the radiation patterns can be manipulated by altering the surface impedance of the metasurface. Full-wave simulation results are provided to validate the theoretical derivations. The proposed design enjoys novel properties of isotropy, homogeneity, low profile, and high selectivity of frequency, making it potentially applicable in many applications. We also point out that this design can be implemented with active metasurfaces and the surface impedance can be tuned by modulating the value of loaded elements, like resistors, inductors, and capacitors.

scholarly journals Optimal allocation of microgrid using a differential multi-agent multi-objective evolution algorithm

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Liheng Liu ◽  
Miaomiao Niu ◽  
Dongliang Zhang ◽  
Li Liu ◽  
Dietmar Frank
Keyword(s):  
Genetic Algorithm ◽  
Optimal Allocation ◽  
Environmental Benefits ◽  
Nsga Ii ◽  
Multi Objective ◽  
Calculation Results ◽  
Key Issues ◽  
Multi Agent ◽  
Evolution Algorithm ◽  
Simulation Results

Abstract The optimal configuration and allocation of a microgrid are one of the key issues to guarantee the economic and reliable working of a microgrid. This is a multi-objective optimisation problem within which the economic index and the load power shortage rate index should be considered when optimising the configuration. In this article, a differential multi-agent multi-objective evolutionary algorithm (DMAMOEA) was designed to optimise the capacity configuration of a microgrid system, which includes three kinds of equipment: wind turbine, photovoltaic equipment and battery. The final optimisation results were compared with the Non-dominated Sorting Genetic Algorithm II (NSGA-II) algorithm. Simulation results showed the effectiveness of the algorithm. At the end of this article, the representative solutions in the calculation results are compared and explained and the environmental benefits are analysed, which show the effectiveness of the implementation of the microgrid system.

Tunable High-Q TSV Inductor Packaging with MEMS

2015 ◽  
Vol 2015 (1) ◽  
pp. 000062-000066 ◽  
Author(s):  
Bruce Kim ◽  
Saikat Mondal ◽  
Sang-Bock Cho
Keyword(s):  
Mechanical Systems ◽  
Micro Electro Mechanical Systems ◽  
Frequency Bands ◽  
High Isolation ◽  
High Q ◽  
Wave Simulation ◽  
Full Wave ◽  
Leakage Resistance ◽  
Simulation Results ◽  
Tunable Inductor

In this paper, we present a Through-Silicon-Via (TSV)-based 3D tunable inductor implementation for RF applications. The proposed inductor structure uses MEMS (Micro Electro-Mechanical Systems) switches to vary inductance by activating and deactivating the switches. MEMS-based switches are used to offer high isolation in the off state. The tunable inductor is tested within an LNA circuit for variation in off-state leakage resistance. Detailed 3D full wave simulation results are presented for different cellular frequency bands.

scholarly journals Analysis and Design of Ultra-Wideband 3-Way Bagley Power Divider Using Tapered Lines Transformers

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Khair Al Shamaileh ◽  
Abdullah Qaroot ◽  
Nihad Dib ◽  
Abdelfattah Sheta ◽  
Majeed A. Alkanhal
Keyword(s):  
Design Procedure ◽  
Ultra Wideband ◽  
Power Divider ◽  
Frequency Range ◽  
Analysis And Design ◽  
Wave Simulation ◽  
Full Wave ◽  
Quarter Wave ◽  
Simulation Results

An ultra-wideband (UWB) modified 3-way Bagley polygon power divider (BPD) that operates over a frequency range of 2–16 GHz is presented. To achieve the UWB operation, the conventional quarter-wave transformers in the BPD are substituted by two tapered line transformers. For verification purposes, the proposed divider is simulated, fabricated, and measured. The agreement between the full-wave simulation results and the measurement ones validates the design procedure.

Machine Learning Accelerated Genetic Algorithms for Computational Materials Search

2018 ◽  
Author(s):  
Steen Lysgaard ◽  
Paul C. Jennings ◽  
Jens Strabo Hummelshøj ◽  
Thomas Bligaard ◽  
Tejs Vegge
Keyword(s):  
Machine Learning ◽  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Au Nanoparticles ◽  
Learning Model ◽  
Energy Calculations ◽  
Atomic Distribution ◽  
Machine Learning Model ◽  
Fold Reduction ◽  
Computational Materials

A machine learning model is used as a surrogate fitness evaluator in a genetic algorithm (GA) optimization of the atomic distribution of Pt-Au nanoparticles. The machine learning accelerated genetic algorithm (MLaGA) yields a 50-fold reduction of required energy calculations compared to a traditional GA.

Task scheduling algorithm based on improved genetic algorithm in cloud computing environment

2020 ◽  
Vol 13 ◽  
Author(s):  
Ge Weiqing ◽  
Cui Yanru
Keyword(s):  
Genetic Algorithm ◽  
Cloud Computing ◽  
Task Scheduling ◽  
Scheduling Algorithm ◽  
Task Completion ◽  
Improved Genetic Algorithm ◽  
Fitness Functions ◽  
Task Scheduling Algorithm ◽  
Simulation Results

Background: In order to make up for the shortcomings of the traditional algorithm, Min-Min and Max-Min algorithm are combined on the basis of the traditional genetic algorithm. Methods: In this paper, a new cloud computing task scheduling algorithm is proposed, which introduces Min-Min and Max-Min algorithm to generate initialization population, and selects task completion time and load balancing as double fitness functions, which improves the quality of initialization population, algorithm search ability and convergence speed. Results: The simulation results show that the algorithm is superior to the traditional genetic algorithm and is an effective cloud computing task scheduling algorithm. Conclusion: Finally, this paper proposes the possibility of the fusion of the two quadratively improved algorithms and completes the preliminary fusion of the algorithm, but the simulation results of the new algorithm are not ideal and need to be further studied.

scholarly journals Modeling of German Low Voltage Cables with Ground Return Path

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1265 ◽  
Author(s):  
Johanna Geis-Schroer ◽  
Sebastian Hubschneider ◽  
Lukas Held ◽  
Frederik Gielnik ◽  
Michael Armbruster ◽  
...  
Keyword(s):  
Low Voltage ◽  
Measurement Data ◽  
Analytical Calculation ◽  
Laboratory Measurement ◽  
Model Parameters ◽  
Calculation Methods ◽  
Modeling Approach ◽  
Measurement Results ◽  
Simulation Results ◽  
Return Path

In this contribution, measurement data of phase, neutral, and ground currents from real low voltage (LV) feeders in Germany is presented and analyzed. The data obtained is used to review and evaluate common modeling approaches for LV systems. An alternative modeling approach for detailed cable and ground modeling, which allows for the consideration of typical German LV earthing conditions and asymmetrical cable design, is proposed. Further, analytical calculation methods for model parameters are described and compared to laboratory measurement results of real LV cables. The models are then evaluated in terms of parameter sensitivity and parameter relevance, focusing on the influence of conventionally performed simplifications, such as neglecting house junction cables, shunt admittances, or temperature dependencies. By comparing measurement data from a real LV feeder to simulation results, the proposed modeling approach is validated.

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