scholarly journals Polarization conversion on nanostructured metallic surfaces fabricated by LIPSS

2019 ◽  
Author(s):  
Alejandro San-Blas ◽  
Noemi Casquero ◽  
Noemi Pérez ◽  
Miguel Martínez-Calderon ◽  
Luis M. Sanchez-Brea ◽  
...  
Keyword(s):  
Polarization Conversion ◽  
Metallic Surfaces

scholarly journals Simple design of efficient broadband multifunctional polarization converter for X-band applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thi Kim Thu Nguyen ◽  
Thi Minh Nguyen ◽  
Hong Quang Nguyen ◽  
Thanh Nghia Cao ◽  
Dac Tuyen Le ◽  
...  
Keyword(s):  
Circular Polarization ◽  
Incident Angle ◽  
Polarization Conversion ◽  
Simple Design ◽  
Cross Polarization ◽  
Polarization Converter ◽  
Frequency Bands ◽  
X Band ◽  
Cost Efficient ◽  
Patch Resonators

AbstractA simple design of a broadband multifunctional polarization converter using an anisotropic metasurface for X-band application is proposed. The proposed polarization converter consists of a periodic array of the two-corner-cut square patch resonators based on the FR-4 substrate that achieves both cross-polarization and linear-to-circular polarization conversions. The simulated results show that the polarization converter displays the linear cross-polarization conversion in the frequency range from 8 to 12 GHz with the polarization conversion efficiency above 90%. The efficiency is kept higher than 80% with wide incident angle up to 45°. Moreover, the proposed design achieves the linear-to-circular polarization conversion at two frequency bands of 7.42–7.6 GHz and 13–13.56 GHz. A prototype of the proposed polarization converter is fabricated and measured, showing a good agreement between the measured and simulated results. The proposed polarization converter exhibits excellent performances such as simple structure, multifunctional property, and large cost-efficient bandwidth and wide incident angle insensitivity in the linear cross polarization conversion, which can be useful for X-band applications. Furthermore, this structure can be extended to design broadband polarization converters in other frequency bands.

scholarly journals An Optimal Footprint Based Coverage Planning for Hydro Blasting Robots

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1194
Author(s):  
Thejus Pathmakumar ◽  
Madan Mohan Rayguru ◽  
Sriharsha Ghanta ◽  
Manivannan Kalimuthu ◽  
Mohan Rajesh Elara
Keyword(s):  
Genetic Algorithm ◽  
Mobile Robots ◽  
Numerical Simulations ◽  
Labour Force ◽  
Successful Implementation ◽  
Multi Objective Optimization ◽  
Metallic Surfaces ◽  
Industrial Sites ◽  
Experimental Trials ◽  
Time And Energy

The hydro blasting of metallic surfaces is an essential maintenance task in various industrial sites. Its requirement of a considerable labour force and time, calls for automating the hydro blasting jobs through mobile robots. A hydro blasting robot should be able to cover the required area for a successful implementation. If a conventional robot footprint is chosen, the blasting may become inefficient, even though the concerned area is completely covered. In this work, the blasting arm’s sweeping angle is chosen as the robot’s footprint for hydro blasting task, and a multi-objective optimization-based framework is proposed to compute the optimal sweeping arc. The genetic algorithm (GA) methodology is exploited to compute the optimal footprint, which minimizes the blasting time and energy simultaneously. Multiple numerical simulations are performed to show the effectiveness of the proposed approach. Moreover, the strategy is successfully implemented on our hydro blasting robot named Hornbill, and the efficacy of the proposed approach is validated through experimental trials.

scholarly journals Scattering Analysis and Efficiency Optimization of Dielectric Pancharatnam–Berry-Phase Metasurfaces

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 586
Author(s):  
Chen-Yi Yu ◽  
Qiu-Chun Zeng ◽  
Chih-Jen Yu ◽  
Chien-Yuan Han ◽  
Chih-Ming Wang
Keyword(s):  
Phase Modulation ◽  
Rotation Angle ◽  
Berry Phase ◽  
Fine Tuning ◽  
Design Rule ◽  
Polarization Conversion ◽  
Swarm Optimization ◽  
Efficiency Optimization ◽  
Phase Type ◽  
Gradient Phase

In this study, the phase modulation ability of a dielectric Pancharatnam–Berry (PB) phase metasurface, consisting of nanofins, is theoretically analyzed. It is generally considered that the optical thickness of the unit cell of a PB-phase metasurface is λ/2, i.e., a half-waveplate for polarization conversion. It is found that the λ/2 is not essential for achieving a full 2π modulation. Nevertheless, a λ/2 thickness is still needed for a high polarization conversion efficiency. Moreover, a gradient phase metasurface is designed. With the help of the particle swarm optimization (PSO) method, the wavefront errors of the gradient phase metasurface are reduced by fine-tuning the rotation angle of the nanofins. The diffraction efficiency of the gradient phase metasurface is thus improved from 73.4% to 87.3%. This design rule can be utilized to optimize the efficiency of phase-type meta-devices, such as meta-deflectors and metalenses.

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