Design & Optimization of Large Cylindrical Radomes with Subcell and Non-Orthogonal FDTD Meshes Combined with Genetic Algorithms
The word radome is a contraction of <i>radar</i> and <i>dome</i>. The function of radomes is to protect antennas from atmospheric agents. Radomes are closed structures that protect the antennas from environmental factors such as wind, rain, ice, sand, and ultraviolet rays, am...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-09-01
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| Series: | Electronics |
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| Online Access: | https://www.mdpi.com/2079-9292/10/18/2263 |
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| author | Enrique A. Navarro Jorge A. Portí Alfonso Salinas Enrique Navarro-Modesto Sergio Toledo-Redondo Jesús Fornieles |
| author_facet | Enrique A. Navarro Jorge A. Portí Alfonso Salinas Enrique Navarro-Modesto Sergio Toledo-Redondo Jesús Fornieles |
| author_sort | Enrique A. Navarro |
| collection | DOAJ |
| description | The word radome is a contraction of <i>radar</i> and <i>dome</i>. The function of radomes is to protect antennas from atmospheric agents. Radomes are closed structures that protect the antennas from environmental factors such as wind, rain, ice, sand, and ultraviolet rays, among others. The radomes are passive structures that introduce return losses, and whose proper design would relax the requirement of complex front-end elements such as amplifiers. The radome consists mostly in a thin dielectric curved shape cover and sometimes needs to be tuned using metal inserts to cancel the capacitive performance of the dielectric. Radomes are in the near field region of the antennas and a full wave analysis of the antenna with the radome is the best approach to analyze its performance. A major numerical problem is the full wave modeling of a large radome-antenna-array system, as optimization of the radome parameters minimize return losses. In the present work, the finite difference time domain (FDTD) combined with a genetic algorithm is used to find the optimal radome for a large radome-antenna-array system. FDTD uses general curvilinear coordinates and sub-cell features as a thin dielectric slab approach and a thin wire approach. Both approximations are generally required if a problem of practical electrical size is to be solved using a manageable number of cells and time steps in FDTD inside a repetitive optimization loop. These approaches are used in the full wave analysis of a large array of crossed dipoles covered with a thin and cylindrical dielectric radome. The radome dielectric has a thickness of ~λ/10 at its central operating frequency. To reduce return loss a thin helical wire is introduced in the radome, whose diameter is ~0.0017λ and the spacing between each turn is ~0.3λ. The genetic algorithm was implemented to find the best parameters to minimize return losses. The inclusion of a helical wire reduces return losses by ~10 dB, however some minor changes of radiation pattern could distort the performance of the whole radome-array-antenna system. A further analysis shows that desired specifications of the system are preserved. |
| first_indexed | 2024-03-10T07:44:29Z |
| format | Article |
| id | doaj.art-722aaf1f3ea7408e8b7f4dcc362bc1c2 |
| institution | Directory Open Access Journal |
| issn | 2079-9292 |
| language | English |
| last_indexed | 2024-03-10T07:44:29Z |
| publishDate | 2021-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Electronics |
| spelling | doaj.art-722aaf1f3ea7408e8b7f4dcc362bc1c22023-11-22T12:48:22ZengMDPI AGElectronics2079-92922021-09-011018226310.3390/electronics10182263Design & Optimization of Large Cylindrical Radomes with Subcell and Non-Orthogonal FDTD Meshes Combined with Genetic AlgorithmsEnrique A. Navarro0Jorge A. Portí1Alfonso Salinas2Enrique Navarro-Modesto3Sergio Toledo-Redondo4Jesús Fornieles5IRTIC Institute/ETSE, Universitat de València, Avd. Universitat, s/n, 46100 Burjassot, SpainDepartment of Applied Physics, University of Granada, Avd. Fuente Nueva, 16, 08019 Granada, SpainDepartment of Electromagnetism and Matter Physics, University of Granada, Avd. Fuente Nueva, 16, 08019 Granada, SpainEPS de Gandia, Universitat Politècnica de València, Calle Paranimf, 1, 46730 Gandia, SpainDepartment of Electromagnetism and Electronics, Campus de Espinardo, University of Murcia, 30100 Murcia, SpainDepartment of Electromagnetism and Matter Physics, University of Granada, Avd. Fuente Nueva, 16, 08019 Granada, SpainThe word radome is a contraction of <i>radar</i> and <i>dome</i>. The function of radomes is to protect antennas from atmospheric agents. Radomes are closed structures that protect the antennas from environmental factors such as wind, rain, ice, sand, and ultraviolet rays, among others. The radomes are passive structures that introduce return losses, and whose proper design would relax the requirement of complex front-end elements such as amplifiers. The radome consists mostly in a thin dielectric curved shape cover and sometimes needs to be tuned using metal inserts to cancel the capacitive performance of the dielectric. Radomes are in the near field region of the antennas and a full wave analysis of the antenna with the radome is the best approach to analyze its performance. A major numerical problem is the full wave modeling of a large radome-antenna-array system, as optimization of the radome parameters minimize return losses. In the present work, the finite difference time domain (FDTD) combined with a genetic algorithm is used to find the optimal radome for a large radome-antenna-array system. FDTD uses general curvilinear coordinates and sub-cell features as a thin dielectric slab approach and a thin wire approach. Both approximations are generally required if a problem of practical electrical size is to be solved using a manageable number of cells and time steps in FDTD inside a repetitive optimization loop. These approaches are used in the full wave analysis of a large array of crossed dipoles covered with a thin and cylindrical dielectric radome. The radome dielectric has a thickness of ~λ/10 at its central operating frequency. To reduce return loss a thin helical wire is introduced in the radome, whose diameter is ~0.0017λ and the spacing between each turn is ~0.3λ. The genetic algorithm was implemented to find the best parameters to minimize return losses. The inclusion of a helical wire reduces return losses by ~10 dB, however some minor changes of radiation pattern could distort the performance of the whole radome-array-antenna system. A further analysis shows that desired specifications of the system are preserved.https://www.mdpi.com/2079-9292/10/18/2263radomesFDTDsub-cell featurescurvilinear coordinatesGenetic Algorithms |
| spellingShingle | Enrique A. Navarro Jorge A. Portí Alfonso Salinas Enrique Navarro-Modesto Sergio Toledo-Redondo Jesús Fornieles Design & Optimization of Large Cylindrical Radomes with Subcell and Non-Orthogonal FDTD Meshes Combined with Genetic Algorithms Electronics radomes FDTD sub-cell features curvilinear coordinates Genetic Algorithms |
| title | Design & Optimization of Large Cylindrical Radomes with Subcell and Non-Orthogonal FDTD Meshes Combined with Genetic Algorithms |
| title_full | Design & Optimization of Large Cylindrical Radomes with Subcell and Non-Orthogonal FDTD Meshes Combined with Genetic Algorithms |
| title_fullStr | Design & Optimization of Large Cylindrical Radomes with Subcell and Non-Orthogonal FDTD Meshes Combined with Genetic Algorithms |
| title_full_unstemmed | Design & Optimization of Large Cylindrical Radomes with Subcell and Non-Orthogonal FDTD Meshes Combined with Genetic Algorithms |
| title_short | Design & Optimization of Large Cylindrical Radomes with Subcell and Non-Orthogonal FDTD Meshes Combined with Genetic Algorithms |
| title_sort | design optimization of large cylindrical radomes with subcell and non orthogonal fdtd meshes combined with genetic algorithms |
| topic | radomes FDTD sub-cell features curvilinear coordinates Genetic Algorithms |
| url | https://www.mdpi.com/2079-9292/10/18/2263 |
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