ACES Publication Search
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| Title: | ACES Journal February 2025 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 1969 KB |
| Title: | ACES Journal February 2025 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 279 KB |
| Title: | ACES Journal February 2025 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 22390 KB |
| Title: | Higher-order Method of Moments Analysis of Waveguide with Irregular Cross-sections |
| Abstract: | Antennas fed by waveguides with irregular cross-sections are efficiently simulated through the hybridization of the mode-matching (MM) method and the higher-order method of moments (HOMoM). To obtain the waveguide modes required in theMMmethod, a 2-D finite element method (FEM) is utilized and combined with the hybrid MM/HOMoM method, which enables the proposed method to model irregular waveports. The accuracy and efficiency of the proposed method are demonstrated by simulating log-periodic antennas (LPAs) and an asymmetric single-ridge slot waveguide antenna. |
| Author(s): | N. Ding, Z. Lin, L. Yin, X. Zhao, Y. Zhang |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 1084 KB |
| Title: | A Spatial Modes Filtering FETD Method for 3-D Periodic Structures |
| Abstract: | A spatial modes filtering (SMF) finiteelement time-domain (FETD) method with periodic boundary condition (PBC) is proposed for efficiently analyzing the electromagnetic characteristics of 3-D periodic structures with partial fine structures. The system matrices of FETD become asymmetrical because of the introduction of PBC, which prevents the system eigenvalue analysis. By decomposing the system matrix into PBC-independent and PBC-related parts, the unstable spatial modes under the given large time step can be found and removed from the symmetrical PBCindependent system matrices. Then the system matrix equation and time marching of the SMF-FETD and SMF-FETD method based on local eigenvalue solution (LES-SMF-FETD) with PBC are obtained. Numerical results illustrate the efficiency and effectiveness of the SMF-FETD method with PBC based on non-uniform mesh for analyzing the transport properties of 3-D periodic structures. |
| Author(s): | Y. Wang, B. Wei, K. Fan, X. He, S. Zhao |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 548 KB |
| Title: | Electromagnetic Scattering from a Three-dimensional Object using Physics-informed Neural Network |
| Abstract: | Prediction of electromagnetic fields scattered from objects is of great significance in various fields. Traditional computational electromagnetic solvers, which are mesh-based, are expensive and timeconsuming. The deep learning technique becomes an alternative method of the prediction of scattered fields with high efficiency. However, the data-driven deep learning method requires a large data set and lacks robustness. For complicated scattering problems, the construction of a large training data set is a hard task. By considering physics-constraints, physics-informed neural networks (PINNs) can solve the partial differential equation (PDE) problem with a small data set and also provide a physical explanation. In this paper, the PINNs are employed to solve the scattering of a plane wave by a three-dimensional object with Maxwell’s equations being physical constraints. In the calculation, a sphere and an ellipsoid are taken as examples, and the effects of the network parameters (including the number of hidden layers, and the number of data sets) are mainly discussed. The results have practical applications in many fields such as radar detection, biomedical imaging, and satellite navigation. |
| Author(s): | Y. Zhang, R. Li, H. Tang, Z. Shi, B. Wei, S. Gong, L. Yang, B. Yan |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 2502 KB |
| Title: | Study on MPI-based Parallel FDTD Method of Moving Target Coated with Time-varying Plasma |
| Abstract: | Analyzing the electromagnetic (EM) scattering properties of high-speed moving objects is a hot research topic in recent years. However, EM calculations for high-speed moving targets always involve challenges of high computational complexity and low computational efficiency. In this paper, we integrate the Message Passing Interface (MPI) based parallel finite difference time domain (FDTD) method and Lorentz transformation to calculate the EM scattering of a moving metal sphere coated with time-varying plasma. Subsequently, by comparing the outcomes of the proposed Parallel FDTD approach with the serial computing results, the validity of the Parallel FDTD method is validated. Additionally, for a moving and time-varying plasma sheath coated object, the impacts of the time-varying parameters and plasma parameters on the EM scattering properties are investigated using the Parallel FDTD approach. The results indicated that the MPI-Based Parallel FDTD approach displays almost identical precision as the serial approach. Furthermore, the Parallel FDTD approach can enhance computation speed and significantly reduce the computation time. |
| Author(s): | H.-Y. Li, X.-M. Guo, Y. Bo, W. Chen, L.-X. Yang, Z.-X. Huang, J.-C. Wang, X.-J. Duan |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 6852 KB |
| Title: | Mie Scattering Properties of Simple RCS Objects and Applications |
| Abstract: | The requirement for advanced target recognition has facilitated the evolution of radar systems, enabling classification, recognition and identification of various types of objects. Numerous studies have focused on the accurate prediction of radar cross-section (RCS) for target identification. While the magnitude of the Mie scattering has been widely employed to enhance the likelihood for target detection, the proposed method based on the frequency spectrum of Mie scattering was presented for estimation of the size of the target. An accurate size of targets was quickly estimated using the frequency of the peak Mie scattering. The frequencies of Mie scattering are investigated using different radiuses of spheres and cylinders which directly indicate the size of objects. The peak magnitudes were acquired at 105∼485 MHz and 83∼398 MHz for spheres and cylinders, respectively, as the radiuses change from 0.1 m to 0.5 m. In addition, two aircraft-shaped models consisting of an ellipsoidal body, two wings and a stabilizer are used to obtain RCS scattering with various azimuth and elevation angles. Indoor RCS measurements with a metal sphere are presented in order to validate its effectiveness. |
| Author(s): | I. Kim, S.-G. Lee, J.-H. Lee |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 2110 KB |
| Title: | Design of 4×4 Multi-layer Butler-like Matrix with Flexible Phase Differences and Filtering Integration for 5G Applications |
| Abstract: | A universal topology for the filtering integrated Butler-like matrix (BLM) with flexible beam steering has been proposed based on the N/2 × N Butler matrix (BM). This structure is constructed on three-layer circuits, with compact size and no crossover owing to the path distribution. Besides, the filtering function has been integrated into the BLM by utilizing the multi-stage coupled lines. For validation, a 4×4 BLM operating at 4.9 GHz was designed and fabricated. Measured results reveal that the 4×4 BLM exhibits a working bandwidth of 18.4% and filtering integrated functions, with a compact size of 1.2×2.3 λg2. The measured scatting parameters and phase characteristics show great agreement with the simulated ones. |
| Author(s): | L. Ma, L. Wang, X. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 1214 KB |
| Title: | Discussion of the Transmission Efficiency of Quasi-optical Reflector Antenna Across Various Levels of Feeder Performance |
| Abstract: | For microwave radiometer calibration, higher main beam efficiency reduces interference from environmental brightness temperature (BT). A key challenge for high-frequency microwave sounders is achieving high main beam efficiency with limited mirror size. Although efficiency has improved to around 95-98%, there is still room for improvement. This study investigates the main beam efficiency of ground-based radiometer antenna systems, considering feeders with different radiating qualities and mirror conditions. A quasi-ellipsoidal mirror with feeders operating at multiple discrete frequencies is designed to optimize the optical path for microwave calibration. The key focus is transmission efficiency, which affects BT leakage. Numerical results for various feeders are compared - straight wall corrugated horns with 98.2% Gaussian content, dual-mode horns with 98.5%, curved wall corrugated horns with 99.8%, and ideal Gaussian beams - highlighting achievable transmission levels in different polarizations with different feeders. Design curves for the high main beam efficiency quasioptical reflector antenna system are provided. Such information is beneficial and of direct referencing value for practical radiometer reflector antenna designs. |
| Author(s): | H. Zhang, M. Jin |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 4388 KB |
| Title: | Study on Partial Coating Approach for Reducing Cavity Backscattering |
| Abstract: | Cavities are strong scattering parts for aircrafts, while coating the interior surface of cavities is a general approach for reducing cavity backscattering. In this paper, the discontinuous Galerkin (DG) method based on the self-dual integral equation (SDIE) is employed to efficiently simulate scattering from partially coated cavities. The distance sparse preconditioner (DSP) is applied to DG-SDIE for speeding up convergence instead of the conventional block-diagonal preconditioner (BDP). An efficient partial coating scheme is presented. The numerical results of straight cavity, Sshaped cavity and complex aircraft cavity demonstrate our coating scheme can achieve similar effect of reducing backscattering by using smaller coated interior surface regions. Useful conclusions about partially coating the cavity are summarized. |
| Author(s): | C.-B. Zhang, X.-W. Huang, X.-Q. Sheng |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 3456 KB |
| Title: | A Note on Matrix Decomposition for Synthetic Basis Functions Method in the Analysis of Periodic Structures |
| Abstract: | The synthetic basis functions method (SBFM) is discussed in this work and orthogonal triangle decomposition (QR decomposition) is adopted to extract independent items from solution space in the construction of synthetic functions. Just like singular value decomposition (SVD), accuracy of SBFM+QR improves with the growth of the number of synthetic functions. However, there is an interesting phenomenon for SBFM+QR: only one synthetic function is enough to get the same level of accuracy with method of moments (MoM) when a single body is concerned. Moreover, this feature can be further extended to periodic arrays. In other words, for periodic arrays, one synthetic function is enough to get high accuracy if SBFM+QR is adopted. This is meaningful for large-scale periodic arrays and may lead to benefits such as decreasing memory cost and improving efficiency. |
| Author(s): | Y. Xu, N. Hu, C. Liu, H. Ding, J. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 15818 KB |
| Title: | Conceptual Design and Preliminary Verification of a Double-bunch Switchyard for SXFEL |
| Abstract: | The Shanghai soft X-ray free-electron laser (SXFEL) is the first X-ray free-electron laser (FEL) user facility in China. To improve the utilization efficiency of the linear accelerator, SXFEL plans to upgrade to double-bunch mode with a bunch time separation of 100 ns and a maximum repetition rate of 50 Hz. A new conceptual beam distribution system is designed to separate the double beam bunch-by-bunch. Conceptual design and prototype implementation of a double-bunch separation system was implemented. The beam distribution system consists of four in-vacuum kicker magnets and one Lambertson septum magnet. This paper presents the design considerations and preliminary verification of a beam bunch distribution system. Distributed magnets and excitation power supply are introduced in detail. The relevant simulation and experimental results of the magnets and pulsed power supply are introduced also. |
| Author(s): | Y. Liu, J. Tong, S. Li, Y. Jiang, Q. Yuan, B. Liu |
| File Type: | Journal Paper |
| Issue: | Volume: 40 Number: 2 Year: 2025 |
| Download Link: | Click here to download PDF File Size: 4666 KB |