Pub Date : 2024-03-25DOI: 10.13052/2023.aces.j.381105
Jiaguo Zhang, Huan Wei
In this paper, a fast Cross Coupling iterative Approach (CCIA) is proposed for studying the composite scattering of the layered rough surfaces with buried target, which uses forward backward method (FBM) to solve the electric field integral equations (EFIE) of the layered rough surface and bi-conjugate gradient method (BI-CG) to solve the EFIE of the target, and the interaction between the rough surface and the target is achieved by updating the excitation term. The algorithm is applied to calculate the composite scattering coefficients of the rough surface with a buried target, the results match with those of the traditional numerical algorithm MOM while the error can be reduced to 10−3 by 6 iterations, and the convergence speed and calculation accuracy meet the requirements. The composite scattering coefficients and Angular Correlation Function (ACF) amplitudes of layered rough surface and dielectric targets with different conditions are calculated, and the effects of various factors such as target size and burial depth on the composite scattering characteristics are discussed. It is found that the buried targets will have a great influence on the scattering characteristics, weakening or neglecting the coupling between them will lead to larger errors. Moreover, the results show that ACF can suppress scattering from rough surfaces well, making the scattering characteristics of the target more obvious, which is important for detecting underground targets.
{"title":"Composite Scattering Study of Layered Rough Surface withTarget based on CCIA","authors":"Jiaguo Zhang, Huan Wei","doi":"10.13052/2023.aces.j.381105","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381105","url":null,"abstract":"In this paper, a fast Cross Coupling iterative Approach (CCIA) is proposed for studying the composite scattering of the layered rough surfaces with buried target, which uses forward backward method (FBM) to solve the electric field integral equations (EFIE) of the layered rough surface and bi-conjugate gradient method (BI-CG) to solve the EFIE of the target, and the interaction between the rough surface and the target is achieved by updating the excitation term. The algorithm is applied to calculate the composite scattering coefficients of the rough surface with a buried target, the results match with those of the traditional numerical algorithm MOM while the error can be reduced to 10−3 by 6 iterations, and the convergence speed and calculation accuracy meet the requirements. The composite scattering coefficients and Angular Correlation Function (ACF) amplitudes of layered rough surface and dielectric targets with different conditions are calculated, and the effects of various factors such as target size and burial depth on the composite scattering characteristics are discussed. It is found that the buried targets will have a great influence on the scattering characteristics, weakening or neglecting the coupling between them will lead to larger errors. Moreover, the results show that ACF can suppress scattering from rough surfaces well, making the scattering characteristics of the target more obvious, which is important for detecting underground targets.","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":"111 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.13052/2023.aces.j.381108
Xiaoyan Zhang, Ziao Li, Aiyun Zhan, Y. Mei
A compact WLAN band-notched reconfigurable wideband antenna using two mushroom-like electromagnetic band-gap (EBG) structures is proposed in this paper. It is designed based on a dual wideband microstrip feed patch antenna with operating frequency bands of 2.2-3.7 GHz and 4.8-6 GHz. One of the EBG cells is positioned alongside the feed line, while the other EBG cell is laid on the back of the substrate. The patch or ground of the two EBG units are fed with a stronger current through a ground slot and a parasitic stub respectively, and the connections between the EBG structures and the antenna are controlled by loading a PIN diode with two 56 pF DC blocking capacitors. The advantage of this proposed design is that the antenna and the EBG unit can be designed independently. The proposed antenna has an overall size of 35×46×1.6 mm3. When testing the S11 of the antenna, the influence of the bias circuit on the antenna is also considered. The measured results show that the proposed antenna can generate two notched bands of 2.3-2.49 GHz and 5.11-5.51 GHz of WLAN, and the realized gain in the notch bands can be reduced to -2.65 dBi and -4.55 dBi, respectively, demonstrating its anti-interference characteristics, and can be applied in band notch broadband communication systems or anti-interference communication equipments such as unmanned aerial vehicles and radars.
{"title":"Design of a Reconfigurable Band-notched Wideband Antenna using EBG Structures","authors":"Xiaoyan Zhang, Ziao Li, Aiyun Zhan, Y. Mei","doi":"10.13052/2023.aces.j.381108","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381108","url":null,"abstract":"A compact WLAN band-notched reconfigurable wideband antenna using two mushroom-like electromagnetic band-gap (EBG) structures is proposed in this paper. It is designed based on a dual wideband microstrip feed patch antenna with operating frequency bands of 2.2-3.7 GHz and 4.8-6 GHz. One of the EBG cells is positioned alongside the feed line, while the other EBG cell is laid on the back of the substrate. The patch or ground of the two EBG units are fed with a stronger current through a ground slot and a parasitic stub respectively, and the connections between the EBG structures and the antenna are controlled by loading a PIN diode with two 56 pF DC blocking capacitors. The advantage of this proposed design is that the antenna and the EBG unit can be designed independently. The proposed antenna has an overall size of 35×46×1.6 mm3. When testing the S11 of the antenna, the influence of the bias circuit on the antenna is also considered. The measured results show that the proposed antenna can generate two notched bands of 2.3-2.49 GHz and 5.11-5.51 GHz of WLAN, and the realized gain in the notch bands can be reduced to -2.65 dBi and -4.55 dBi, respectively, demonstrating its anti-interference characteristics, and can be applied in band notch broadband communication systems or anti-interference communication equipments such as unmanned aerial vehicles and radars.","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":" 25","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.13052/2023.aces.j.381102
S. Barmada, P. D. Barba, A. Formisano, M. E. Mognaschi, M. Tucci
Learning from examples is the golden rule in the construction of behavioral models using neural networks (NN). When NN are trained to simulate physical equations, the tight enforcement of such laws is not guaranteed by the training process. In addition, there can be situations in which providing enough examples for a reliable training can be difficult, if not impossible. To alleviate these drawbacks of NN, recently a class of NN incorporating physical behavior has been proposed. Such NN are called “physics-informed neural networks” (PINN). In this contribution, their application to direct electromagnetic (EM) problems will be presented, and a formulation able to minimize an integral error will be introduced.
从实例中学习是使用神经网络（NN）构建行为模型的黄金法则。当训练神经网络模拟物理方程时，训练过程并不能保证严格执行这些法则。此外，在某些情况下，为可靠的训练提供足够的示例即使不是不可能，也是很困难的。为了缓解 NN 的这些缺点，最近有人提出了一类包含物理行为的 NN。这类神经网络被称为 "物理信息神经网络"（PINN）。本文将介绍其在直接电磁（EM）问题中的应用，并将介绍一种能够最小化积分误差的公式。
{"title":"Physics-informed Neural Networks for the Resolution of Analysis Problems in Electromagnetics","authors":"S. Barmada, P. D. Barba, A. Formisano, M. E. Mognaschi, M. Tucci","doi":"10.13052/2023.aces.j.381102","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381102","url":null,"abstract":"\u0000\u0000\u0000Learning from examples is the golden rule in the construction of behavioral models using neural networks (NN). When NN are trained to simulate physical equations, the tight enforcement of such laws is not guaranteed by the training process. In addition, there can be situations in which providing enough examples for a reliable training can be difficult, if not impossible. To alleviate these drawbacks of NN, recently a class of NN incorporating physical behavior has been proposed. Such NN are called “physics-informed neural networks” (PINN). In this contribution, their application to direct electromagnetic (EM) problems will be presented, and a formulation able to minimize an integral error will be introduced.\u0000\u0000\u0000","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":" 36","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.13052/2023.aces.j.381110
Siquan Zhang
An analytical model of an E-core driver-pickup coils probe located above a multilayer conductor containing a hidden cylindrical conductor is presented. The truncated region eigenfunction expansion (TREE) method is used to deal with the axial symmetry problem, and the closed-form final expression of the induced voltage in the pickup coil is derived. The changes of the induced voltage in the pickup coil due to the hidden cylindrical conductor are examined and calculated in Mathematica. Experiments and finite element simulations are performed and the results are compared with the analytical results, and they are in good agreement.
{"title":"Analytical Model of an E-core Driver-pickup Coils Probe Applied to Eddy Current Testing of Multilayer Conductor","authors":"Siquan Zhang","doi":"10.13052/2023.aces.j.381110","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381110","url":null,"abstract":"An analytical model of an E-core driver-pickup coils probe located above a multilayer conductor containing a hidden cylindrical conductor is presented. The truncated region eigenfunction expansion (TREE) method is used to deal with the axial symmetry problem, and the closed-form final expression of the induced voltage in the pickup coil is derived. The changes of the induced voltage in the pickup coil due to the hidden cylindrical conductor are examined and calculated in Mathematica. Experiments and finite element simulations are performed and the results are compared with the analytical results, and they are in good agreement.","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":" 70","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.13052/2023.aces.j.381107
Xiaoyan Zhang, Yuxu Hu, Aiyun Zhan
Generally, side slotting and directional techniques can improve the performance of a conventional Vivaldi antenna (CVA), but the optimal structure and distribution of slots and directors may be irregular or even complex, requiring significant manual effort, thus limiting the design possibilities. In this paper, a genetic algorithm (GA) is introduced to assist in designing and optimizing a new type of balanced side slotted Vivaldi antenna with director (SSVAD). The methods of artificial intelligence make the process of searching for the optimal structure of such a multi-objective and multi-dimensional problem simpler and more diverse. The GA-generated SSVAD antenna consists of a CVA and 34 slots with varying lengths, as well as 5 metal strips. It has a compact size of 38.2×49×0.8 mm3 (or 0.32λL×0.41λL×0.007λL, where λL is the lowest operating frequency of 2.48 GHz). The measured results show that the antenna has a peak gain >0 dBi over 2.48-10.88 GHz and >5 dBi over 4.6-10.88 GHz with S11<-10 dB standard, and exhibits directional characteristics at most of the operating frequencies. Since the measured results are basically consistent with the simulation ones, the effectiveness of the designed scheme has been proven.
{"title":"Design of a New Balanced Side Slotted Vivaldi Antenna with Director using Genetic Algorithm","authors":"Xiaoyan Zhang, Yuxu Hu, Aiyun Zhan","doi":"10.13052/2023.aces.j.381107","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381107","url":null,"abstract":"Generally, side slotting and directional techniques can improve the performance of a conventional Vivaldi antenna (CVA), but the optimal structure and distribution of slots and directors may be irregular or even complex, requiring significant manual effort, thus limiting the design possibilities. In this paper, a genetic algorithm (GA) is introduced to assist in designing and optimizing a new type of balanced side slotted Vivaldi antenna with director (SSVAD). The methods of artificial intelligence make the process of searching for the optimal structure of such a multi-objective and multi-dimensional problem simpler and more diverse. The GA-generated SSVAD antenna consists of a CVA and 34 slots with varying lengths, as well as 5 metal strips. It has a compact size of 38.2×49×0.8 mm3 (or 0.32λL×0.41λL×0.007λL, where λL is the lowest operating frequency of 2.48 GHz). The measured results show that the antenna has a peak gain >0 dBi over 2.48-10.88 GHz and >5 dBi over 4.6-10.88 GHz with S11<-10 dB standard, and exhibits directional characteristics at most of the operating frequencies. Since the measured results are basically consistent with the simulation ones, the effectiveness of the designed scheme has been proven.","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":" 393","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.13052/2023.aces.j.381103
Qin Nan, Chunhui Mou, Juan Chen
This paper presents the implementation of the parallel hybrid implicit-explicit finite-difference time-domain (HIE-FDTD) method using the Message Passing Interface (MPI) library. The method proves to be very effective in simulating large-scale three-dimensional electromagnetic problems with fine structures in one direction. For the decomposition of the computational volume in the HIE-FDTD method, an MPI Cartesian 2D topology is implemented, allowing arbitrary division of the volume in two directions. Derived data types provided in the MPI library are employed to optimize inter-process communication. High accuracy and efficiency are subsequently demonstrated through a numerical example of a frequency-selected surface (FSS). It shows that the proposed method is very suitable for parallel computing, and the parallel efficiency maintains above 80% for different numbers of processes.
{"title":"A Parallel 3-D HIE-FDTD Method using the MPI Library","authors":"Qin Nan, Chunhui Mou, Juan Chen","doi":"10.13052/2023.aces.j.381103","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381103","url":null,"abstract":"This paper presents the implementation of the parallel hybrid implicit-explicit finite-difference time-domain (HIE-FDTD) method using the Message Passing Interface (MPI) library. The method proves to be very effective in simulating large-scale three-dimensional electromagnetic problems with fine structures in one direction. For the decomposition of the computational volume in the HIE-FDTD method, an MPI Cartesian 2D topology is implemented, allowing arbitrary division of the volume in two directions. Derived data types provided in the MPI library are employed to optimize inter-process communication. High accuracy and efficiency are subsequently demonstrated through a numerical example of a frequency-selected surface (FSS). It shows that the proposed method is very suitable for parallel computing, and the parallel efficiency maintains above 80% for different numbers of processes.","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":" 369","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.13052/2023.aces.j.381109
Chenzhu Du, Huanchen Peng
A ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna using double Y-shaped decoupling structure with high isolation and triple notched-band is presented. The designed antenna composed of two orthogonally placed monopole elements, coplanar ground and double Y-shaped branch. The defected substrate structure is used to achieve miniaturization. By slotting successively C-shaped slot, semi-circular slot and rectangular slot on the radiation patch and the ground, achieved three notched bands at 3.5 GHz WiMAX, 5.25 GHz WLAN, and 7.5 GHz X-band. The proposed antenna can operate in range of 2.56-12 GHz with triple notched bands of 3.31-3.96 GHz, 4.58-5.67 GHz and 6.57-8.16 GHz. Considering all the results, it can be concluded that the antenna presented has a great performance in terms of good radiation, high isolation (>24 dB), a low level ECC (<0.01) and a high DG level (>9.99), which proves the presented antenna has good prospect in UWB-MIMO systems.
本文介绍了一种采用双 Y 形去耦结构的超宽带（UWB）多输入多输出（MIMO）天线，它具有高隔离度和三缺口带。所设计的天线由两个正交放置的单极元件、共面接地和双 Y 形分支组成。为了实现小型化，该天线采用了缺陷衬底结构。通过在辐射贴片和地面上依次开 C 形槽、半圆槽和矩形槽，实现了 3.5 GHz WiMAX、5.25 GHz WLAN 和 7.5 GHz X 波段的三个缺口频带。所提议的天线可在 2.56-12 GHz 范围内工作，并具有 3.31-3.96 GHz、4.58-5.67 GHz 和 6.57-8.16 GHz 三个陷波带。综合所有结果，可以得出结论：所提出的天线在良好辐射、高隔离度（>24 dB）、低水平 ECC（9.99）等方面具有出色的性能，这证明所提出的天线在 UWB-MIMO 系统中具有良好的前景。
{"title":"CPW-Fed UWB-MIMO Antenna with Triple-band Notched and High Isolation using Double Y-shaped Decoupling Structure","authors":"Chenzhu Du, Huanchen Peng","doi":"10.13052/2023.aces.j.381109","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381109","url":null,"abstract":"A ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna using double Y-shaped decoupling structure with high isolation and triple notched-band is presented. The designed antenna composed of two orthogonally placed monopole elements, coplanar ground and double Y-shaped branch. The defected substrate structure is used to achieve miniaturization. By slotting successively C-shaped slot, semi-circular slot and rectangular slot on the radiation patch and the ground, achieved three notched bands at 3.5 GHz WiMAX, 5.25 GHz WLAN, and 7.5 GHz X-band. The proposed antenna can operate in range of 2.56-12 GHz with triple notched bands of 3.31-3.96 GHz, 4.58-5.67 GHz and 6.57-8.16 GHz. Considering all the results, it can be concluded that the antenna presented has a great performance in terms of good radiation, high isolation (>24 dB), a low level ECC (<0.01) and a high DG level (>9.99), which proves the presented antenna has good prospect in UWB-MIMO systems.","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":" 53","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.13052/2023.aces.j.381106
Hongkun Ni, Hong Jiang, Xinbo Li, Qian Jia, Xiaohui Wang
The chassis based on the VPX bus standard structure has been widely applied to the fields of vehicle, missile, radar, etc. In this paper, we analyze the electromagnetic environment effect on VPX chassis via the CST software, and investigate the electromagnetic coupling characteristics of VPX chassis under 20 v/m plane wave radiation according to the RS103 test defined in the MIL-STD-461G standard. By simulation, we analyze the electromagnetic coupling paths of the VPX chassis, find the key positions of the electromagnetic protection such as the air intake, air outlet, trapdoor, and panel gaps, and we propose the electromagnetic protective measures for the weak parts of the VPX chassis. The electromagnetic shielding effectiveness before and after protection design is evaluated. Finally, the simulation results are verified by the experiments. It has guiding significance for the electromagnetic protection design of VPX chassis.
{"title":"Simulation Analysis of Electromagnetic Environment Effect and Shielding Effectiveness for VPX Chassis under Plane Wave Radiation","authors":"Hongkun Ni, Hong Jiang, Xinbo Li, Qian Jia, Xiaohui Wang","doi":"10.13052/2023.aces.j.381106","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381106","url":null,"abstract":"The chassis based on the VPX bus standard structure has been widely applied to the fields of vehicle, missile, radar, etc. In this paper, we analyze the electromagnetic environment effect on VPX chassis via the CST software, and investigate the electromagnetic coupling characteristics of VPX chassis under 20 v/m plane wave radiation according to the RS103 test defined in the MIL-STD-461G standard. By simulation, we analyze the electromagnetic coupling paths of the VPX chassis, find the key positions of the electromagnetic protection such as the air intake, air outlet, trapdoor, and panel gaps, and we propose the electromagnetic protective measures for the weak parts of the VPX chassis. The electromagnetic shielding effectiveness before and after protection design is evaluated. Finally, the simulation results are verified by the experiments. It has guiding significance for the electromagnetic protection design of VPX chassis.","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":"11 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-25DOI: 10.13052/2023.aces.j.381101
M. Marvasti, H. Boutayeb
This paper proposes an original and thorough analysis of the behavior of electromagnetic waves in the presence of moving bodies by using the finite difference time domain (FDTD) method. Movements are implemented by changing positions of the objects at each time step, through the classical FDTD time loop. This technique is suitable for non-relativistic speeds, thus for most encountered problems in antennas and propagation domain. The numerical aspects that need to be considered are studied. Then, different bodies in motion are examined: plane wave source with matching resistors, observation point, inclined partially reflecting surface (PRS), line source, and metallic cylinder illuminated by a plane wave. The results are compared with those of special relativity which are considered as the references. Some aspects of special relativity are present in the direct FDTD approach, such as the independence of the velocity of electromagnetic wave propagation with the speed of the source and Lorentz local time (with a different physical interpretation). It is shown that the amplitude of the electric field for a moving plane wave source does not increase with the speed of motion, if the impedance of the source is small. Moreover, for a moving scattering metallic wire, one can observe a phenomenon similar to shock waves.
{"title":"Analysis of Moving Bodies with a Direct Finite Difference Time Domain Method","authors":"M. Marvasti, H. Boutayeb","doi":"10.13052/2023.aces.j.381101","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381101","url":null,"abstract":"This paper proposes an original and thorough analysis of the behavior of electromagnetic waves in the presence of moving bodies by using the finite difference time domain (FDTD) method. Movements are implemented by changing positions of the objects at each time step, through the classical FDTD time loop. This technique is suitable for non-relativistic speeds, thus for most encountered problems in antennas and propagation domain. The numerical aspects that need to be considered are studied. Then, different bodies in motion are examined: plane wave source with matching resistors, observation point, inclined partially reflecting surface (PRS), line source, and metallic cylinder illuminated by a plane wave. The results are compared with those of special relativity which are considered as the references. Some aspects of special relativity are present in the direct FDTD approach, such as the independence of the velocity of electromagnetic wave propagation with the speed of the source and Lorentz local time (with a different physical interpretation). It is shown that the amplitude of the electric field for a moving plane wave source does not increase with the speed of motion, if the impedance of the source is small. Moreover, for a moving scattering metallic wire, one can observe a phenomenon similar to shock waves.","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":" 50","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.13052/2023.aces.j.381005
Tian-Long Yang, Xiao Zhang, Qiong‐Sen Wu, Tao Yuan
A miniaturized, wideband circularly polarized (CP) antenna based on coupled triangular patches is presented. Initially, two identical triangular patches with shorting pins are placed close to each other in a perpendicular orientation. Hence, a pair of orthogonal modes can be produced based on the coupled resonators. Under the characteristic mode analysis (CMA), it can be found that the 90∘ phase difference is achieved by modulating gap distance and shorting pins numbers. Both the shape of triangle patches and shorting pins contribute to the miniaturization. To further improve the AR bandwidth, a third patch is added to form a new mode. Thanks to the triple modes produced by the three patch elements, two AR minima are constructed to broaden the AR bandwidth. With this compact arrangement and shorting pins, a miniaturized wideband CP patch antenna with a 5.2% AR bandwidth is successfully implemented. The overall size of the antenna is merely 0.34λ0×0.33λ0×0.046λ0.
本文介绍了一种基于耦合三角形贴片的小型化宽带圆极化（CP）天线。起初，两个带短路引脚的相同三角形贴片以相互垂直的方向靠近放置。因此，基于耦合谐振器可以产生一对正交模式。根据特征模态分析（CMA），可以发现通过调节间隙距离和短路针数量可以实现 90∘的相位差。三角形贴片和短路针的形状都有助于实现微型化。为了进一步提高 AR 带宽，还增加了第三个贴片以形成新的模式。由于三个贴片元件产生的三重模式，构建了两个 AR 最小值，从而拓宽了 AR 带宽。通过这种紧凑的排列和短路引脚，成功实现了 AR 带宽为 5.2% 的小型化宽带 CP 贴片天线。天线的整体尺寸仅为 0.34λ0×0.33λ0×0.046λ0。
{"title":"Miniaturized Wideband Circularly Polarized Triangular Patch Antennas based on Characteristic Mode Analysis","authors":"Tian-Long Yang, Xiao Zhang, Qiong‐Sen Wu, Tao Yuan","doi":"10.13052/2023.aces.j.381005","DOIUrl":"https://doi.org/10.13052/2023.aces.j.381005","url":null,"abstract":"A miniaturized, wideband circularly polarized (CP) antenna based on coupled triangular patches is presented. Initially, two identical triangular patches with shorting pins are placed close to each other in a perpendicular orientation. Hence, a pair of orthogonal modes can be produced based on the coupled resonators. Under the characteristic mode analysis (CMA), it can be found that the 90∘ phase difference is achieved by modulating gap distance and shorting pins numbers. Both the shape of triangle patches and shorting pins contribute to the miniaturization. To further improve the AR bandwidth, a third patch is added to form a new mode. Thanks to the triple modes produced by the three patch elements, two AR minima are constructed to broaden the AR bandwidth. With this compact arrangement and shorting pins, a miniaturized wideband CP patch antenna with a 5.2% AR bandwidth is successfully implemented. The overall size of the antenna is merely 0.34λ0×0.33λ0×0.046λ0.","PeriodicalId":250668,"journal":{"name":"The Applied Computational Electromagnetics Society Journal (ACES)","volume":"19 75","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140237112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：