Iet Microwaves Antennas & Propagation最新文献

{"title":"Computation of monostatic RCS using adaptive sparsity pattern preconditioning with an MBF-MLFMM approach","authors":"Carlos Delgado,&nbsp;Eliseo García,&nbsp;Felipe Cátedra","doi":"10.1049/mia2.12531","DOIUrl":"https://doi.org/10.1049/mia2.12531","url":null,"abstract":"<p>This work presents a numerical technique for the analysis of the Radar Cross Section (RCS) of large targets combining macro-basis functions, the multilevel fast multipole method and the generation of near-field preconditioners, using an approximate inverse matrix where the sparsity pattern is dynamic and computed considering an upper memory threshold. In order to improve the scalability, a group of rows is computed using the same least squares matrix minimising the Frobenius norm of the error, rendering each row group problem independent from the rest. This approach is applied to large and realistic problems in the test cases included. The presented preconditioner can be used to optimise the convergence of complex problems with respect to the hardware resources available in each case while being transparent to the user.</p>","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 12","pages":"1094-1103"},"PeriodicalIF":1.1,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12531","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143253174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct design method for wideband quadruplet and higher-order bandpass filters with a pair of transmission zeros based on explicit design formulas","authors":"Juseop Lee,&nbsp;Hyunjong Choi,&nbsp;Jongheun Lee,&nbsp;Minhyup Song","doi":"10.1049/mia2.12530","DOIUrl":"https://doi.org/10.1049/mia2.12530","url":null,"abstract":"<p>This paper presents a direct design approach and explicit design formulas for a wideband quadruplet bandpass filter with a pair of transmission zeros. A filter can be designed based on a filter schematic composed of only transmission lines and a short-circuited coupled-line section. The electrical length of all lines including the coupled-line section is 90<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${}^{circ}$</annotation>\u0000 </semantics></math>. The impedances of all lines can be calculated by explicit design formulas given in terms of the normalised coupling values in a coupling matrix of a quadruplet filter, which differentiates this work from existing design approaches. A fourth-order filter example is illustrated for demonstrating the practicality of using the presented structure and design formulas. This paper also discusses the expansion of the presented direct design approach for higher-order filter designs.</p>","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 12","pages":"1084-1093"},"PeriodicalIF":1.1,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12530","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143252939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"General numerical solution of integral equation for long-range low-frequency groundwave propagation over irregular terrain","authors":"Dan-Dan Wang,&nbsp;Qi-Zirui Lu,&nbsp;Chao Han,&nbsp;Yun Fang,&nbsp;Yu-Rong Pu","doi":"10.1049/mia2.12536","DOIUrl":"https://doi.org/10.1049/mia2.12536","url":null,"abstract":"<p>The flexibility of the integral equation (IE) method is limited by the available numerical solutions with uniform-grid schemes. In this paper, a general numerical solution of the IE is presented to predict long-range low-frequency (LF) groundwave propagation over irregular terrain. The general numerical solution is re-derived with the aid of Legendre–Gauss quadrature and interpolation quadrature. The great advantage of the resulting algorithm is that it can freely use non-uniform grid sizes in the computation area without loss of accuracy. Numerical results in two surface types, including triangular mountain and actual terrain are used to demonstrate the performance of the presented algorithm. Furthermore, it is ascertained that the non-physical perturbations at long propagation ranges in the IE predictions are caused by the inherent uniform-grid schemes of the numerical solution rather than the several approximations in the derivation of the IE form.</p>","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 12","pages":"1148-1155"},"PeriodicalIF":1.1,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12536","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143253063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plane wave diffraction by a semi-infinite parallel-plate waveguide with partial material loading: The case of H polarisation","authors":"Tong Zhang,&nbsp;Kazuya Kobayashi","doi":"10.1049/mia2.12528","DOIUrl":"https://doi.org/10.1049/mia2.12528","url":null,"abstract":"<p>The analysis of diffraction by a semi-infinite parallel-plate waveguide with partial material loading is rigorously carried out using the Wiener–Hopf technique for the H-polarised plane wave incidence. In solving the Wiener–Hopf equations, the authors apply the Modified Residue Calculus Technique (MRCT) to achieve highly accurate solutions. The scattered field in real space is explicitly derived by performing the inverse Fourier transform of the solution in the transform domain. Within the waveguide, the scattered field is represented in terms of the waveguide TM modes, while the external field is asymptotically evaluated by applying the saddle-point method to yield a far field expression. The authors present representative numerical examples of the radar cross section for various physical parameters and discuss the far-field scattering characteristics in detail. Comparisons with the E-polarisation are also given.</p>","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 12","pages":"1055-1068"},"PeriodicalIF":1.1,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12528","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143252723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultra-broadband OAM generator of high-efficiency, high-purity vortex electromagnetic waves based on an ultrathin reflective Pancharatnam–Berry metasurface for the microwave band","authors":"Yongzhong Zhu,&nbsp;Fangxuan Zou,&nbsp;Wenxuan Xie,&nbsp;Kaiwei Zuo,&nbsp;Bao Xiong","doi":"10.1049/mia2.12513","DOIUrl":"https://doi.org/10.1049/mia2.12513","url":null,"abstract":"<p>In this paper, a new arc-shaped meta-atom like a fishbone controlled by Pancharatnam–Berry (PB) phase is designed for a microwave band, which can yield a high-purity vortex electromagnetic (EM) waves ranged from 10.63 to 26.86 GHz (relative bandwidth of 86.6%) with an efficiency of more than 90%. A single-beam metasurface with <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 </mrow>\u0000 <annotation> $m$</annotation>\u0000 </semantics></math> = +1, −2 and +3 modes is designed, respectively. Finally, a prototype with <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 </mrow>\u0000 <annotation> $m$</annotation>\u0000 </semantics></math> = −2 mode is manufactured in order to prove the feasibility of the designed metasurface. It shows that the experimental results are in good agreement with the ones of the simulation, which verified the excellent performance of the metasurface. The metasurface has a series of edges such as ultra-broadband, high efficiency, high purity and low profile compared to the conventional metasurfaces, which have strong practical applied value and significance for wireless communication.</p>","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 12","pages":"964-973"},"PeriodicalIF":1.1,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12513","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143248921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Doppler effects in UAV-to-vehicle multipath channels under 6D mobility","authors":"Junwei Bao,&nbsp;Zhuangzhuang Cui,&nbsp;Yang Miao,&nbsp;Qiuming Zhu,&nbsp;Kai Mao,&nbsp;Boyu Hua","doi":"10.1049/mia2.12527","DOIUrl":"https://doi.org/10.1049/mia2.12527","url":null,"abstract":"<p>Unmanned aerial vehicle (UAV) empowered vehicular networks are capable of providing flexible radio access, efficient data transmission, and secure driving operation. For these promising applications, the authors focus on channel modelling for UAV-to-vehicle (U2V) communications in this paper, which is the very first step for communication system design. Based on geometry and multi-dimensional mobility patterns, a geometry-based stochastic model framework for U2V communication is studied. Considering the practical scenario, multipath components (MPCs) are composed of a line-of-sight (LoS) path, a ground reflection (GR) path, and several random scattering (SC) paths. Specifically, the movement of a UAV in both three-dimensional (3D) translational and 3D rotational directions is considered as well as a ground vehicle capable of moving in arbitrary directions with varying velocities. Subsequently, the Doppler shift expressions for various paths and movements are presented individually, incorporating spatial angles. Comprehensive simulation results are examined, illustrating that six-dimensional (6D) motion exhibits varying effects with linear relative velocity, local angular velocity, and two types of spatial angles. Moreover, channel statistical properties such as temporal auto-correlation function (TCF) and Doppler power spectral density (PSD) are studied to show the consideration of 6D mobility is indispensable.</p>","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 12","pages":"1042-1054"},"PeriodicalIF":1.1,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12527","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143248920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and implementation of a novel wideband dual-polarised transmitarray antenna based on tightly coupled cross dipole cells","authors":"Yong Heng Zhao,&nbsp;Yin Li,&nbsp;Li Jun Jiang,&nbsp;Ping Li","doi":"10.1049/mia2.12525","DOIUrl":"https://doi.org/10.1049/mia2.12525","url":null,"abstract":"<p>A novel broadband dual-polarised transmitarray antenna (TA) utilising tightly coupled cross dipole cells is proposed in this work. The transmitarray cell using the tightly coupling wideband principle comprises two radiation patches designed as two orthogonal planar dipoles with four interdigital capacitors, two meandered parallel plate transmission lines, and a ground. Each cell has a square shape and a dimension of approximately 0.28 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 <mi>c</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${lambda }_{mathrm{c}}$</annotation>\u0000 </semantics></math> where <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 <mi>c</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${lambda }_{mathrm{c}}$</annotation>\u0000 </semantics></math> is the wavelength at central frequency 5.5 GHz. The transmitarray cell can achieve 475° phase shift at central frequency and transmission magnitude better than −2.5 dB within the working band. To verify the feasibility of this design, a tightly coupled dual-polarised transmitarray antenna (TCDPTA) is modelled and manufactured. The transmitarray aperture size is approximately 4.1 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 <mi>c</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${lambda }_{mathrm{c}}$</annotation>\u0000 </semantics></math> <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>×</mo>\u0000 </mrow>\u0000 <annotation> ${times} $</annotation>\u0000 </semantics></math> 4.1 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 <mi>c</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${lambda }_{mathrm{c}}$</annotation>\u0000 </semantics></math>. The simulation and measurement illustrate that the TCDPTA has stable and distortion-free main beams whose side lobe levels are generally below −10 dB in the band of 3.0–8.0 GHz. The measured gain at central frequency is 16.2 dBi and peak gain is 19 dBi at 7.5 GHz. The working bandwidth is 90.9% and 3 dB gain bandwidth is 66.7%. The measured cross-polarisation levels are below −15 dB at axial direction. This TA has potential applications for high-date-rate communication and high-revolution radar imaging systems at C-band.</p>","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 12","pages":"1011-1023"},"PeriodicalIF":1.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12525","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143248436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Guest editorial: Antenna integration and miniaturisation techniques","authors":"Liming Si,&nbsp;Yijing He,&nbsp;Tian Hong Loh","doi":"10.1049/mia2.12524","DOIUrl":"https://doi.org/10.1049/mia2.12524","url":null,"abstract":"&lt;p&gt;Antenna integration and miniaturisation techniques are crucial for maintaining the desired electrical and physical properties of antennas, while meeting the growing demands for reliable link performance and compact device designs for emerging wireless communications. This Special Issue presents recent advances in the theory, analysis, design, and application of antenna integration and miniaturisation. These techniques are enabling diverse novel designs and applications, propelling advancements in integrated circuits, and next-generation wireless communication systems rapidly. The papers in this Special Issue present the state-of-the-art contributions that address the challenges of design, fabrication, and performance enhancement for miniaturised and integrated antennas.&lt;/p&gt;&lt;p&gt;This Special Issue includes six high-quality papers, each presenting unique innovations in the field of antenna integration and miniaturisation. Thus, the overall submissions are of high quality, which marks the success of this Special Issue.&lt;/p&gt;&lt;p&gt;Ye et al. present a high-gain circularly polarised magneto-electric dipole antenna array with metallic radiating structures for millimetre-wave applications. This paper proposes a novel design of a magneto-electric dipole antenna array for millimetre-wave applications. The novel use of metallic radiating structures helps achieve high gain and circular polarisation, making the proposed design ideal for millimetre-wave communication systems.&lt;/p&gt;&lt;p&gt;Truong et al. introduce a method for designing an electrically small printed square loop antenna for closely spaced transmitter-receiver (Tx/Rx) systems. This paper demonstrates a compact antenna design, featuring a simple series combination of two lumped inductors and two interdigitated capacitors, providing inherent impedance matching without the need of an additional matching network. This proposed compact design method is highly relevant for modern and emerging wireless communication systems where space is often limited and confined.&lt;/p&gt;&lt;p&gt;Mao et al. propose a null-depth coordinated synthesis design approach for azimuthal null frequency scanning antennas (ANFSAs). A synthesis chart gauged by different null-depths is developed to determine the respective exciting amplitude and phase conditions for the principal and auxiliary radiators. This method provides a promising solution for achieving efficient frequency scanning with an in-band null-depth as high as −30 dB.&lt;/p&gt;&lt;p&gt;Choi et al. offer miniaturised ultra-wideband circular polarised Koch fractal crossed dipole array. The design incorporates a Koch fractal structure and an extended metallic sidewall to stabilise the axial ratio (AR) across a wide bandwidth. This innovative approach has significant potential for phased array applications in ultra-wideband (UWB) circularly polarised environments.&lt;/p&gt;&lt;p&gt;Xiong et al. present a novel millimetre-wave two-dimensional (2-D) wide-angle scanning phased array antenna based on decoupling surface","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 11","pages":"801-802"},"PeriodicalIF":1.1,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12524","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142737386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A hybrid equivalent circuit model and plane wave spectrum method for decoupling surface designs in multi-band shared-aperture antenna arrays","authors":"Xuan Deng,&nbsp;Yikai Chen,&nbsp;Shiwen Yang","doi":"10.1049/mia2.12526","DOIUrl":"https://doi.org/10.1049/mia2.12526","url":null,"abstract":"<p>Shared-aperture antenna arrays are attractive for 5G base stations, owing to their compact size and multi-band frequency coverage. Decoupling surfaces are effective for suppressing crossband mutual coupling. However, their designs typically rely on full-wave simulations of scattering parameters, which may not ensure a good radiation performance and is time-consuming. A systematic methodology based on the hybrid equivalent circuit model and plane wave spectrum method is proposed for decoupling surface designs. The decoupling surface is represented by its equivalent circuit and the spectral expression converts the electromagnetic field into a circuit problem. Both the scattering parameter and radiation pattern can be solved with the circuit, offering an efficient design method that ensures consistent radiation patterns between the model and full-wave simulations. A double-layer decoupling surface with wide stopbands, high transmission property, and sharp roll-off transition was realised. Furthermore, to reduce the overall profile height, the reflection phase of the decoupling surface was tuned. A triple-band shared-aperture base station antenna array was developed. Simulated and measured results demonstrate the array works properly in the 0.69–0.96 GHz, 1.7–2.7 GHz, and 3.3–3.8 GHz frequency bands with stable radiation patterns, and crossband mutual coupling is well suppressed, validating the effectiveness of the proposed methodology.</p>","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 12","pages":"1024-1041"},"PeriodicalIF":1.1,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12526","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143253716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A high efficiency wideband co-polarised metalens antenna","authors":"JiaJun Liang,&nbsp;Zhao Wu,&nbsp;Long Li,&nbsp;YanHu Huang","doi":"10.1049/mia2.12517","DOIUrl":"https://doi.org/10.1049/mia2.12517","url":null,"abstract":"<p>The traditional co-polarised metasurface achieves 360° phase coverage only at the resonant frequency but not full phase coverage across a wide bandwidth. This paper proposes a multilayer structure metasurface, which composes of five layers of metal patch and four layers of medium, forming the Fabry–Perry resonator, using the principle of the cancellation of two polarisation conversion, which can achieve a wideband efficient co-polarisation transmission. Based on the metasurface transmission phase principle, 360° phase coverage has been achieved by changing the geometric parameters of the intermediate metal patches. Through phase compensation arrangement, a metalens is designed using the proposed metasurface unit cell. At the same time, horn antenna is used as a feed to feed the metalens, which can significantly improve the gain of the antenna within a wideband. Simulated and measured results show that the proposed metalens antenna operates at 22–26 GHz, and the maximum measured gain of the metalens antenna reaches 24.16 dBi at 25 GHz, which is 10.85 dB higher than the horn antenna without metasurface compensation, showing good focusing performance. The proposed multilayer metasurface breaks the narrow band limit of the traditional stacked metasurface in principle, opening a way in the broadband metasurface design.</p>","PeriodicalId":13374,"journal":{"name":"Iet Microwaves Antennas & Propagation","volume":"18 11","pages":"803-809"},"PeriodicalIF":1.1,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mia2.12517","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142737472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}