Microwave and Optical Technology Letters最新文献

{"title":"Thickness Measurement of Quartz and Analysis of Interface Roughness Effects Based on Terahertz Time-Domain Spectroscopy","authors":"Wenhui Yan,&nbsp;Hao Guan,&nbsp;Baiqiang Sun,&nbsp;Zhenwei Zhang","doi":"10.1002/mop.70691","DOIUrl":"https://doi.org/10.1002/mop.70691","url":null,"abstract":"<div>\u0000 \u0000 <p>Pulsed terahertz signal technology is increasingly being applied across various industries as an effective means of measuring material thickness. In terahertz time-domain spectroscopy systems, the presence of mixed noise affects the extraction of valid information and signal quality, making noise reduction essential for accurate thickness detection. Firstly, the system echoes are removed using double Gaussian inverse filtering, and then the system noise is removed using an adaptive variational mode decomposition method, which utilizes the minimum envelope entropy as the criterion, and through the sparrow search algorithm automatically optimizes the mode number and penalty factor to achieve adaptive and self-consistent noise removal. The terahertz signals of parallel-surface quartz specimens are reconstructed, and an automatic peak extraction algorithm is demonstrated. The influence of different surface roughness on reflective terahertz pulse signals and the correction parameters is quantitatively analyzed to achieve high-precision automated thickness detection.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2026-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148463148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D Printed X-Band Evanescent Mode Waveguide Filter Based on Pixelization Strategy","authors":"Jaroslav Zechmeister,&nbsp;Jaroslav Lacik","doi":"10.1002/mop.70653","DOIUrl":"https://doi.org/10.1002/mop.70653","url":null,"abstract":"<div>\u0000 \u0000 <p>A 3D-printed X-band evanescent mode waveguide filter based on a pixelization strategy is proposed in this paper. The uniqueness of the filter lies in the exploitation of the evanescent mode waveguide in conjunction with a 3D-printed dielectric pixelated structure. The crucial advantage of this approach is that the dielectric pixelated structure located in the waveguide does not require metal coating, significantly simplifying the fabrication process. The proposed filter is manufactured using fused deposition modeling (FDM) 3D print technology. Its measured transmission coefficient in the passband is below −1.67 dB, and the reflection coefficient is below −15 dB.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148386197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Multi-Stage Optimization Method for Designing Broadband Decoupling Matching Network","authors":"Kai Xu,&nbsp;Ya Wei Wang,&nbsp;Xu Chun Zhang,&nbsp;Wen Ye Ji,&nbsp;Tong Cai","doi":"10.1002/mop.70628","DOIUrl":"https://doi.org/10.1002/mop.70628","url":null,"abstract":"<div>\u0000 \u0000 <p>This article proposes an optimization method for broadband decoupling matching networks (DMNs) based on the simultaneous generation and alignment of multiple resonance points (RPs) and transmission zeros (TZs). The proposed DMN comprises cascaded simple H-shaped sub-networks, with only five structural parameters determined through stage-wise calculations. By decomposing the design process into multiple algorithmic stages, the method ensures stable generation of RPs and TZs, and can efficiently design broadband DMNs, reducing reliance on electromagnetic simulations. The effectiveness of this method was demonstrated using two antenna cases: a two-stage optimization of a dipole pair achieves a 15.32% overlapping bandwidth (|S₁₁ | &lt; −10 dB and |S₁₂ | &lt; −18 dB), while a three-stage optimization of a monopole pair attains 33.01% overlapping bandwidth (|S₁₁ | &lt; −10 dB and |S₁₂ | &lt; −15.6 dB).</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2026-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148386767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Ultra-Wideband Multimode Dual-Polarized Metasurface Antenna","authors":"Ruiqi Li,&nbsp;Xiang Zhang,&nbsp;Jingwen Wang,&nbsp;Weidong Chen,&nbsp;Chang Chen","doi":"10.1002/mop.70682","DOIUrl":"https://doi.org/10.1002/mop.70682","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents an ultra-wideband (UWB) dual-polarized metasurface antenna for applications such as sub-6 GHz 5G, Wi-Fi 6, C-band, and part of the X-band satellite and radar systems. Based on a slot-coupled microstrip antenna, the proposed design operates over 3.1–10.1 GHz (106% fractional bandwidth) through systematic optimization of the feeding slot, metasurface, and feed line, guided by surface-current and impedance-resonance analyses. The antenna provides a maximum realized gain of 12.0 dBi and an average in-band gain of 10.6 dBi, with an average efficiency of 90%. It also features a low profile of 0.04<span></span><math>\u0000 \u0000 <mrow>\u0000 <mi>λ</mi>\u0000 </mrow></math> at 3.1 GHz. With a dual-port, dual-linear-polarization configuration, the antenna exhibits high isolation (in-band <span></span><math>\u0000 \u0000 <mrow>\u0000 <mo>∣</mo>\u0000 \u0000 <msub>\u0000 <mi>S</mi>\u0000 \u0000 <mn>12</mn>\u0000 </msub>\u0000 \u0000 <mo>∣</mo>\u0000 \u0000 <mo>&lt;</mo>\u0000 \u0000 <mo>−</mo>\u0000 \u0000 <mn>29</mn>\u0000 </mrow></math> dB) and a low envelope correlation coefficient (ECC) below 0.0001, making it suitable for multiple-input multiple-output (MIMO) systems.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2026-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148322402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Wideband Magnetic Dipole Antenna With an Artificial Magnetic Conductor Reflector and Its Wide-Angle Scanning Phased Array","authors":"Honglin Zhang,&nbsp;Jiarong Wang,&nbsp;Zhijian Li,&nbsp;Zhijian Chen,&nbsp;Shaowei Liao","doi":"10.1002/mop.70642","DOIUrl":"https://doi.org/10.1002/mop.70642","url":null,"abstract":"<div>\u0000 \u0000 <p>Wideband and compact phased arrays are widely used in communication systems because of their wide-angle scanning capabilities. This paper presents a wideband wide-angle scanning phased array composed of eight compact magnetic dipoles and an artificial magnetic conductor (AMC) reflector. The magnetic dipoles, fed by tapered L-probes, achieve a fractional bandwidth of 45.3% (1.76–2.79 GHz) while maintaining a compact size of 0.188<i>λ</i>₀ × 0.188<i>λ</i>₀ at 2.25 GHz. The AMC reflector improves the front-to-back ratio (FBR) by 10 dB because it suppresses the backward radiation. The phased array is constructed with an element spacing of 0.42<i>λ</i>₀ to suppress grating lobes. Measured results demonstrate a maximum scanning range of ± 65° within a 34.8% fractional bandwidth (1.85–2.63 GHz), with a gain fluctuation less than 3 dB and a peak gain up to 13.2 dBi. The performance and compactness of the array ensure its suitability for wide-angle scanning applications.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148166921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Novel Microstrip-Valley Photonic Topological Waveguide for Robust Microwave Transmission","authors":"Yiyang Chen","doi":"10.1002/mop.70675","DOIUrl":"https://doi.org/10.1002/mop.70675","url":null,"abstract":"<div>\u0000 \u0000 <p>Topological insulators exhibit considerable immunity to path defects, and their lightweight advantage makes them easier to integrate compared to metallic waveguides and coaxial cables, offering a novel approach to support scattering-resistant transmission and transmission along bent paths. By adjusting the unit cell morphology of valley photonic crystals, this paper designs a <i>C</i>₃-symmetric microstrip valley photonic lattice based on a sector-shaped structure, which opens the degeneracy at the <i>K</i>(<i>K</i>′) points in the Brillouin zone and forms a topologically nontrivial photonic bandgap. Simulations and experiments demonstrate that this waveguide exhibits excellent filtering selectivity within the frequency range of 10.5–11.5 GHz, enabling unidirectional transmission and low-insertion-loss transmission of electromagnetic waves in the communication band. Compared with traditional metallic rectangular waveguides, the insertion loss variation caused by introducing a Z-shaped bending path is minimal, indicating remarkable robustness against path defects.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wideband n-Way Power Dividers Using Transformers for HF/VHF Applications","authors":"Da-Hai Ni,&nbsp;Lei Liu,&nbsp;Jie Chen,&nbsp;Zheng-Bin Wang","doi":"10.1002/mop.70655","DOIUrl":"https://doi.org/10.1002/mop.70655","url":null,"abstract":"<div>\u0000 \u0000 <p>In this letter, an <i>n</i>-way power divider based on ferrite transformers is presented for high-frequency (HF) and very-high-frequency (VHF) applications, where a novel circuit topology is proposed to realize wideband impedance matching. And a radial isolation network constructed by <i>n</i> resistors is introduced to improve the isolation, thereby avoid jumper resistors between output ports. The even-odd-mode analysis method is adopted to explore the mechanism of the proposed topology. Then, a wideband five-way power divider is designed to verify the validity of the proposed method and topology. The measured results demonstrate that this design exhibits excellent performance in the frequency band of 0.01-450 MHz. The return loss of the input port is better than 20 dB, the isolation between output ports is more than 23 dB, and the amplitude and phase imbalances are less than 0.2 dB and 1.7°, respectively.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graphene-Au-Cu-MXene Multilayer Metamaterial Plasmonic Biosensor With Machine Learning-Assisted Optimization for Label-Free THz Detection of Waterborne Bacterial Pathogens","authors":"Jacob Wekalao,&nbsp;Abdulkarem H. M. Almawgani,&nbsp;Mohammed M. Alammar,&nbsp;Adam R. H. Alhawari,&nbsp;Monir Abdullah,&nbsp;Amuthakkannan Rajakannu","doi":"10.1002/mop.70629","DOIUrl":"https://doi.org/10.1002/mop.70629","url":null,"abstract":"<div>\u0000 \u0000 <p>Detection of waterborne bacterial pathogens such as <i>Escherichia coli</i>, <i>Salmonella typhimurium</i>, and <i>Vibrio cholerae</i> requires methods that operate with high sensitivity and can be deployed outside laboratory settings. This study describes a multilayer metamaterial plasmonic biosensor operating in the terahertz frequency range for label-free refractive index sensing. The device uses a 4 × 4 periodic array of vertically stacked resonant nanostructures on a silicon substrate. The structure combines a gold Y-shaped nanoresonator, a copper circular cavity, a MXene square-ring resonator, and a graphene circular disc. This configuration supports strong field confinement, electrical tunability through graphene, and reduced reliance on noble metals.Finite element simulations in COMSOL Multiphysics quantify the dependence of absorption on incidence angle, graphene chemical potential, and resonator geometry. The optimized configuration uses a copper circular resonator diameter of 5500 nm, a MXene square-ring outer dimension of 2000 nm, and a gold Y-resonator arm width of 600 nm. Within a refractive index range of <i>n</i> = 1.33 to <i>n</i> = 1.3921, the device achieves a peak sensitivity of 0.751 THz/RIU and a figure of merit of 1.140 RIU⁻¹. The frequency response shows a linear relation with refractive index, with <i>R</i>² = 0.93337 across the evaluated material configurations. A regression-based surrogate model trained on the simulation dataset predicts device response with <i>R</i>² above 0.9992 and mean absolute percentage error below 0.2%. This model reduces the need for repeated full-wave simulations during design iterations. The results support the use of the proposed structure for label-free THz sensing of waterborne pathogens over relevant refractive index ranges.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 6","pages":""},"PeriodicalIF":1.1,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148324936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Compact Pattern- and Polarization-Reconfigurable Dielectric Resonator Antenna","authors":"Kunlong Zhao,&nbsp;Shiwen Lei,&nbsp;Menglong Chen,&nbsp;Xiaotong Sun,&nbsp;Wei Yang","doi":"10.1002/mop.70658","DOIUrl":"https://doi.org/10.1002/mop.70658","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 &lt;p&gt;In this letter, a compact pattern- and polarization-reconfigurable dielectric resonator antenna (DRA) based on complementary source is proposed. The antenna consists of a dielectric resonator (DR), four metallic rods, and two input ports. The DR operates in &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 \u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mstyle&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 \u0000 &lt;mtext&gt;TE&lt;/mtext&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;/mstyle&gt;\u0000 \u0000 &lt;mn&gt;111&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{TE}}_{111}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; mode, acting as a magnetic dipole, while the metallic rods function as electric dipoles, forming different complementary sources. By switching the excited modes of input ports and ON/OFF states of four p-i-n diodes, the antenna generates eight modes. These modes include broadside modes (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 \u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;θ&lt;/mi&gt;\u0000 \u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 \u0000 &lt;msup&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 \u0000 &lt;mo&gt;∘&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $theta ={0}^{circ }$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) with linear polarization at &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 \u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;φ&lt;/mi&gt;\u0000 \u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 \u0000 &lt;msup&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 \u0000 &lt;mo&gt;∘&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 \u0000 &lt;mo&gt;∕&lt;/mo&gt;\u0000 \u0000 &lt;mn&gt;4&lt;/mn&gt;\u0000 \u0000 &lt;msup&gt;\u0000 &lt;mn&gt;5&lt;/mn&gt;\u0000 \u0000 &lt;mo&gt;∘&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 \u0000 &lt;mo&gt;∕&lt;/mo&gt;\u0000 \u0000 &lt;mn&gt;9&lt;/mn&gt;\u0000 \u0000 &lt;msup&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 \u0000 &lt;mo&gt;∘&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 \u0000 &lt;mo&gt;∕&lt;/mo&gt;\u0000 \u0000 &lt;mn&gt;13&lt;/mn&gt;\u0000 \u0000 &lt;msup&gt;\u0000 &lt;mn&gt;5&lt;/mn&gt;\u0000 \u0000 &lt;mo&gt;∘&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;an","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced Frequency-Beam Scan by a Metamaterial ULWA With Multiple Lorentz Resonances","authors":"Yecheng Song,&nbsp;Lihui Lv,&nbsp;Min Du,&nbsp;Peiqing Wei,&nbsp;Yuyang Wu,&nbsp;Kuiwen Xu,&nbsp;Dexin Ye,&nbsp;Liang Peng","doi":"10.1002/mop.70657","DOIUrl":"https://doi.org/10.1002/mop.70657","url":null,"abstract":"<div>\u0000 \u0000 <p>Uniform or quasi-uniform leaky wave antennas (ULWAs) can realize fast beam scanning in space by varying the operating frequency. This scheme is enabled by the dispersive spectrum of the master waveguide (MWG). The dispersion of the MWG is crucial in determining the antenna's frequency beam scanning rate (FBSR), which is commonly low. To enhance the FBSR of a ULWA, we propose a metamaterial waveguide with double Lorentz resonances. We demonstrate that enhanced spectral dispersion of the MWG is formed between two distinct Lorentz oscillations through a superposition effect. By shifting either of the Lorentz oscillations, we can tune the MWG's spectral dispersion. As a result, the ULWA based on this highly dispersive MWG shows a controllable FBSR. We designed and fabricated a ULWA prototype in experiments. The measured FBSR of the ULWA can reach up to 19.8°/%, which is much higher than any previous designs. The proposed ULWA with enhanced FBSR can be used to promote novel applications, including fast target sensing, tracking, and imaging.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 6","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148174665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}