Microwave and Optical Technology Letters最新文献

{"title":"Effect of Thermal Noise on the Strain Gradient Sensor Using Cascaded Fiber Bragg Gratings","authors":"Fatma Ebrahim Mohamed Elnady,&nbsp;Ibrahim S. Tarrad,&nbsp;Khalid F. A. Hussein,&nbsp;Mohamed Yasin I. Afifi","doi":"10.1002/mop.70394","DOIUrl":"https://doi.org/10.1002/mop.70394","url":null,"abstract":"<div>\u0000 \u0000 <p>Understanding the distribution and gradient of longitudinal strain is essential for accurately assessing the structural integrity and mechanical behavior of materials and components under deformation. In this study, we investigate the impact of thermal noise on the performance of a strain gradient sensor based on fiber Bragg grating (FBG) technology. The proposed sensor architecture employs a series of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>M</mi>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $M$</annotation>\u0000 </semantics></math> cascaded uniform FBGs (UniFBGs), evenly spaced along a fiber-under-test (FUT), enabling spatially resolved strain measurement along the entire length of the structure. An analytical model is rigorously developed to characterize the sensor′s response to strain, incorporating the physical and optical behavior of the cascaded FBG array. The model accounts for wavelength shifts induced by strain and the corresponding changes in reflected spectra. Building on this foundation, we conduct a detailed numerical analysis of the sensor's signal-to-noise ratio (SNR), focusing specifically on the influence of thermal noise at the photodetection stage. The results provide valuable insights into the trade-offs between sensor resolution, reflectivity, interrogation configuration, and noise-induced limitations, contributing to the practical design and optimization of high-resolution distributed strain gradient sensing systems.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145012265","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 Low-Loss High-Frequency Transmission Line Structure for Ceramic Substrate","authors":"Pan Ren,&nbsp;Yaya Liang,&nbsp;Bo Peng,&nbsp;Chulin Wang,&nbsp;Cong Liu,&nbsp;Pingan Du","doi":"10.1002/mop.70360","DOIUrl":"https://doi.org/10.1002/mop.70360","url":null,"abstract":"<div>\u0000 \u0000 <p>An increase in signal frequency will lead to high transmission loss, the paper presents a novel high-frequency transmission line (HFTL) with low loss on the ceramic substrate. Based on the grounded coplanar waveguide (GCPW), the HFTL adds a parallel conductor under the center conductor strip, forming a two-layer structure interconnected by vias. It lowers the conductor's surface current density and surface impedance, significantly reducing losses. The transmission line structure is easy to integrate with RLC components and can be fabricated using existing HTCC processes. The characteristic impedance of the HFTL is derived to facilitate impedance matching, and the influence of geometric parameters on the characteristic impedance are also studied. The results from simulation and test show that the HFTL can achieve a 105.4% increase in bandwidth when the 3 dB bandwidth of GCPW is 31.2 GHz, and a 28.7% reduction in loss within the pass band compared to GCPW.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145012345","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":"Wide Gain Bandwidth Beam-Steering Transmitarray Utilizing Additive Manufacturing and Metal Machining for Satellite Communication","authors":"Javid Ahmad Ganie,&nbsp;Kushmanda Saurav","doi":"10.1002/mop.70386","DOIUrl":"https://doi.org/10.1002/mop.70386","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a beam-steering transmitarray antenna that leverages a hybrid fabrication approach to enhance bandwidth performance across the 24–30.5 GHz range. The core transmitarray element combines a metal-machined waveguide with an additively manufactured cross-shaped dielectric insert (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>ϵ</mi>\u0000 \u0000 <mi>r</mi>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${epsilon }_{r}$</annotation>\u0000 </semantics></math> = 2.2), achieving both structural precision and design flexibility. Each element measures approximately <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mn>0.9</mn>\u0000 \u0000 <mi>λ</mi>\u0000 <mspace></mspace>\u0000 \u0000 <mo>×</mo>\u0000 <mspace></mspace>\u0000 \u0000 <mn>0.9</mn>\u0000 \u0000 <mi>λ</mi>\u0000 <mspace></mspace>\u0000 \u0000 <mo>×</mo>\u0000 <mspace></mspace>\u0000 \u0000 <mn>1.8</mn>\u0000 \u0000 <mi>λ</mi>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $0.9lambda ,times ,0.9lambda ,times ,1.8lambda $</annotation>\u0000 </semantics></math> at 28 GHz. A wideband horn antenna mounted on a 3D-printed stand serves as the feed, with beam steering achieved through mechanical movement along the <i>x</i> and <i>y</i> axes, covering <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mo>±</mo>\u0000 \u0000 <mn>1</mn>\u0000 \u0000 <msup>\u0000 <mn>2</mn>\u0000 \u0000 <mo>∘</mo>\u0000 </msup>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $pm 1{2}^{circ }$</annotation>\u0000 </semantics></math> in both principal planes. The antenna attains a peak broadside gain of 22.4 dBi with only 1.3 dB steering loss, while its robust construction supports its use in harsh environments, making it well-suited for satellite communication applications.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145012093","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":"Design of Low-Temperature Co-Fired Ceramic-Based Miniaturized Filter With High Rejection for Super High-Frequency Band Applications","authors":"Zheyu Li,&nbsp;Weipeng Xuan,&nbsp;Rui Ding,&nbsp;Huaping Zhang,&nbsp;Hui Wang,&nbsp;Feng Gao,&nbsp;Hao Jin,&nbsp;Jikui Luo,&nbsp;Shurong Dong","doi":"10.1002/mop.70387","DOIUrl":"https://doi.org/10.1002/mop.70387","url":null,"abstract":"<div>\u0000 \u0000 <p>A super high-frequency (SHF) bandpass filter was designed and fabricated using low-temperature co-fired ceramic (LTCC) technology. To achieve miniaturization while suppressing undesired coupling effects that can generate spurious resonances and parasitic responses, a multilayer configuration was implemented, in which capacitive and inductive elements were allocated to specific layers and regions. Through utilizing the parasitic interactions between components, the number of discrete elements was reduced. Transmission zeros were introduced to enhance out-of-band (OoB) suppression through tailored routing of interconnecting lines, and mutual inductive coupling between inductors. The design was optimized using full-wave three-dimensional electromagnetic simulations. The fabricated LTCC filter exhibits a passband of 3.0–3.4 GHz with an OoB rejection exceeding 50 dB. Measured results are in good agreement with simulations, confirming the suitability of the proposed approach for SHF-band applications.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998952","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":"Ultra-Low Profile Broadband Printed Dipole Antenna With Gap and Vertical Asymmetric Printing for S-Band Applications","authors":"Jinxin Li,&nbsp;Feifan Gao,&nbsp;Zhu Liu,&nbsp;Pei Xiao,&nbsp;Gaosheng Li,&nbsp;William T. Joines,&nbsp;Shaolin Liao","doi":"10.1002/mop.70388","DOIUrl":"https://doi.org/10.1002/mop.70388","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper proposes a novel low-profile broadband printed antenna. It consists of two FR4 dielectric substrates, each printed on one side with different radiation units. The upper radiation element is a <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mo>⊔</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $bigsqcup $</annotation>\u0000 </semantics></math>-shaped bent dipole, while the lower is a <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mo>⊓</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $sqcap $</annotation>\u0000 </semantics></math>-shaped bent dipole. There is no overlap between the two in the vertical direction. Additionally, the shape of each arm is altered to enhance the radiation performance. A stepped impedance converter makes the connection between the feedline and the arms to improve the broadband characteristics of the antenna. A gap is left between the top and bottom plates to introduce an air layer to enhance the antenna radiation performance. The antenna has been subjected to manufacturing and testing, and the results obtained are consistent with those predicted by the simulation. The return loss of the proposed antenna is less than −10 dB in the frequency range of 2.69–3.22 GHz, and it exhibits an ultra-low profile.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998951","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":"Antenna Design Using an Enhanced Multi-Objective Artificial Hummingbird Algorithm Based on Tolerance Mechanism","authors":"Guan-Long Huang,&nbsp;Jin-Peng He,&nbsp;Peng-Fei Qin,&nbsp;Zi-Yu Pang,&nbsp;Xian-Hui He,&nbsp;Abdelhady Mahmoud,&nbsp;Jingtao Zeng,&nbsp;Hua Yang","doi":"10.1002/mop.70384","DOIUrl":"https://doi.org/10.1002/mop.70384","url":null,"abstract":"<div>\u0000 \u0000 <p>This letter presents a tolerance mechanism-based enhanced multi-objective artificial hummingbird algorithm (TM-EMOAHA) for antenna optimization. The proposed method introduces an improved Pareto non-dominated solution determination strategy with a tolerance mechanism to precisely define dominance relationships through objective prioritization. A hybrid perturbation strategy integrating polar coordinate transformation and objective-oriented guidance is developed to enhance global search capability. The algorithm's effectiveness is demonstrated through a series-fed patch antenna design case. Experimental results validate that compared with traditional multi-objective algorithms, the TM-EMOAHA obtains a series-fed patch antenna with higher gain characteristics and lower sidelobe.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144927542","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":"Multi-Objective Optimization Design of Dual-Polarized Broadband Frequency Selective Rasorber","authors":"Shumin Zhang,&nbsp;Zeyuan Sun,&nbsp;Tong Sun,&nbsp;Jinyu Zheng,&nbsp;Shifei Tao","doi":"10.1002/mop.70383","DOIUrl":"https://doi.org/10.1002/mop.70383","url":null,"abstract":"<div>\u0000 \u0000 <p>To address the challenges of prolonged design cycles, low efficiency, and excessive dependence on specialized expertise in the design of frequency selective rasorber (FSR), this letter presents a novel dual-polarized broadband FSR design based on multi-objective optimization algorithm. The proposed approach incorporates a surface patch discretization topology optimization method into two-dimensional FSR structural design. The discretized surface patches are encoded using a binary representation system and subsequently integrated with structural parameters into an intelligent optimization algorithm for topological configuration enhancement. To resolve the inherent conflict between structural dimensions and design principles in the “Absorption-Transmission”(“A-T”) type FSR, while simultaneously addressing the complex surface structure of lossy layers, we design a high-impedance resistive film-loaded dense metal patch coding structure combined with a second-order bandpass frequency selective surface (FSS). For effective optimization of the multi-variable, multi-objective FSR design problem, we implemented the NSGA-II enhanced with a simulated binary crossover operator (SBX) and an improved adaptive mutation mechanism. The optimized “A-T” type FSR demonstrates exceptional performance, achieving insertion loss less than 3 dB in the 6.88–12.94 GHz range and absorptivity exceeding 80% in the 2.18–6.14 GHz range.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144927413","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":"Quad-Band and Eight-Port MIMO Antenna for 5G Mobile Phones","authors":"Ce Shi,&nbsp;Yufa Sun","doi":"10.1002/mop.70381","DOIUrl":"https://doi.org/10.1002/mop.70381","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a MIMO antenna specifically designed for 5 G mobile communications. A multi-branch structure is utilized to enhance the operational frequency bandwidth of the antenna. However, multi-band antennas tend to increase inter-band interference, which presents a significant challenge in antenna design. To address this issue, a reverse-branch configuration is implemented to mitigate mutual coupling between the antenna elements. In contrast to most single-band mobile phone antennas, the proposed design achieves full coverage in both sub-6 GHz and millimeter-wave bands. The antenna can operate simultaneously in the 3.3–3.6, 4.8–5.0, 24.75–27.5, and 37–42.5 GHz bands. The isolation between antenna elements is better than –15 dB, the antenna efficiency ranges from 37% to 75%, the envelope correlation coefficient (ECC) is below 0.1, and the specific absorption rate (SAR) is less than 0.05 W/kg.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929774","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 Multifunctional Metasurface With Integrated Polarization Conversion and Lowinsertionloss Transmission","authors":"Dong Yu,&nbsp;Xiangkun Kong,&nbsp;Lingling Wang,&nbsp;Zhepeng Hou,&nbsp;Shaochun Zhou","doi":"10.1002/mop.70382","DOIUrl":"https://doi.org/10.1002/mop.70382","url":null,"abstract":"<div>\u0000 \u0000 <p>In this brief, a multifunctional metasurface combining frequency selective surface (FSS) and polarization converter is presented. A novel structure integrating anFSS and a polarization converter is introduced, which is cascaded with a low-frequency polarization converter to form a frequencyselective polarization converter (FSPC). The FSPC achieves a flat transmission window with an insertion loss of less than 1 dB in the frequency range of 8.7–10.7 GHz, while achieving polarization conversion bands (polarization conversion ratio &gt; 90%) across the 4.7–6.7 GHz and 13.6–6.3 GHz frequency ranges. The structure also demonstrates angular stability within a range of 30°. A four-port equivalent circuit model is employed to analyze the proposed FSPC. Furthermore, the checkerboard arrangement effectively reduces backward scattering within 4.7–15.4 GHz. A prototype was fabricated and experimentally validated, with test results showing good agreement with simulation results. The design shows promising application prospects in radar stealth systems.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144918672","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 Circular TE01 Mode Excitation for Air Drilling Using Novel Inline Rectangular TE10 Mode to Rectangular TE20 Mode Transition","authors":"Fangzhou Guo,&nbsp;Qingzhi Wu,&nbsp;Gao Li,&nbsp;Wenhe Xia","doi":"10.1002/mop.70370","DOIUrl":"https://doi.org/10.1002/mop.70370","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper proposes a circular TE₀₁ mode excitation for downhole microwave communication during air drilling, aiming to meet the critical requirements of preserving sufficient cross-sectional airflow area while maintaining a relatively short structural length. The excitation approach initiates by generating a rectangular TE₁₀ mode using a conventional probe. A novel inline transition structure is subsequently developed, employing a strategically positioned septum to achieve rectangular TE₁₀ to TE₂₀ mode conversion via field bisection into opposite phase components, while preserving maximum airflow capacity. The excitation further incorporates a compact three-section transition to facilitate efficient rectangular TE₂₀ to circular TE₀₁ mode conversion, reducing longitudinal dimension to mitigate drill pipe deformation effect. A cross-radial metal sheet (CRMS) configuration is implemented to effectively suppress spurious modes and enhance mode purity. Finally, a back-to-back prototype was fabricated and measured, showing a return loss better than 15 dB and an insertion loss lower than 1.3 dB from 6.13 to 6.27 GHz, demonstrating the performance of proposed method.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144915214","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}