Microwave and Optical Technology Letters最新文献

{"title":"Wideband Endfire CP Log-Periodic Array Based on Compact Broadband OCP Water Helical Resonator","authors":"Rui Li,&nbsp;Jian Wei Pan,&nbsp;Hongbiao Chen,&nbsp;Zhenxin Hu,&nbsp;Duo-Long Wu,&nbsp;Songbo Cao,&nbsp;Qinxue Li","doi":"10.1002/mop.70295","DOIUrl":"https://doi.org/10.1002/mop.70295","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a wideband circularly polarized (CP) log-periodic antenna with endfire radiation based on normal-mode water helical resonator with omnidirectional circular polarization (OCP). The water resonator produces omnidirectional radiation of the horizontal and vertical electric field components, which are generated by the loop and short dipole components of the helix. There is a 90° phase difference between the two components, resulting in OCP radiation when the amplitudes of the two components are equal by simply adjusting the screw pitch of the helix. Owing to the larger aperture of a λ/2 water helical resonator compared to a λ/2 metallic helical resonator, a significantly improved radiation resistance of 48 Ω is achieved for the water helix (3.3 Ω for metallic helix). It is good for a wide impedance matching of the final array. The helical array is composed of 10 compact water helical elements obeying the logarithmic scaling of the operating frequency. A differential coupling-type feed line is employed to feed the array. Measured results show that a matching bandwidth from 635 to 1427 MHz (76.8%), an axial ratio bandwidth from 660 to 1275 MHz (63.6%), and a peak realized gain of 5.7 dBi are obtained. The proposed antenna has the potential to achieve a wider bandwidth by adding more elements, and can be applied to underwater communication or military communication with the advantage of high transparency.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647116","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":"Radio Frequency Identification Tag Based Flexible Angle Sensor for Dynamic Range Measurement","authors":"Xiao-Qing Yang,&nbsp;En-Kang Wu,&nbsp;Jun-Ge Liang","doi":"10.1002/mop.70303","DOIUrl":"https://doi.org/10.1002/mop.70303","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a flexible radio frequency (RF) sensor for measuring rotational angle. The sensor consists of a nested rectangular spiral inductor and two rectangular capacitors to form a radio frequency identification tag, which utilizes inductive coupling with an antenna for data transmission. The sensor has a wide dynamic detection range, accurately measuring rotation angles from 0° to 180°. Specifically, within the range of 0°–30°, the sensor exhibits exceptionally high sensitivity with 4.95 MHz/° and 0.093 dB/°. In the range of 90°–180°, frequency overlap occurs, so we take full advantage of the multi-parameter characterization of RF devices and jointly characterize the angle using the resonant frequency and return loss. The results were then subjected to quadratic regression fitting, which showed a high degree of agreement with the test results. Experiments have validated the sensor's performance, showing good reusability and a fast response speed. Compared to traditional passive angle sensors, this sensor combines RF sensing technology with flexible materials. The designed flexible wireless angle sensor is recommended for human joint measurement.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647221","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-Cost Ku-Band Planar Frequency-Phase Scanning Array Antenna for Low-Altitude Target Detection Applications","authors":"Ze Yu,&nbsp;Hao Fan,&nbsp;Chang Chen,&nbsp;Wei dong Chen,&nbsp;Xiang Zhang,&nbsp;Xiao lin Zhang","doi":"10.1002/mop.70304","DOIUrl":"https://doi.org/10.1002/mop.70304","url":null,"abstract":"<div>\u0000 \u0000 <p>This letter proposes a hybrid scanning regime phased array antenna that combines frequency and phase scanning to achieve multi-target detection and tracking in the 360° azimuthal (AZ) direction through mechanical and phase scanning, as well as elevation (EL) target detection by frequency scanning. The microstrip slow-wave line serves as a feed to the radiating patch, enabling frequency scanning. The strip line is coupled with energy through slots of different sizes, exciting the patch antennas, which can effectively enhance the impedance bandwidth of the line array. The Genetic Algorithm (GA) is used to design a low side lobe level (SLL) frequency-scanning line array, and metallic through-vias are utilized to reduce mutual coupling between line arrays, ensuring good active standing-wave radio (AVSWR) performance after two-dimensional phased array formation. The proposed frequency-phase scanning array antenna was fabricated and tested. The array consists of 48 series-fed line arrays arranged in the azimuth direction, all integrated onto a single PCB board measuring approximately 175 × 432 × 1.016 mm³ (9.7 × 24.2 × 0.06 λ³). This design offers advantages of low-profile, light-weight, and high-integration. And it can achieve ±45° phase scanning in the azimuth direction within a bandwidth of 15.7–17.7 GHz (12%), with SLL better than −26.1 dB. Additionally, it provides frequency scanning range greater than 21.4° and SLL better than −16.1 dB. The aperture efficiency ranges from 70% to 85%, and the maximum gain of the array reaches 35.9 dBi.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635442","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":"Temperature Stability of Optical Fiber Transmission Spectrum at Small Bending Radius","authors":"Yuhao Ma,&nbsp;Ran Bi,&nbsp;Xilong Guo,&nbsp;Lei Wang,&nbsp;Kan Chen,&nbsp;Xiaowu Shu","doi":"10.1002/mop.70288","DOIUrl":"https://doi.org/10.1002/mop.70288","url":null,"abstract":"<div>\u0000 \u0000 <p>This study leverages the principles of “Whispering Gallery Mode” (WGM) and bending loss to investigate the transmission spectrum of single-mode fibers under such conditions. Our experiments demonstrate that at a bending radius of 5.5 mm, with temperatures ranging from 25°C to 65°C at the bending point, the mean wavelength exhibits regular oscillations with an amplitude of 110.7 ppm, closely matching our simulation results of 113.9 ppm. By fine-tuning the material properties of different fiber sections, we can effectively mitigate these oscillations, thereby reducing sensing errors attributed to spectral modulation. This approach improves the transmission temperature stability of the fiber, which is of great significance for improving sensor performance and suppressing noise, and paves the way for more reliable and accurate fiber optic sensors.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635441","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 High-Gain, Broadband Filtering Antenna With High Sideband Suppression in Sub-6-GHz Band","authors":"Rinkee Chopra","doi":"10.1002/mop.70307","DOIUrl":"https://doi.org/10.1002/mop.70307","url":null,"abstract":"<div>\u0000 \u0000 <p>A low-cost, broadband filtering antenna is designed for high gain and high sideband suppression (SBS). The antenna is designed with a metallic fed patch and two electromagnetically coupled patches. A pair of longitudinally tapered and Γ-shaped slots is etched in a metallic fed patch to generate radiation nulls in the lower and upper frequency bands. Partial metallic walls are used to improve the antenna impedance matching. Its performance is investigated with systematic design evolution. The antenna prototype is fabricated to validate the results. The designed antenna provides 50% bandwidth for |S₁₁| ≤ −10 dB with a peak gain of 9.4 dBi, null depth, and SBS of more than 27 and 18.7 dB, respectively, in both bands. Cross-polarization (X-pol) and front-to-back ratio (FBR) of the filtering antenna are more than 20 and 18 dB, respectively, with an antenna size of 0.9<i>λ</i> × 0.57<i>λ</i> × 0.11<i>λ</i> at 2.05 GHz. The proposed filtenna is a good candidate for 5G and base station applications in sub-6-GHz frequency band.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635443","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 Broadband Circularly Polarized Antenna Using Transmissive Polarization Conversion Metasurface","authors":"Peng Wang,&nbsp;Hongwei Yuan,&nbsp;Xin Qu,&nbsp;Minquan Li,&nbsp;Yihong Qi,&nbsp;Zufeng Zhang,&nbsp;Yongkang Yuan,&nbsp;Fangcheng Huang","doi":"10.1002/mop.70296","DOIUrl":"https://doi.org/10.1002/mop.70296","url":null,"abstract":"<div>\u0000 \u0000 <p>With the rapid development of modern wireless communication technology, antennas, as a core component of the wireless communication system, have become a research focus. The axial ratio (AR) of an antenna is particularly critical to its overall performance. Increasing AR bandwidth can ensure circular polarization performance, enhance system compatibility, and improve anti-interference capabilities. This paper presents a design of a circularly polarized patch antenna based on metasurface technology. By incorporating a transmission-type polarization conversion metasurface, copper plates embedded vertically in the ground plane, and n-shaped parasitic patches, significant improvements in antenna performance are achieved. The tests show that the antenna achieves a 43.4% <i>S</i>₁₁ bandwidth within the frequency range of 4.94–7.68 GHz, and a 31.4% 3 dB AR bandwidth within the range of 4.83–6.43 GHz, demonstrating excellent performance. This study provides new technical support and design ideas for the field of wireless communication.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144615529","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":"Terahertz High-Power Sixteen-Way Power Combiner/Divider Using Combining Circular Waveguide Mode","authors":"Kaijun Song,&nbsp;Kezhou Pu,&nbsp;Qian Li,&nbsp;Hafiz Muhammad Talha Aslam,&nbsp;Yong Fan","doi":"10.1002/mop.70277","DOIUrl":"https://doi.org/10.1002/mop.70277","url":null,"abstract":"<div>\u0000 \u0000 <p>This study proposes a terahertz (THz) power combiner capable of handling multiple input pathways, employing an E-plane T-junction waveguide-mode converter to achieve the transition from the TE10 mode in a rectangular waveguide to the TE01 mode in a circular waveguide. To investigate its design, an equivalent-circuit model of the power-combining structure is developed, enabling an analysis of its geometric parameters and electrical characteristics. Furthermore, a comprehensive circuit model of the proposed combiner is presented. To verify the proposed design, a sixteen-way THz power combiner was constructed and tested. Simulation outcomes are consistent with experimental measurements. The device exhibits an average insertion loss of 1.6 dB and an input return loss greater than 15 dB over the 143-170 GHz frequency range, with a relative bandwidth of approximately 16%.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598223","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":"High-Frequency Selectivity Coaxial Multiplexer Using Chain Structure","authors":"Kaijun Song,&nbsp;Min Liu,&nbsp;Parama Kumarage Aresha Madhubhani,&nbsp;Yong Fan","doi":"10.1002/mop.70287","DOIUrl":"https://doi.org/10.1002/mop.70287","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a chain-structured coaxial multiplexer with high-frequency selectivity, which employs a coaxial resonant cavity structure. The cavity filter achieves ultrahigh frequency selectivity and excellent passband flatness by establishing a parameter mapping framework between the circuit model and full-wave electromagnetic simulation. The multiplexer is widely used as a passive component in existing mobile communication systems. Experimental results demonstrate that the multiplexer exhibits excellent performance, with insertion loss below 0.9 dB and return loss exceeding 20 dB across the 3, 4.8, 7.2, and 7.8 GHz frequency bands.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598220","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":"Performance Enhancement of a Two-Arm Monopole Antenna Using AMC for Modern Wireless Systems","authors":"Asmaa E. Farahat,&nbsp;Khalid. F. A. Hussein","doi":"10.1002/mop.70300","DOIUrl":"https://doi.org/10.1002/mop.70300","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a compact, low-profile, and wideband two-arm monopole antenna tailored to operate efficiently within the 3.7–7.3 GHz frequency spectrum. The monopole antenna is traditionally known for its omnidirectional radiation pattern and relatively low gain. To enhance its performance, this design integrates the monopole with an artificial magnetic conductor (AMC). The AMC is configured as a 3 × 3 array of specially modified square unit cells, covering a surface area of 9 × 9 cm. The antenna is positioned 1.7 cm above the AMC surface, a strategic placement that significantly enhances gain across the entire frequency range. In this configuration, the antenna's gain is markedly improved, increasing from an initial range of 1.5–3.25 dBi to an enhanced 4.6–8.5 dBi. Impedance matching is evaluated for both configurations, demonstrating consistent wideband performance. Analysis of the radiation patterns indicates that the monopole maintains an omnidirectional pattern without the AMC but shifts to more directive beams when the AMC is integrated. This combination results in a radiation efficiency of approximately 98% across the operating frequency band. Prototypes of the antenna and AMC were fabricated using the Rogers RO4003C substrate, which has a dielectric constant of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>ε</mi>\u0000 \u0000 <mi>r</mi>\u0000 </msub>\u0000 \u0000 <mo>=</mo>\u0000 \u0000 <mn>3.55</mn>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${varepsilon }_{r}=3.55$</annotation>\u0000 </semantics></math>, a loss tangent of tan δ = 0.0027, and a thickness of 1.52 mm. Experimental testing of these prototypes closely matched the simulation data, verifying the accuracy and effectiveness of the design. This study not only confirms the potential of the two-arm monopole enhanced with AMC for high-gain, wideband applications but also demonstrates its viability through rigorous simulation and practical experimentation. The results suggest that this antenna system is well-suited for modern communication systems that require efficient, wideband, and high-gain performance within the specified frequency range.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598222","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":"Analysis of C and S Trace Elements in Steel Using Orthogonal Preablation Dual-Pulse Laser Induced Breakdown Spectroscopy","authors":"Ming Liang,&nbsp;Yan Shao,&nbsp;Jinqi Dai,&nbsp;Jun Lu,&nbsp;Xun Gao","doi":"10.1002/mop.70299","DOIUrl":"https://doi.org/10.1002/mop.70299","url":null,"abstract":"<div>\u0000 \u0000 <p>The contents of nonmetallic elements such as C, S and P have an important influence on the hardness and strength of steel, so the detection the contents of these nonmetallic elements is critical task for the steel quality evaluation. In this paper, the C, S trace elements in steel are analyzed by using orthogonal preablation dual-pulse Laser induced breakdown spectroscopy (OP-DP-LIBS), and the spectral enhancements of C II 513.328 nm and S I 386.76 nm are observed as compared to SP-LIBS. The spectral intensity of C II 513.328 nm and S I 386.76 nm are increased with inter-pulse delay time and get maximum at delay time of 10 and 20 μs respectively, then decrease with inter-pulse delay time. Based on quantitative analysis of several trace elements in six alloy steel standard samples, correlation coefficient (<i>R</i>²) of C II 513.328 nm and S I 386.76 nm are all more than 0.9 and relative standard deviation (RSD) of two spectrum are all within 6%. The limit of detection (LOD) of C II 513.328 and S I 386.76 nm calculated are 209 and 7.32 ppm, respectively. It is demonstrated that detection precision and reliability can be enhanced by using OP-DP-LIBS, which means that nonmetal trace elements such as C and S in steel is become reality to detect within the range of 200–900 nm in air environment using OP-DP-LIBS technique.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 7","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144582234","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}