{"title":"A Broadband Magnetoelectric Dipole Reflectarray Antenna at Ku-Band","authors":"Weiwei Lv, Haibing Ding, Wenke Song, Jing Wang, Bin Zhang, Yuanzhe Luo, Qianzhong Xue","doi":"10.1002/mop.70130","DOIUrl":"https://doi.org/10.1002/mop.70130","url":null,"abstract":"<div>\u0000 \u0000 <p>In this letter, a broadband reflectarray (RA) antenna operating at Ku-band is proposed for wireless communication systems. Because the magnetoelectric (ME) dipole antennas have excellent low profile and wide impedance bandwidth performance, a multilayer wideband element is proposed based on a ME dipole and a true-time delay line. In addition, the elements achieve smooth and linear phase shift curves while maintaining high reflection amplitude over the operating frequency range. Next, employing the above element, a broadband linearly polarized RA antenna with a square aperture is designed and fabricated. The measured results show that the peak gain of the proposed antenna is 27.2 dBi, and the aperture efficiency is 45.3%. Besides, the 1 dB gain bandwidth is 27.5% from 14.4 to 18.8 GHz. The proposed RA antenna has the potential for broadband applications in wireless communication systems.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439122","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":"Dual-Band Rectifier Dedicated to 2.45 and 5.8 GHz Bands for Radiofrequency Energy Harvesting","authors":"Ognadon Assogba, Abdoul Karim Mbodji, Abdou Karim Farota, Abdou Karim Diallo, Arnaud Bréard, Yvan Duroc","doi":"10.1002/mop.70138","DOIUrl":"https://doi.org/10.1002/mop.70138","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents the design of a high-performance rectifier for radiofrequency energy harvesting (RF-EH) system. The proposed prototype operates in the two frequency bands, 2.45 and 5.8 GHz (part of the radio spectrum reserved internationally for industrial, scientific, and medical [ISM] purposes), which are widely present in the ambient environment, and enables energy to be recovered at low power levels to power loads of widely varying impedances. The designed rectifier is manufactured with dimensions of 0.31<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mn>0</mn>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${lambda }_{0}$</annotation>\u0000 </semantics></math> × 0.17<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mn>0</mn>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${lambda }_{0}$</annotation>\u0000 </semantics></math>, with <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mn>0</mn>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${lambda }_{0}$</annotation>\u0000 </semantics></math> the wavelength corresponding to the 2.45 GHz frequency. The rectifier is dual-band with a single series topology and good performance in terms of conversion efficiency at very low power levels (18% at −20 dBm at 2.45 GHz and 14% at −10 dBm at 5.8 GHz). The design methodology is detailed, and experimental results based on the prototype are presented and compared with the literature.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439124","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":"Low-Profile Wideband High-Gain Array Antenna With Quasi-Microstrip Feeding Network","authors":"Dinglun He, Shufang Li, Li Deng","doi":"10.1002/mop.70114","DOIUrl":"https://doi.org/10.1002/mop.70114","url":null,"abstract":"<div>\u0000 \u0000 <p>In contemporary communication systems, especially military radar systems, there is a significant demand for low-profile, wideband, high-gain antennas that can operate across the X-band (8–12 GHz). Despite numerous studies on X-band antennas, they are often characterized by limitations such as low gain, narrow bandwidth, or a high profile. This letter presents a monopole array antenna that combines the advantages of low-profile, wideband, and high-gain. And a parallel feeding network based on a quasi-microstrip structure is designed in this letter, which solves the problem of difficult feeding for this type of array. Through parameter optimization of the array antenna, its overall size is obtained as 76 mm × 63 mm × 5 mm, with an operational frequency range of 7.4–13.3 GHz and a relative bandwidth of 59%. Rigorous measurement of the array antenna's prototype has been conducted, revealing a high degree of congruence with simulation results. The measured results show that the antenna has a stable gain in the range of 13–14.3 dBi, and the highest measured aperture efficiency reached 47%. It is facile to fabricate and readily integrates with communication systems. This design also has a certain promotional effect on the research of wideband antennas.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438766","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}
Shuyi Chen, Hongmei Liu, Yang Wang, Chengcheng Zhao, Zhongbao Wang
{"title":"Miniaturized Wideband Unequal Four-Way Filtering Power Divider Using Asymmetric Three-Coupled Lines","authors":"Shuyi Chen, Hongmei Liu, Yang Wang, Chengcheng Zhao, Zhongbao Wang","doi":"10.1002/mop.70143","DOIUrl":"https://doi.org/10.1002/mop.70143","url":null,"abstract":"<div>\u0000 \u0000 <p>For the first time, a miniaturized wideband four-way unequal filtering power divider (FPD) based on asymmetric three-coupled lines (A-TCLs) is proposed. Two stepped-impedance resonators (SIR) are loaded on the A-TCL for enhancing the frequency selectivity and out-of-band rejection. Besides, two types of resistors are loaded for good output impedance matchings and isolations. Design equations are derived by combining the methods of even-odd mode decomposition and voltage-current analysis. For validation, a prototype with a power division ratio of 1.8:1:1:1.8 is designed. Measurements show that an overlapped bandwidth of more than 60% is obtained with low insertion loss, large out-of-band rejection and high frequency selectivity. In addition, the overall size is 0.43<i>λ</i><sub>g</sub> × 0.32<i>λ</i><sub>g</sub>, which is the smallest one in the state-of-the-art four-way FPDs.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439126","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}
Arpit Kumar Baranwal, Akhilesh Mohan, Nagendra P. Pathak
{"title":"Wideband Tapered Rod MIMO Antenna for W-Band Applications","authors":"Arpit Kumar Baranwal, Akhilesh Mohan, Nagendra P. Pathak","doi":"10.1002/mop.70145","DOIUrl":"https://doi.org/10.1002/mop.70145","url":null,"abstract":"<div>\u0000 \u0000 <p>In this paper, a wide band tapered rod two-element MIMO antenna system is designed using a perforated H-guide section for W-band applications. The antenna system comprises of a metallic housing and a perforated H-guide section with tapered input/output dielectric sections. The dielectric section is sandwiched between the two halves of the metallic housing. The designed MIMO antenna is fed by a pair of WR-10 rectangular waveguides. The perforations in the dielectric section not only provide the mechanical stability to the structure but also facilitate high inter-port isolation. The MIMO performance of the designed antenna system is calculated with reference to envelope correlation coefficient (ECC), diversity gain (DG), and channel capacity loss (CCL). These parameters are below the satisfactory range of 0.5, 10 dB, and 0.4 bit/s/Hz. High gain (> 12 dBi), high port-to-port isolation (> 28 dB), and end-fire radiation characteristics of the designed antenna system, make it a potential candidate for W-band communication systems.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439127","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":"Broadband Circularly Polarized Metasurface Antenna Based on Characteristic Mode Analysis","authors":"Juan Xu, Hui Pang, Jianping Zhao, Xiaohui Fang","doi":"10.1002/mop.70129","DOIUrl":"https://doi.org/10.1002/mop.70129","url":null,"abstract":"<div>\u0000 \u0000 <p>A broadband circularly polarized metasurface antenna is proposed. The initial metasurface structure is first diagonally chamfered and a rectangular slot is etched at the chamfer. The chamfering operation can cause an imbalance in the surface impedance of the hypersurface patch, and this imbalance creates a phase difference between the incident wave and the reflected wave, which is considered to be circularly polarized when the phase difference is close to 90° and the amplitudes of the two are equal. Analyze the metasurface structure after chamfering using the characteristic mode theory (CMT), further optimize it based on the obtained characteristic mode analysis results, and analyze it again using the characteristic mode. Finally, two target modes with a phase difference close to 90° were formed. The two characteristic modes are successfully excited by microstrip slot-coupled feeding structure to achieve circularly polarized radiation of the antenna. Finally, the antenna is fabricated and measured. Based on the measured results, it can be observed that the antenna has 35.4% −10 dB impedance bandwidth, and 17% 3 dB axial ratio bandwidth, and the antenna simulated and measured results match.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438765","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":"Single-Layer Dual-Polarized Millimeter Wave Slot Antenna Using Nested Radiators Under Four Resonance Modes","authors":"Li Jiawang, Lei Xiang, Yitong Shi, Huimin Liu","doi":"10.1002/mop.70132","DOIUrl":"https://doi.org/10.1002/mop.70132","url":null,"abstract":"<div>\u0000 \u0000 <p>This letter proposes a novel single-layer dual-polarized (DP) millimeter wave (mmWave) low-profile antenna. This antenna is based on a circular substrate integrated waveguide (SIW) resonant cavity. Two different resonant cavities are created by incorporating via fences internally: a conventional circular resonant cavity and a circular ring resonant cavity. The bandwidth is expanded by introducing a central via in the internal resonant cavity, which generates the <i>TM</i><sub>010</sub> and <i>TM</i><sub>110</sub> resonant modes. On the other hand, the external annular resonant cavity introduces the <i>TM</i><sub>410</sub> and <i>TM</i><sub>510</sub> resonant modes by carefully adjusting the size of the radiation slot. The radiation slots within the external annular resonant cavity and the inner circular resonant cavity are positioned orthogonally, enabling dual-polarized (DP) operation. It is shown that the DP antenna can achieve the measured −10 dB impedance bandwidths (FBW) of 11.82% (26.26–29.56 GHz) and 11.15% (26.09–29.17 GHz) for port 1 and port 2, respectively. The antenna features stable radiation patterns with an average gain of 5.1 dBi and a high isolation exceeding 20 dB within the passband. The antenna exhibits a single-layer structure, low profile, high-isolation, and low-cost advantages, which can be a good candidate for 5G mmWave indoor applications.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439105","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}
Wei Liu, Youlun Ju, Tongyu Dai, Qiang Liu, Chao Liu
{"title":"A Compact 2.05 μm MOPA Laser With SLM Operation","authors":"Wei Liu, Youlun Ju, Tongyu Dai, Qiang Liu, Chao Liu","doi":"10.1002/mop.70142","DOIUrl":"https://doi.org/10.1002/mop.70142","url":null,"abstract":"<div>\u0000 \u0000 <p>We present a single longitudinal mode Ho:YLF MOPA laser operating at 2050.7 nm by utilizing the Fabry–Perot etalon method to construct a compact SLM seed laser and employing Tm-doped fiber as the amplifier. With an output power of 336 mW generated by the seed laser, the maximum output power of 13.1 W for the single longitudinal mode MOPA laser was recorded at a pump power of 88.7 W. A peak slope efficiency of 26.9% was achieved when the pump power exceeded 58.7 W. To our knowledge, this is the first report of utilizing Tm-doped fiber to amplify the SLM operation of Ho:YLF laser.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431524","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}
Huaiwei Wang, Gang Zhang, Jie Tian, Kam-Weng Tam, Wanchun Tang, Jiquan Yang, Jinlong Zhang, Na Li
{"title":"Balanced-to-Single-Ended Out-of-Phase Filtering Power Divider With Continuously Tunable Center Frequency and Bandwidth Using Compact Patch Resonators","authors":"Huaiwei Wang, Gang Zhang, Jie Tian, Kam-Weng Tam, Wanchun Tang, Jiquan Yang, Jinlong Zhang, Na Li","doi":"10.1002/mop.70098","DOIUrl":"https://doi.org/10.1002/mop.70098","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a novel compact balanced-to-single-ended out-of-phase filtering power divide with continuously tunable center frequency and bandwidth. By introducing a T-shaped slot on the isosceles right triangle patch resonator to perturb the TM<sub>10</sub> mode and exploring varactors-loaded stubs, a new tunable miniaturized patch resonator is created. The proposed filter comprised three new tunable patch resonators connected by back-to-back varactors to adjust bandwidth in between. By studying the electric field distribution of the odd mode TM<sub>10</sub> and grounded isolation resistors, the wished out-of-phase output signal and good port-to-port isolation can be generated. Based on such a simple structure, a balanced-to-single-ended out-of-phase filtering power with tunable bandwidth is designed and realized with a center frequency tuning range covering from 1.60 to 1.95 GHz (19.7%) and 3-dB bandwidth tuning range covering from 265 to 328 MHz at 1.90 GHz.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423754","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}
Jie Zheng, Mengyu Zong, Kun Ye, Xiaoyue Feng, Jingjing Liu, Jie Liu, Danhua Liu, Zhongyuan Liu
{"title":"Monolayer WSe2 Film as Saturable Absorbers for Mid-Infrared Passive Q-Switching","authors":"Jie Zheng, Mengyu Zong, Kun Ye, Xiaoyue Feng, Jingjing Liu, Jie Liu, Danhua Liu, Zhongyuan Liu","doi":"10.1002/mop.70119","DOIUrl":"https://doi.org/10.1002/mop.70119","url":null,"abstract":"<div>\u0000 \u0000 <p>The monolayer WSe<sub>2</sub> material was utilized for a saturable absorber to create a 2.7 μm passively Q-switched pulse laser. The maximal single pulse energy was 2.75 µJ, and the highest peak power was measured approximately 2.53 W. As far as we know, this is the first instance of monolayer WSe<sub>2</sub> being used for passive Q-switching operation in mid-infrared. The results provide favorable evidence for monolayer WSe<sub>2</sub> as a mid-infrared Q-switcher and show the promise of monolayer two-dimensional materials for ultrafast pulsed laser applications.</p></div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 2","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143248412","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}