Microwave and Optical Technology Letters最新文献

{"title":"Design an Efficient Meta-Heuristic Chameleon Swarm Optimization Algorithm for Mutual Coupling Reduction in Slotted Fractal MIMO Antenna","authors":"Palniladevi Paulpandian,&nbsp;Sabapathi Thangavinayagam","doi":"10.1002/mop.70276","DOIUrl":"https://doi.org/10.1002/mop.70276","url":null,"abstract":"<div>\u0000 \u0000 <p>Multiple-Input and Multiple-Output have become fundamental components of wireless communication systems owing to their powerful beamforming capabilities and fast data rates. However, the compact design required for wireless systems leads to closely spaced antenna elements in multiple-input and multiple-output systems, resulting in mutual coupling that degrades total system performance. This study presents a decoupling method based on the Chameleon Swarm Optimization Algorithm to reduce mutual coupling between two densely packed Slotted Fractal multiple-input and multiple-output antenna, while maintaining low correlation between elements. Each element in the proposed antennas has a size of 26 × 35.5 × 3.2 mm³ and is made of FR4 substrate material with a center frequency of 4.55 GHz. The Envelope Correlation Coefficient is reduced to 0.03 by lowering the mutual coupling denoted by S₁₂ to less than −44 dB with the support of the Chameleon Swarm Optimization Algorithm and improved gain of 8.17 dBi. The developed MIMO antenna is optimized for sub-6 GHz 5 G applications, specifically covering bands n77, n78, and n79. The design is evaluated using MATLAB Software for antenna design and optimization process.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144323598","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 Highly Isolated Transparent 2 × 2 MIMO Antenna Based on Micro Metal Mesh Film","authors":"Abubaker Ahmed Elobied,&nbsp;Sung-Sil Cho,&nbsp;Yun-Seok Mun,&nbsp;Ic-Pyo Hong","doi":"10.1002/mop.70281","DOIUrl":"https://doi.org/10.1002/mop.70281","url":null,"abstract":"<div>\u0000 \u0000 <p>In this letter, we propose a novel highly isolated transparent 2 × 2 multiple-input multiple-output (MIMO) antenna based on a micro metal mesh film. The conductive material of the MIMO antenna comprises a micro-metal mesh structure made of thin copper strips, providing a sheet resistance of 0.05 Ω/sq and a transparency of 75%. The radiating patches of the MIMO antenna are fixed onto one side of an acrylic substrate, while the ground plane is attached to the opposite side. High isolation can be attained by arranging the radiating patches orthogonally and etching a novel cross-shaped slot on the ground. The transparent 2 × 2 MIMO antenna is successfully fabricated. The results of the fabricated antenna demonstrate a center frequency of 4.9 GHz, a bandwidth of 200 MHz, and a gain of 5 dBi. The isolation between the orthogonal antennas is 33 dB, while the parallel antennas exhibit an isolation of 44 dB. The correlation between the wireless channels is less than 0.003 over the bandwidth.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315017","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-Profile Broadband Gain Enhancement Fabry-Pérot Antenna With an Array Source and Vertical Metal Walls","authors":"Yangmeizi Fu,&nbsp;Zhiming Liu,&nbsp;Yiting Zeng,&nbsp;Hao Xu,&nbsp;Jiali Yan","doi":"10.1002/mop.70282","DOIUrl":"https://doi.org/10.1002/mop.70282","url":null,"abstract":"<div>\u0000 \u0000 <p>A low-profile broadband gain enhancement Fabry-Pérot (FP) antenna utilizing an array source and vertical metal walls is presented. The FP antenna consists of a source antenna and a partially reflective surface (PRS). The source antenna employs a 2 × 2 microstrip patch array to enhance the gain. The PRS comprises 10 × 10 PRS units, while the metal walls are strategically positioned within the cavity to optimize the radiation properties for the antenna. The prototyped FP antenna boasts a measured 10-dB impedance bandwidth of 9.59–10.57 GHz (9.7%), achieving a peak gain of 15.56 dBi at 10.09 GHz. The broadband, high-gain, and low-profile properties of the proposed antenna make it suitable for various high-integration communication systems. Both simulated and measured results confirm the validity of the proposed design.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308675","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 Asymmetric Cascode Doherty Power Amplifier With a Transformer-Based Combiner in 65-nm CMOS","authors":"Yuting Chen,&nbsp;Qing Guo,&nbsp;Yue Ma,&nbsp;Gang Wang,&nbsp;Bo Wu,&nbsp;Xianliang Wu","doi":"10.1002/mop.70260","DOIUrl":"https://doi.org/10.1002/mop.70260","url":null,"abstract":"<div>\u0000 \u0000 <p>In this study, we present a high-power back-off (PBO) efficiency asymmetric Doherty power amplifier (Doherty PA), featuring compact transformer-based input/output matching networks. The series output combiner, meticulously designed for asymmetric power ratio synthesis, integrates impedance inverters into the power combiner. This design significantly boosts power additional efficiency within a 9-dB PBO range. The integration of a quarter-wavelength phase compensation circuit and a quadrature power divider, both designed based on transformer structure, effectively minimizes the core chip area. Furthermore, the incorporation of neutralizing capacitor technology within the cascode structure has significantly enhanced gain and stability. The designed Doherty PA is manufactured by 65 nm CMOS technology, achieving 23.2 dBm saturated output power (<i>P</i>_sat) with 28.2% peak power added efficiency (PAE), and 22.4 dBm 1-dB output compression point (OP_1dB) at 38 GHz. The measured PAE at 9-dB PBO efficiency is 16.1%. These figures result in an efficiency enhancement ratio of 1.78 when compared to an ideal class-B PA.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144292000","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 Wideband Circularly Polarized High Isolation X-Band MIMO Dielectric Resonator Antenna","authors":"Ankita H. Harkare,&nbsp;Mahesh P. Abegaonkar","doi":"10.1002/mop.70275","DOIUrl":"https://doi.org/10.1002/mop.70275","url":null,"abstract":"<div>\u0000 \u0000 <p>This study paper presents a compact MIMO Dielectric Resonator Antenna designed for X-band communication. The antenna operates in the 8–15 GHz frequency range and exhibits circular polarization with a wideband characteristics. High isolation, below −20 dB, is achieved across the entire band by introducing a ground plane defect. The novel DRA consists of two stacked layers separated by an air gap to improve bandwidth. Circular polarization is achieved by feeding the dielectric resonators (DR) with orthogonal microstrip lines. This study explores the innovative integration of perforations into dielectric resonator antennas for MIMO applications. By investigating the effects of perforations on radiation characteristics and isolation properties, we aim to contribute to developing efficient and high-performance MIMO antenna systems, which are pivotal for meeting the ever-increasing demands of modern wireless communication technologies. Performance evaluation reveals a 72% complete overlap of 10 dB impedance bandwidth and 3 dB AR bandwidth. The proposed compact MIMO DRA offers the advantage of high isolation below −20 dB, a wide bandwidth of 72%, and circular polarization for X-band communication applications with complete overlap of 72%.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144292001","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 and Compact Tunable Reflection-Type Phase Shifter Based on Microstrip Slotline Coupler","authors":"Jianyu Ye,&nbsp;Jianbo Wang,&nbsp;Guang Hua","doi":"10.1002/mop.70255","DOIUrl":"https://doi.org/10.1002/mop.70255","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a broadband and compact <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mn>36</mn>\u0000 \u0000 <msup>\u0000 <mn>0</mn>\u0000 \u0000 <mo>∘</mo>\u0000 </msup>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $36{0}^{circ }$</annotation>\u0000 </semantics></math> tunable reflection-type phase shifter based on microstrip slotline coupler. The phase shifter consists of a microstrip slotline 3 dB coupler, along with two identical reflected loads made of variable capacitors and high-impedance transmission lines shorter than a quarter wavelength. This structure increases the bandwidth of reflection-type phase shifter and reduces the maximum insertion loss and the fluctuation of insertion loss. The measured return loss of the phase shifter shows a 47.2% bandwidth better than 10 dB, with center frequency insertion loss of 1.0∼2.7 dB and a maximum phase shift of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msup>\u0000 <mn>386.3</mn>\u0000 \u0000 <mo>∘</mo>\u0000 </msup>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${386.3}^{circ }$</annotation>\u0000 </semantics></math>. The phase shifter occupies an area of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mn>0.2</mn>\u0000 \u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>g</mi>\u0000 </msub>\u0000 \u0000 <mo>×</mo>\u0000 \u0000 <mn>0.4</mn>\u0000 \u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>g</mi>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $0.2{lambda }_{g}times 0.4{lambda }_{g}$</annotation>\u0000 </semantics></math> at 3.6 GHz.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273344","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":"ssDNA-Functionalized Optical Fiber SPR Sensor for Trace Dopamine Detection","authors":"Xiang Li,&nbsp;Rui-jie Tong,&nbsp;Yu Wang,&nbsp;Lu-yao Wang","doi":"10.1002/mop.70278","DOIUrl":"https://doi.org/10.1002/mop.70278","url":null,"abstract":"<div>\u0000 \u0000 <p>Dopamine, as a neurotransmitter, is essential for maintaining the function of the extrapyramidal nervous system. This article introduces an optical fiber sensor based on surface plasmon resonance (SPR) for detecting trace dopamine. The SPR effect is induced by an Au film coated on a plastic-cladding optical fiber. The specificity for dopamine is achieved through an aptamer, while graphene serves as a mediator between the gold-coated optical fibers and adapters. The sensor shows a linear sensitivity of 0.853 nm/log(M) over a dopamine concentration range of 10⁻¹¹ to 10⁻⁴ M, with a detection limit of 1 × 10⁻¹¹ M. Compared with existing dopamine detection methods, the proposed sensor exhibits a lower detection limit, a sufficiently wide linear range, and broad application prospects in biosensing.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264489","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 a Compact Wideband High-Efficiency Rectifier for Wireless Energy Harvesting","authors":"Fading Zhao,&nbsp;Yulin Zhong,&nbsp;Zhong Huang,&nbsp;Chu Chu,&nbsp;Mingfang Xia","doi":"10.1002/mop.70237","DOIUrl":"https://doi.org/10.1002/mop.70237","url":null,"abstract":"<div>\u0000 \u0000 <p>A novel high-efficiency microwave rectifier (MR) employing a parallel-connected single-stage voltage doubler (VD) to extend the operating bandwidth is proposed, which primarily consists of a coupled transmission line (CTL) and two parallel single-stage VD branches. The characteristics of the two parallel single-stage voltage doublers were analyzed theoretically and validated through simulation, demonstrating that the input impedance is insensitive to frequency variations by incorporating two inductors and a short tuning line. Making full use of this feature, a compact prototype with a simple matching network had been carefully designed, fabricated and measured. The experimental results show that the power conversion efficiency (PCE) is larger than 50% from 0.05 to 3.1 GHz, achieving a relative bandwidth of 193.6% at an input power of 10 dBm, in good agreement with simulation results. Additionally, the printed circuit board (PCB) size of the proposed rectifier can be as small as 21 × 11 mm^2.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264515","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":"GaN-on-SiC Broadband Driver Amplifier for C- and X-Band Applications","authors":"Abdullah Hannan,&nbsp;Erdem Aras,&nbsp;Armagan Gurdal,&nbsp;Emirhan Urfali,&nbsp;Salahuddin Zafar,&nbsp;Muhammad Imran Nawaz,&nbsp;Ekmel Ozbay","doi":"10.1002/mop.70259","DOIUrl":"https://doi.org/10.1002/mop.70259","url":null,"abstract":"<div>\u0000 \u0000 <p>A GaN-on-SiC-based broadband driver amplifier operating in the C- and X-bands from 5 to 12 GHz has been demonstrated. The MMIC has a typical small signal gain of 29.7 dB with a ±1.4 dB gain ripple. The input and output return losses are better than 10.5 and 8.8 dB, respectively. The average P<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mrow></mrow>\u0000 \u0000 <mi>s</mi>\u0000 </msub>\u0000 \u0000 <msub>\u0000 <mrow></mrow>\u0000 \u0000 <mi>a</mi>\u0000 </msub>\u0000 \u0000 <msub>\u0000 <mrow></mrow>\u0000 \u0000 <mi>t</mi>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${}_{s}{}_{a}{}_{t}$</annotation>\u0000 </semantics></math> is approximately 2.65 W with an OIP3 of 37.7 dBm, while the large signal gain is 22 dB. This design is distinguished by its low output power ripple and the low large signal gain fluctuations observed across the full frequency range of interest. Consistent load impedance matching at the output stage for the whole frequency range enabled an output power ripple less than ±1.1 dB and a large signal gain ripple less than ±0.6 dB at 10 dBm input power. This allowed for an output power density of at least 2.68 W/mm across the broad frequency range of 5–12 GHz. The typical power-added efficiency is 26.4%. To the best of the authors' knowledge, this DA design exhibits the best combination of gain, output power density, gain ripple, output power ripple and output return loss in this frequency band.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264491","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 Absorptive Frequency Selective Structure With Wide Transmission Band and Absorption Band","authors":"Jiahui Ye,&nbsp;Junbo Chen,&nbsp;Yuchang Chen,&nbsp;Weiliang Yu,&nbsp;Guo Qing Luo","doi":"10.1002/mop.70280","DOIUrl":"https://doi.org/10.1002/mop.70280","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper proposes a low-profile absorptive frequency-selective structure (AFSS) that exhibiting a wide absorption band and a wide low-insertion-loss transmission band. The AFSS is composed of two layers, separated by an air spacer layer. In the lossy layer, two meander-line loops loaded with lumped resistors are used to broaden the absorption band. Additionally, a frequency selective surface (FSS) based on a substrate-integrated waveguide (SIW) is proposed to achieve a wide transmission band. To reduce the insertion loss of the transmission band in the high frequency band, numerous circular holes are drilled in the substrate. Furthermore, two independent square patches are employed at the upper and bottom layers of the substrate to improve the performance stability under oblique incidence. The proposed bandpass AFSS achieves an absorption band from 2.67 to 8.58 GHz, with a fractional bandwidth of 105.07% and a 1-dB transmission band between 10.25 and 15.04 GHz, with a fractional bandwidth of 37.88%. A prototype is fabricated, assembled and tested, and the results exhibit a good agreement with the simulation results. And the thickness of the proposed AFSS is only 0.087λ_L, indicating that the design is very thin.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264490","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}