Microwave and Optical Technology Letters最新文献

{"title":"Compact Butler Matrix Using Lumped Elements","authors":"Edson R. Schlosser,&nbsp;Eduarda G. Peres,&nbsp;Natalia F. da Silva,&nbsp;Eduardo S. Sakomura,&nbsp;Marcos V. T. Heckler","doi":"10.1002/mop.70253","DOIUrl":"https://doi.org/10.1002/mop.70253","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper describes the design of a new compact circuit for Butler Matrix using few lumped elements to operate at 2.4 GHz. It is demonstrated that acceptable performance could be only achieved by proper electromagnetic modeling of the lumped components using metallic pads and resistor, inductor, and/or capacitor surfaces in Ansys HFSS, to allow compensating for parasitic and coupling effects. The input selection of the proposed architecture is realized digitally using an absorptive switch. The designed circuit has been used to feed a microstrip antenna array to demonstrate the beam switching capability. Very good agreement between the expected and measured results has been verified.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220017","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 Bidirectional Absorptive Common-Mode Filter Using Asynchronously Tuned and Corrugated Coupled-C Slot Resonators","authors":"Zhengyong Yu,&nbsp;Baozhu Li,&nbsp;Xun Jiang,&nbsp;Yongrong Shi,&nbsp;Wanchun Tang","doi":"10.1002/mop.70261","DOIUrl":"https://doi.org/10.1002/mop.70261","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper proposes a novel wideband bidirectional absorptive common-mode filter based on the modified coupled-C slot resonators. Each coupled-C slot resonator is constructed by etching two asynchronously tuned C-shaped slots with opposite direction. On this basis, single or two lumped resistors are added on the middle symmetric plane of coupled-C slot resonator to achieve unidirectional or bidirectional common-mode absorption. Furthermore, the corrugated slot stubs are introduced in coupled-C slot resonator to improve the common mode absorption performance. Subsequently, a bidirectional absorptive common-mode filter is proposed with wide absorption band and high absorption ratio by successively cascading unidirectional, bidirectional and unidirectional coupled-C slot resonators. As a demonstration, a prototype of the proposed common-mode filter has been fabricated and measured. The measured results show that the proposed common-mode filter could maintain good transmission of differential signals below 6.2 GHz. In addition, common-mode transmission and reflection coefficients could be kept less than −10 dB from 2.6 to 6.6 GHz simultaneously with 87% fractional bandwidth, demonstrating the good common-mode absorption performance.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220018","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":"Impedance Mismatch Approach to Design RF Power Amplifier With Harmonic Suppression","authors":"Saurabh Shukla,&nbsp;Soumava Mukherjee,&nbsp;Arani Ali Khan","doi":"10.1002/mop.70269","DOIUrl":"https://doi.org/10.1002/mop.70269","url":null,"abstract":"<div>\u0000 \u0000 <p>This letter presents the design of a PCB based RF power amplifier (PA) with improved harmonic suppression without the use of any external filter at the output. The proposed stepped impedance microstrip line input and output matching networks offer optimum impedance matching at the fundamental design frequency, whereas at harmonics, the impedances are of no match with the impedances required for higher harmonics power. The designed PA delivers 12.5 watt of CW power in Class-AB mode of operation at 2.45 GHz with measured power added efficiency (PAE) and drain efficiency (DE) of 62.7% and 63.5%, respectively. The first three harmonics of the PA are suppressed at least by 38.9 dBc as well. Measured Gain and input return loss of the amplifier are within 19 ± 0.6 dB and better than 12 dB, respectively, over 2.38–2.65 GHz.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220339","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-Polarized Frequency Selective Rasorber With Quasi-Elliptic Bandpass Response","authors":"Lingling Wang,&nbsp;Dong Han,&nbsp;Xuedao Wang,&nbsp;Min Zhu,&nbsp;Shaobin Liu,&nbsp;Yonggang Zhou","doi":"10.1002/mop.70272","DOIUrl":"https://doi.org/10.1002/mop.70272","url":null,"abstract":"<div>\u0000 \u0000 <p>In this paper, a dual-polarized frequency selective surface (FSS) capable of exhibiting a wide quasi-elliptic bandpass response is presented, analyzed, and then applied to the frequency selective rasorber (FSR) design. Three transmission poles (TPs) and two transmission zeros (TZs) can be achieved in the proposed FSS. The multimode resonances are responsible for the wide flat high-transmission passband and steep out-of-band rejection. The FSS is formed by two square metallic patches in the first and third layers, coupled with the quasi-spiral slot in the second layer. The equivalent circuit model (ECM) of the FSS is presented to analyze the resonance mechanism. Combining the FSS with a lossy layer loaded by lumped resistances, an FSR with the quasi-elliptic bandpass response can be obtained. The FSR indicates a wideband passband with low insertion loss, fast roll-off at the passband edges, and high transmission selectivity, which are verified by the simulation, equivalent circuit analyze and experiment.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220015","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 Quad-Band Antenna for Smartwatches With Optimized GPS, LTE, and Wi-Fi Band Support and Reduced Wrist Effects","authors":"Sami Ullah Khan,&nbsp;Muhummad Sulaiman Majeed,&nbsp;Sadiq Ullah,&nbsp;Hidayat Ullah,&nbsp;Usman Ali,&nbsp;Sajjad Rahim","doi":"10.1002/mop.70247","DOIUrl":"https://doi.org/10.1002/mop.70247","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a quad-band antenna for smartwatches, covering GPS, LTE, and Wi-Fi bands while minimizing wrist effects. It is a single-layer structure with a patch and ground plane printed on an FR-4 substrate. The antenna has a compact size of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mo>(</mo>\u0000 \u0000 <mn>0.172</mn>\u0000 \u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>o</mi>\u0000 </msub>\u0000 \u0000 <mo>×</mo>\u0000 \u0000 <mn>0.172</mn>\u0000 \u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>o</mi>\u0000 </msub>\u0000 \u0000 <mo>×</mo>\u0000 \u0000 <mn>0.006</mn>\u0000 \u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>o</mi>\u0000 </msub>\u0000 \u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $(0.172{lambda }_{o}times 0.172{lambda }_{o}times 0.006{lambda }_{o})$</annotation>\u0000 </semantics></math> mm³. It achieves 66% efficiency and −0.45 dBi gain in the GPS band, 2.74 dBi gain and 46% efficiency at 2.6 GHz, 2.76 dBi gain and 73% efficiency at 3.5 GHz in the LTE bands, and 67% efficiency and 2.46 dBi gain in the Wi-Fi band. The antenna exhibit −6 dB impedance bandwidths of 70, 561, 497, and 397 MHz for the GPS, LTE, and Wi-Fi bands, respectively. It maintains high efficiency, adequate gain and low SAR when mounted on a human wrist, making it a promising candidate for modern smartwatches.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144213752","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 Frequency- and Polarization-Reconfigurable Circular-Shaped Shared-Dipole Antenna","authors":"Binyun Yan,&nbsp;Yufan Shen,&nbsp;Xianjing Yuan,&nbsp;Weixing Sheng","doi":"10.1002/mop.70254","DOIUrl":"https://doi.org/10.1002/mop.70254","url":null,"abstract":"<div>\u0000 \u0000 <p>A compact frequency- and polarization-reconfigurable circular-shaped shared-dipole antenna is proposed. Arms of the shared dipole are connected by four p-i-n diodes, enabling frequency switching between L- and S-bands. The polarization reconfigurability is achieved by feeding the dual-polarized ports through a reconfigurable feed network. Based on the modified hybrid coupler with an impedance-matching network, the feed can perform quad-polarization transmission over a wide bandwidth. The equivalent circuit models of the antenna and the feed are both conducted for analysis. Since the transmitted signal can be canceled from one port to another in a shared dipole, high isolation better than 20 dB is achieved between the two ports. As a result, the circular polarization states share a wider bandwidth with the linear ones. A compact size of 0.49<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>H</mi>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${lambda }_{{rm{H}}}$</annotation>\u0000 </semantics></math> in diameter is achieved by reusing the dipole arms. Simulation and measurement results show that the antenna is capable of eight operating modes, switching between the L-band (1.8–1.95 GHz) and the S-band (2.17–2.5 GHz) with two orthogonal linear and two orthogonal circular polarization states.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206497","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":"Sequentially Rotated-Fed Patch Array Antenna for Off-Body Communication","authors":"Anurag Sahu,&nbsp;Ishika Gangwani,&nbsp;Arvind Kumar,&nbsp;Neeraj Rao","doi":"10.1002/mop.70256","DOIUrl":"https://doi.org/10.1002/mop.70256","url":null,"abstract":"<div>\u0000 \u0000 <p>This study presents a 2 × 2 sequentially rotated patch antenna array designed for a body area network (BAN) biotelemetry system operating in the unlicensed 5.8 GHz band. Circular polarization is achieved by truncating two diagonally opposite corners of the square patches, which excites two orthogonal modes within the antenna. This design enables the generation of circularly polarized radiation with enhanced characteristics in terms of bandwidth and gain. A prototype of the antenna array was manufactured and experimentally validated, demonstrating strong agreement between the simulated and measured results in terms of impedance bandwidth, axial ratio, gain, and radiation characteristics. The measured results show that the antenna operates from 5.65 to 5.91 GHz with a peak gain of 9.8 dBic. With its compact and low-profile design, the proposed antenna is well-suited for low-profile devices operating in the ISM band for biomedical applications.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144197290","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 Gradient Structure With Lattice Cores for Wide-Band and Wide-Angle Wave Transmission","authors":"Lixin Yang,&nbsp;Yanbin Li,&nbsp;Qiang Chen,&nbsp;Dahai Zhang,&nbsp;Qingguo Fei","doi":"10.1002/mop.70258","DOIUrl":"https://doi.org/10.1002/mop.70258","url":null,"abstract":"<div>\u0000 \u0000 <p>This study proposes a symmetric gradient lattice structure. The S-parameter inversion method is applied to investigate the equivalent electromagnetic properties of the lattice structure. Then, a methodology for the design of the symmetric gradient lattice structure is derived, whereby the complex design of a gradient lattice structure is transformed into a simple design of a multilayer impedance transformer. The 3D printing technology is adopted to fabricate samples to verify the effectiveness of the proposed method. Results show that the designed gradient lattice structure exhibits superior transmission performance, achieving a minimum transmission coefficient of −1 dB across a wide bandwidth of 5.8-24.8 GHz and a wide angular range of up to 60° for both TE and TM polarizations.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144190974","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":"Periodically Loaded Transmission Lines for Digital Signal Transmission in Homogeneous Media: Design and Analysis","authors":"Yokesh Venkatesh,&nbsp;Gulam Nabi Alsath Mohammed,&nbsp;Malathi Kanagasabai","doi":"10.1002/mop.70267","DOIUrl":"https://doi.org/10.1002/mop.70267","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper focuses on the design, fabrication and analysis of a periodically loaded transmission line (PLTL) within a homogenous medium. The proposed method aims to mitigate near-end crosstalk (NEXT) and far-end crosstalk (FEXT) improve the overall transmission performance for digital signal data transmission over a frequency range of 1 to 14 GHz. The periodic loading is designed to optimize the coupling ratios between capacitive and inductive components, leading to a more balanced and efficient microstrip transmission line. Unlike traditional microstrip configurations, the PLTLs in a homogeneous medium offer improved impedance matching and reduced signal distortion. This study employs full-wave simulations to analyze the performance of the proposed PLTLs and provides a comprehensive comparison with conventional microstrip transmission line design. The key parameters include insertion loss <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>|</mo>\u0000 <msub>\u0000 <mi>S</mi>\u0000 <mn>21</mn>\u0000 </msub>\u0000 <mo>|</mo>\u0000 </mrow>\u0000 <annotation> $|{S}_{21}|$</annotation>\u0000 </semantics></math>, near-end crosstalk <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>|</mo>\u0000 <msub>\u0000 <mi>S</mi>\u0000 <mn>31</mn>\u0000 </msub>\u0000 <mo>|</mo>\u0000 </mrow>\u0000 <annotation> $|{S}_{31}|$</annotation>\u0000 </semantics></math>, and far-end crosstalk <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>|</mo>\u0000 <msub>\u0000 <mi>S</mi>\u0000 <mn>41</mn>\u0000 </msub>\u0000 <mo>|</mo>\u0000 </mrow>\u0000 <annotation> $|{S}_{41}|$</annotation>\u0000 </semantics></math> are 0.535, 30.651, and 44.695 dB, respectively, evaluated to assess the defected microstrip structure (DMS) effectiveness in accommodating the digital signals. The experimental results are compared with the simulation outcomes to validate the accuracy of the proposed design.</p></div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144190976","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":"Additively Manufactured Reconfigurable Liquid Metal Monopole Antenna Using Reservoir-Based Feed System and Pneumatic Control","authors":"Connor S. Smith,&nbsp;Jimmy Nguyen,&nbsp;Simon B. Gott","doi":"10.1002/mop.70257","DOIUrl":"https://doi.org/10.1002/mop.70257","url":null,"abstract":"<div>\u0000 \u0000 <p>Reconfigurable antennas, which are capable of changing properties such as their resonant frequency, are becoming increasingly necessary for modern wireless communication systems. A variety of reconfigurable antennas have been developed, including those which use liquid metals as their conductors to adjust electrical length. However, monopole liquid metal-based antennas suffer from a variety of issues, such as the need for a liquid metal feed system that does not act as an undesired antenna. To overcome this issue, using reservoirs has proven useful, but current attempts have resulted in devices requiring either complex fabrication or control methods. In this study, an additively manufactured reconfigurable liquid metal monopole antenna is presented, which is fed by a reservoir of liquid metal and whose electrical length is controlled pneumatically using a syringe. The liquid metal used is eutectic gallium-indium, which is a nontoxic liquid metal often used in place of mercury. The antenna is characterized at liquid metal heights ranging from 30 to 65 mm, resulting in a −10 dB bandwidth of 1.27 GHz from 1.08 to 2.35 GHz. The calculated tuning range and tuning ratio are also found to be 74.1% and 2.18. A sensitivity to temperature is also shown, with an increase in temperature leading to an increase in resonant frequency. This study not only adds to the existing body of liquid metal monopole antennas found in the literature, but also demonstrates a relatively simple structure and control method.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 6","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144191104","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}