Microwave and Optical Technology Letters最新文献

{"title":"Wideband Air-Filled Coaxial Filter Line","authors":"Jori M. Platt,&nbsp;Ljubodrag B. Boskovic,&nbsp;Dejan S. Filipovic","doi":"10.1002/mop.70030","DOIUrl":"https://doi.org/10.1002/mop.70030","url":null,"abstract":"<div>\u0000 \u0000 <p>A design for manufacturing (DFM) of a well-performing wideband coaxial filter line using direct metal laser sintering (DMLS) additive manufacturing is proposed. The demonstrated transmission line is an air-filled coaxial line chosen for low loss and consistent group delay over the bandwidth. Transmission line theory is used first to account for the impact of the shorted stub needed to support the central conductor. Deviations due to parasitics are described to transition the design from an ideal model to a physical prototype. The constraints inherent in DMLS are discussed and accounted for throughout the DFM. This process is demonstrated with a prototype having return and insertion losses of greater than 10 dB and less than 1.64 dB, respectively, over a 5.3:1 bandwidth from 6.4 to 33.9 GHz with a flat group delay of 129 ps ± 7%.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664913","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 self-packaged multilayer all-metal integrated suspended slotline dual-band filter","authors":"Yi Wu,&nbsp;Kaixue Ma,&nbsp;Ming Yin","doi":"10.1002/mop.70001","DOIUrl":"https://doi.org/10.1002/mop.70001","url":null,"abstract":"<p>This paper introduces a novel implementation technology for realizing dual-band bandpass filtering responses using high-<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>Q</mi>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $Q$</annotation>\u0000 </semantics></math> slotline resonators with self-packaged multilayer configuration. The concept of a 3D slotline is introduced, which utilizes the innovative metal-integrated suspended line (MISL) technology. This technology utilizes an all-metal structure, effectively eliminating dielectric loss. Furthermore, the implementation of an encapsulated structure significantly reduces radiation loss in the slotlines. Thus, the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>Q</mi>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $Q$</annotation>\u0000 </semantics></math> factors are greatly improved. Based on MISL, a dual-band bandpass filter with wideband responses and multiple transmission zeros was designed, fabricated, and tested based on 3D cascaded-mode half-wavelength resonators. The test results demonstrated a high level of consistency with the simulation results, confirming the high-<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>Q</mi>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $Q$</annotation>\u0000 </semantics></math> characteristics of the proposed 3D slotlines.</p>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664911","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":"Adaptive Weighted Bregman Huber Total Variation Method for Terahertz Computed Tomography","authors":"Xingzeng Cha,&nbsp;En Li,&nbsp;Dakun Lai","doi":"10.1002/mop.70023","DOIUrl":"https://doi.org/10.1002/mop.70023","url":null,"abstract":"<div>\u0000 \u0000 <p>To improve the image quality of terahertz (THz) continuous wave (CW) computed tomography (CT) under sparse-view projections, a sparse-view adaptive-weighted Bregman Huber total variation (AW-BHTV) method is proposed and experimentally evaluated at 0.11 THz. The Huber function is served as the fidelity term and TV function is worked for the regularization term, optimized by the adaptive weights, incorporating with iterative algorithms containing the modified simultaneous algebraic reconstruction technique (MSART) and the iterative filtered back-projection (FBP). Sparse-view reconstruction experiments are carefully implemented via polystyrene (PS) foam samples: Sample 1 and Sample 2, respectively. Under 20 projection angles by MSART based AW-BHTV, the values of rooted mean-square-error (RMSE), peak signal-to-noise ratio (PSNR), structure similarity (SSIM) and feature similarity (FSIM) are 0.0061, 22.1427, 0.8738 and 0.9902 for Sample 1 together with 0.0051, 22.9101, 0.8376 and 0.9885 for Sample 2 separately. All of the results above suggest that the proposed AW-BHTV method can effectively protect image details and strengthen image quality in sparse-view THz CW CT.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664912","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 Dual-Polarized Wide-Angle Scanning Linear Phased Array Antenna With Simple Decoupling Structure","authors":"Qi-Qiang Li,&nbsp;Yao Yang,&nbsp;Jian-Ying Li,&nbsp;Shi-Gang Zhou","doi":"10.1002/mop.70026","DOIUrl":"https://doi.org/10.1002/mop.70026","url":null,"abstract":"<div>\u0000 \u0000 <p>A dual-polarization linear phased array with a simple decoupling structure is designed for wide scanning in this letter. The suggested antenna is made up of two printed dipole antennas that are orthogonally arranged and have a high cross-polarized isolation. Metal sheets cladding on antenna substrates serve as a decoupling structure, with an array element spacing of 0.48 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mi>λ</mi>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${rm{lambda }}$</annotation>\u0000 </semantics></math>. A linear phased array of seven elements is fabricated and measured to ensure that the planned array is feasible. The simulated and measured results demonstrate that the phased array can scan its main beam up to ±75° in dual-polarized excitations at 5.6–6.4 GHz. The co-polarized mutual coupling is below −28 dB, and the active reflection coefficient of the element is less than −15 dB.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664562","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":"Compact Wide-Stopband QMSIW-Based BPF for X-Band Applications","authors":"Amrita Medda,&nbsp;Amit R. Azad,&nbsp;Gunjan Srivastava,&nbsp;Akhilesh Mohan,&nbsp;Manoranjan Sinha","doi":"10.1002/mop.70018","DOIUrl":"https://doi.org/10.1002/mop.70018","url":null,"abstract":"<div>\u0000 \u0000 <p>A novel and compact two-pole quarter mode substrate integrated waveguide (QMSIW) based bandpass filter with ultra-wide stopband characteristics (rejection level &gt; 20 dB, up to 4.05<i>f</i>₀, where <i>f</i>₀ is the center frequency of the bandpass filter) is designed and developed in this paper. The designed second-order filter comprises of two circular QMSIW cavity resonators. The filter is designed using the dominant TM₀₁₀ mode of the circular SIW cavity. The TM₀₁₀ modes of cavities are coupled through the arc-shaped slot etched in the middle layer. To verify the present design methodology, a second-order bandpass filter is fabricated and its characteristics are measured. The designed bandpass filter shows outstanding performance in terms of good fractional bandwidth of 14.45%, lower insertion loss of 2 dB and wider stopband behavior (rejection better than 20 dB up to 4.05<i>f</i>₀) in a given footprint. The experimental results of the filter matches well the EM-simulated ones.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664635","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":"Flexible Impedance Matching in a Self-Diplexing Patch Antenna","authors":"Ashish Chandelkar,&nbsp;Arvind Kumar","doi":"10.1002/mop.70024","DOIUrl":"https://doi.org/10.1002/mop.70024","url":null,"abstract":"<div>\u0000 \u0000 <p>This study introduces a new approach to achieve flexible impedance matching in a self-diplexing conventional patch antenna by using paired vias for impedance bandwidth tunability. The antenna design incorporates a rectangular radiating patch, an orthogonal arrangement of a couple of paired vias, and a bottom ground plane. The patch is excited with the help of two orthogonal microstrip feeds aligned along the centerline of the broadside and narrow sides of the patch. The orthogonal vias set enables dynamic impedance matching in two frequency bands, lower and upper ranging from 2 to 3 GHz. Optimized via placement achieves high decoupling between input ports, facilitating the self-diplexing phenomenon. To validate the proposed concept, a prototype with patch dimensions of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mn>49</mn>\u0000 \u0000 <mo>×</mo>\u0000 \u0000 <mn>40</mn>\u0000 \u0000 <mo>×</mo>\u0000 \u0000 <mn>1.57</mn>\u0000 <mspace></mspace>\u0000 \u0000 <msup>\u0000 <mtext>mm</mtext>\u0000 \u0000 <mn>3</mn>\u0000 </msup>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $49times 40times 1.57,{text{mm}}^{3}$</annotation>\u0000 </semantics></math> has been analyzed, fabricated, and subjected to comprehensive experimental study. The experimental results demonstrate the successful realization of two distinct operating frequency bands, centered around 2.47 and 2.66 GHz, each exhibiting peak gain values of 5.75 and 6.31 dBi, respectively. The input port isolation values are noteworthy, measuring at −34B and −29.5 dB for lower and upper operating frequency bands, respectively. The design offers a low-profile, minimally coupled structure with independent band control and the unique ability to simultaneously transmit and receive signals.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596414","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":"Highly Sensitive Fiber Optic Current Sensors with Integrated λ/4 Retarder","authors":"Shuo Chen,&nbsp;Zhanyuan Liu,&nbsp;Xiaochen Niu,&nbsp;Jie Huang,&nbsp;Lei Zhao,&nbsp;Yuan Ke,&nbsp;Li Xia","doi":"10.1002/mop.70025","DOIUrl":"https://doi.org/10.1002/mop.70025","url":null,"abstract":"<div>\u0000 \u0000 <p>Fiber optic current sensors have made unprecedented contributions to the safety and security of power grids. The λ/4 retarder, as a key component for generating circular polarization, can significantly enhance the performance of fiber optic current sensors (FOCS) due to its superior characteristics. However, traditional methods of fabricating homemade λ/4 retarders have inherent flaws. This study replaced the traditional λ/4 retarder in the all-fiber current sensor with an integrated λ/4 retarder, which is proposed to convert linearly polarized light into circularly polarized light by controlling different spin rates of the spun fiber. The current sensitivity was increased from 0.235 to 0.404 mV/mA, and the noise was suppressed.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596415","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 rapid evaluation method for pumpkin sensory quality based on near-infrared spectroscopy","authors":"Zhuopin Xu,&nbsp;Xiaohong Li,&nbsp;Guangxia Zhao,&nbsp;Liwen Tang,&nbsp;Zuyun Dai,&nbsp;Wei Dai,&nbsp;Chaowu Chen,&nbsp;Yuejin Wu,&nbsp;Pengfei Zhang,&nbsp;Qi Wang","doi":"10.1002/mop.70016","DOIUrl":"https://doi.org/10.1002/mop.70016","url":null,"abstract":"<p>The sensory quality (SQ) of pumpkin fruit is one of the most important quality indexes for consumers. In this study, a rapid pumpkin SQ evaluation method based on near-infrared spectroscopy (NIRS) was introduced. The starch and moisture contents of pumpkins were first determined by NIRS, and then the SQ of pumpkin could be estimated indirectly by these components. Test was carried out on 97 samples of 34 pumpkin fruits. The pumpkin starch and water NIRS models based on variable dimension particle swarm optimization combined moving window (VDPSO-CMW) and standard normal variate transformation (SNV) showed the best predictive performances, whose predictive determination coefficients (<i>R</i>²_p) were 0.775 and 0.932, respectively. A multiple linear regression model (correlation coefficient = 0.788) was established based on the prediction results of the two models and the SQ values obtained from cooking experiments. The proposed method has the potential to provide effective support for pumpkin breeding and production.</p>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574016","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":"Asymmetric Coplanar Strip Loaded With Meander Lines for Multiband Operations Using ANN Optimization","authors":"S. Janu Priya,&nbsp;R. Samson Daniel","doi":"10.1002/mop.70019","DOIUrl":"https://doi.org/10.1002/mop.70019","url":null,"abstract":"<div>\u0000 \u0000 <p>A miniaturized asymmetric coplanar strip fed with meander lines is developed for hexaband wireless applications. Multiband with compact size of the antenna is developed by using meander lines. The designed antenna is enhanced by an increased number of meander lines. The invented antenna is composed of three meander lines, it yields the antenna to excite 1.13, 2.35, 2.91, 3.46, 3.96, and 4.5 GHz, respectively. The prototype antenna is fed by ACS, which is printed on a 14 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mo>×</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $times $</annotation>\u0000 </semantics></math> 24 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <mo>×</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $times $</annotation>\u0000 </semantics></math> 1.6 mm³ FR-4 substrate and dielectric constant of <i>Ɛ</i>_r = 4.4. MATLAB tool is utilized in the ANN computation to amend the physical values of the antenna. The calibrated and simulated radiation attributes are identical with each other. The designed antenna provides distinguishing characteristics such as good reflection coefficient, impedance matching, and size miniaturization. It imparts empirical peak gains of 0.028 dBi at 1.14 GHz, 1.305 dBi at 2.35 GHz, 1.54 dBi at 2.86 GHz, 1.79 dBi at 3.43 GHz, 2.43 dBi at 3.96 GHz, and 2.58 dBi at 4.5 GHz, which is suitable for GSM/WLAN/WiMAX and C-band wireless applications.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142563015","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":"Investigations of all optical 2×4 decoder based on PhC structure and nonlinear ring resonators","authors":"Asghar Askarian,&nbsp;Fariborz Parandin","doi":"10.1002/mop.70004","DOIUrl":"https://doi.org/10.1002/mop.70004","url":null,"abstract":"<p>In this paper, all optical 2 × 4 decoder (AODEC) is provided using threshold switching method in 2D photonic crystal (PC) structures which has low optical loss and most widely used in photonic integrated circuits (PICs). The proposed optical decoder is designed using silicon pillars with a refractive index of 3.46 perforated in the air background in a cubic lattice with a lattice constant of 585 nm. The proposed structure is composed of seven optical waveguides and three nonlinear ring resonators. Plane wave expansion (PWE) and finite difference time domain (FDTD) methods have been used to obtain and analyze the photonic band gap (PBG) range and performance of the designed AODEC, respectively. The proposed optical device achieves a contrast ratio (CR) of 8.98 dB, time delay of 2 ps and switching speed of 500 GHz at the optical wavelengths of 1550 nm. According to results, high data bit rate and contrast ratio, compactness, low power consumption and ultra-fast operation are the main advantages of designed 2 × 4 AODEC compared with the previous structures.</p>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"66 11","pages":""},"PeriodicalIF":1.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142563013","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}