Radio Science最新文献_第8页

Front matters 前面问题

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-04-02 DOI: 10.1029/rds.70039

引用次数: 0

A low-cost via-less air-filled waveguide in multilayer PCB for high-frequency circuits based on artificial magnetic conductors 基于人工磁性导体的多层PCB高频电路的低成本无过孔充气波导

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-06-03 DOI: 10.1029/2026RS008720

S. Panigrahi;H. T. Chou;S. Kawdungta;D. Torrungrueng

{"title":"A low-cost via-less air-filled waveguide in multilayer PCB for high-frequency circuits based on artificial magnetic conductors","authors":"S. Panigrahi;H. T. Chou;S. Kawdungta;D. Torrungrueng","doi":"10.1029/2026RS008720","DOIUrl":"https://doi.org/10.1029/2026RS008720","url":null,"abstract":"This paper proposes a novel, low-cost, AMC-based via-less approach to implementing air-filled waveguides (AFWs) embedded within multilayer printed circuit board structures to achieve low propagation loss. Three layers of low-cost FR4 substrates are sandwiched together using prepreg to form the basic AFW structure. To overcome the technical impossibility of seamless vertical metalization in multilayer LCP or FR4 processes, an electroplating technology combined with planar artificial magnetic conductor (AMC) surfaces is employed to construct the waveguide sidewalls. The AMC structures effectively create a virtual magnetic wall that suppresses electromagnetic (EM) leakage through the unplated prepreg layers. To further enhance field confinement and reduce junction leakage, a modified AMC structure incorporating longitudinal metal strips is introduced. Numerical simulations at 77 GHz demonstrate that the proposed AFW achieves a remarkably low theoretical propagation loss of 0.08 dB/cm. A prototype was fabricated and measured to validate the design. While transition-region fabrication sensitivities affected the absolute insertion loss, the intrinsic propagation loss of the waveguide core was extracted using a multi-length transmission line method, yielding an experimental result of 0.16 dB/cm. The proposed architecture provides a highly integrable, cost-effective, and high-performance solution for millimeter-wave (mmWave) and sub-terahertz applications, such as automotive radar and 5G/6G communications, where traditional substrate-integrated waveguides (SIW) suffer from high dielectric losses.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 5","pages":"1-12"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148146801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Millimeter-wave antennas: A comprehensive state-of-the-art review of design approaches, operating bands, challenges, and applications in body-centric and emerging systems 毫米波天线：对以身体为中心和新兴系统的设计方法、工作频带、挑战和应用的综合评述

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-03-01 Epub Date: 2026-06-03 DOI: 10.1029/2026RS008662

Sarra Khacha;Chemseddine Zebiri;Mohammad Alibakhshikenari;Djamel Sayad;Issa Elfergani;Muhammad Akmal Chaudhary;Nisar Ahmad Abbasi;Arpan Desai;Jonathan Rodriguez;Takfarinas Saber;Ernesto Limiti

{"title":"Millimeter-wave antennas: A comprehensive state-of-the-art review of design approaches, operating bands, challenges, and applications in body-centric and emerging systems","authors":"Sarra Khacha;Chemseddine Zebiri;Mohammad Alibakhshikenari;Djamel Sayad;Issa Elfergani;Muhammad Akmal Chaudhary;Nisar Ahmad Abbasi;Arpan Desai;Jonathan Rodriguez;Takfarinas Saber;Ernesto Limiti","doi":"10.1029/2026RS008662","DOIUrl":"https://doi.org/10.1029/2026RS008662","url":null,"abstract":"This paper reviews and classifies more than 120 recent contributions on millimeter-wave (mm-wave) antennas, with emphasis on their operating bands, design methods, and application domains. It surveys the main mm-wave frequency ranges and their use in 5G/6G communications, radar and sensing, biomedical and body-centric systems, imaging, and radio-frequency energy harvesting and wireless power transfer. The review compares different antenna design approaches, including array and MIMO architectures, metasurface- and metamaterial-based structures, and integration-oriented solutions such as wearable platforms, outlining their typical trade-offs, implementation challenges, and limitations in terms of bandwidth, efficiency, miniaturization, and robustness. Particular attention is given to antennas operating in proximity to the human body, where performance is strongly influenced by tissue electromagnetic properties and safety constraints. In this context, the paper discusses design criteria based on Specific Absorption Rate (SAR) and Power Density (PD), as well as the role of physical, numerical, and voxel phantoms for accurate performance assessment and regulatory compliance. The review highlights practical use cases across these application areas and identifies open challenges and future research directions, including the exploitation of metasurfaces and Radio over fiber, to enable safe, efficient, and adaptive mm-wave antennas for emerging systems.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 5","pages":"1-20"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148146842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Environmental boundary estimation of urban areas using FMCW radar with data clustering for UAV detection 基于数据聚类的FMCW雷达城市环境边界估计

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-02-01 DOI: 10.1029/2025RS008392

Seksan Eiadkaew;Akkarat Boonpoonga;Lakkhana Bannawat;Krit Athikulwongse;Danai Torrungrueng

{"title":"Environmental boundary estimation of urban areas using FMCW radar with data clustering for UAV detection","authors":"Seksan Eiadkaew;Akkarat Boonpoonga;Lakkhana Bannawat;Krit Athikulwongse;Danai Torrungrueng","doi":"10.1029/2025RS008392","DOIUrl":"https://doi.org/10.1029/2025RS008392","url":null,"abstract":"The increasing presence of unmanned aerial vehicles (UAVs) in urban environments presents challenges for reliable detection due to clutter caused by buildings, infrastructure, and other static structures. Conventional Doppler-based radar methods often struggle in such conditions, particularly when UAVs exhibit low radial velocities. This paper presents a non-Doppler scattering-point framework for UAV detection, based on a frequency-modulated continuous wave (FMCW) radar system operating in the X-band (9.950–10.026 GHz). The system utilizes a rotating platform for azimuth scanning and applies azimuth-range mapping combined with adaptive DBSCAN clustering and β-expanded convex hull boundary estimation to reduce false detections from static clutter. Experimental validation was conducted in a controlled urban setting with multiple buildings and varied UAV trajectories. The method was evaluated across several elevation angles, demonstrating consistent detection performance and improved distinction between UAV detections and points caused by environmental clutter. These results support the use of FMCW radar and spatial clustering techniques as an effective alternative to Doppler-independent methods for UAV monitoring in complex environments.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 2","pages":"1-19"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147362530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Six-component electromagnetic wave measurements of sprite-associated lightning 精灵闪电的六分量电磁波测量

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-02-01 DOI: 10.1029/2025RS008543

Martin Füllekrug;Michael Kosch;Gavin Dingley;Xue Bai;Liliana Macotela

{"title":"Six-component electromagnetic wave measurements of sprite-associated lightning","authors":"Martin Füllekrug;Michael Kosch;Gavin Dingley;Xue Bai;Liliana Macotela","doi":"10.1029/2025RS008543","DOIUrl":"https://doi.org/10.1029/2025RS008543","url":null,"abstract":"Low frequency electromagnetic waves emitted by sprite-producing lightning are normally measured using vertical electric fields or horizontal magnetic fields. Here we report for the first time the simultaneous measurement of electromagnetic waves from sprite-producing lightning in all six electromagnetic field components E<inf>x</inf>, E<inf>y</inf>, E<inf>z</inf>, H<inf>x</inf>, H<inf>y</inf>, and H<inf>z</inf>. A rigorous assessment of the horizontal electric field measurements with dipole antennas in two independent calibration experiments shows that a timing uncertainty of ∼ 1–2 ns can be achieved, well above the current fundamental limit of the timing accuracy ∼1–5 ps. The coupling between the electric and magnetic fields is quantified using a transfer matrix, allowing the magnetic field to be reconstructed accurately from electric field measurements. The cross product of electric and magnetic fields is used to calculate peak energy fluxes and arrival azimuths from sprite-producing lightning. It is found that peak energy fluxes vary between ∼ 10—1,000 μW/m<sup>2</sup> and that the differences between the measured and expected arrival azimuths are practically normally distributed with a mean and standard deviation of −8.0° ± 2.2°. It is concluded that horizontal electric field measurements are well suited to characterize electromagnetic waves with added benefits, including the ease of deployment in harsh environments, cost-effectiveness and scalability, for example for polarisation measurements in large low frequency arrays. The significance of this study is that it can be used as a pathfinder mission to identify critical technical requirements for the array deployment during the Africa2Moon lander mission.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 2","pages":"1-13"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147362528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Behavior of evaporation ducts in stable and unstable surface layers 稳定和不稳定表层中蒸发管道的行为

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-02-01 DOI: 10.1029/2025RS008402

Katherine Mulreany;Qing Wang

{"title":"Behavior of evaporation ducts in stable and unstable surface layers","authors":"Katherine Mulreany;Qing Wang","doi":"10.1029/2025RS008402","DOIUrl":"https://doi.org/10.1029/2025RS008402","url":null,"abstract":"The atmospheric surface layer over the ocean has a strong impact on electromagnetic (EM) wave propagation in the lowest 100 m of the atmosphere. Due to surface evaporation, a strong vertical gradient in water vapor forms in this layer, resulting in an evaporation duct which may greatly increase detection ranges for sensors and targets within the duct. When a warm air mass moves over cooler water, the surface layer forms a stable thermal stratification whose ducting characteristics are much less understood compared to its counterpart, the unstable surface layer. In this study, we perform a sensitivity study to examine the characteristics of the stable surface layer profiles and how their impacts on EM propagation differ from those in the unstable cases. Using buoy-based measurements from both coasts of the United States as input to a surface layer model, refractivity profiles were generated as input to a propagation model to characterize path loss. The results suggest that the stable surface layers present more complex propagation scenarios with a broad range of propagation loss including the maximum propagation loss in the subrefractive conditions and maximum trapping in cases of deep evaporation duct heights. The results also suggest strong dependance of propagation loss on evaporation duct height when the transmitter height is above the duct. In contrast, propagation loss is no longer sensitive to evaporation duct height once the transmitter is within the duct. This research also reveals the role of 2-m curvature of the M-profile in defining the propagation regimes.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 2","pages":"1-14"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147362529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Real heights of SuperDARN F region echoes inferred from electron density measurements by the Rankin Inlet and RISR-C radars 由Rankin Inlet和RISR-C雷达的电子密度测量推断出superdamyf区回波的真实高度

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-02-01 DOI: 10.1029/2025RS008436

Alexander V. Koustov;Mehdi Ghalamkarian Nejad;Hayden Fast;Pavlo V. Ponomarenko

引用次数: 0

Temporal dependencies between total lightning and rainfall in multicellular systems: A predictive approach for torrential rain during summer thunderstorms in Japan 多蜂窝系统中总闪电和降雨之间的时间相关性：日本夏季雷暴期间暴雨的预测方法

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-02-01 DOI: 10.1029/2025RS008380

D. Mondal;Y. Hobara;H. Kikuchi;J. Lapierre;P. Le Floch;O. Kameya;N. Kawaguchi;K. Motojima;K. Shiokawa;T. Eguchi;D. Okano;T. Nakamura

{"title":"Temporal dependencies between total lightning and rainfall in multicellular systems: A predictive approach for torrential rain during summer thunderstorms in Japan","authors":"D. Mondal;Y. Hobara;H. Kikuchi;J. Lapierre;P. Le Floch;O. Kameya;N. Kawaguchi;K. Motojima;K. Shiokawa;T. Eguchi;D. Okano;T. Nakamura","doi":"10.1029/2025RS008380","DOIUrl":"https://doi.org/10.1029/2025RS008380","url":null,"abstract":"Recently, detailed spatio-temporal analysis utilizing X-band multi-parameter radar-derived 3D volume scan and total lightning data in Japan, have revealed the peak in-cloud (IC) lightning occurs 5–10 min prior to maximum ground rainfall in individual thunderstorm cells during heavy rainfall events. This temporal relation holds the potential for improving real-time monitoring and nowcasting of torrential rain causing natural disaster such as flash floods. However, cell interactions such as merging and splitting of the cells are often observed in multicellular thunderstorms, which cause abrupt fluctuation in the total lightning rate and make it difficult to track the storm evolution. To address this, we propose an area-correction method based on the lightning activity (in terms of cell area ratio before and after merging/splitting) of individual cell. Preliminary observation results of two multicellular thunderstorm events with heavy rainfall (∼100 mm/hr) that exhibited cell merging and splitting during their life cycle are demonstrated. The area-correction resulted in a reasonable and corresponding trend in the temporal behavior of IC lightning rate and ground precipitation volume, with the peak IC rate preceding the peak ground PV by 5–10 min. We also demonstrate a promising approach for short-term prediction of ground rainfall with high accuracy (correlation coefficient between observed and predicted PV was 0.84–0.94), by means of a moving linear regression model, using recent IC observations. These results highlight the potential of total lightning for short-term rainfall prediction in both isolated and multicellular thunderstorms.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 2","pages":"1-20"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147362527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ionospheric variability across solar cycles 23 and 24 in the Indian longitude sector: GPS observations and IRI model validation 印度经度扇区太阳周期23和24的电离层变率：GPS观测和IRI模式验证

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-02-01 DOI: 10.1029/2025RS008458

Mini Rajput;P R Shreedevi;Sanjay Kumar;Abhay Kumar Singh

{"title":"Ionospheric variability across solar cycles 23 and 24 in the Indian longitude sector: GPS observations and IRI model validation","authors":"Mini Rajput;P R Shreedevi;Sanjay Kumar;Abhay Kumar Singh","doi":"10.1029/2025RS008458","DOIUrl":"https://doi.org/10.1029/2025RS008458","url":null,"abstract":"This study investigates Total Electron Content (TEC) variations across the Indian longitude sector (75°–85°E) from 2004 to 2014, spanning descending phase solar cycle 23 and ascending/peak phases of solar cycle 24, using GPS data from four stations: Bangalore (IISC), Varanasi (BHUP), Bishkek (POL), and Novosibirsk (NOVM). We analyze latitudinal, seasonal, and solar activity-driven TEC variability and evaluate IRI-2016 and IRI-2020 model performance. Low-latitude stations (IISC, BHUP) exhibit strong equinoctial peaks (∼40–70 TECU), semi-annual anomalies, noontime bite-outs driven by the equatorial ionization anomaly and E × B drifts, and nighttime enhancements during high solar activity. Mid-latitude stations (POL, NOVM) show lower TEC (∼20–35 TECU) with seasonal variations influenced by thermospheric winds. Equinoctial asymmetry is evident, with October TEC surpassing March-April in 2011–2013 due to rising solar EUV flux. TEC strongly correlates with F10.7/SSN (R<sup>2</sup> ∼0.65–0.78, higher at low latitudes), reflecting strong solar control at low-latitudes. At low latitudes, IRI-2020 outperforms IRI-2016 with lower RMSE, while at mid-latitudes IRI-2016 shows slightly better performance. Differential TEC (DTEC) reveals larger deviations at low latitudes ranging from — 26.8 to +30.81 TECU, compared to smaller deviations at mid-latitudes ranging from — 8.71 to + 18.50 TECU. Both models capture equinoctial enhancements but overestimate winter anomaly occurrence and show large errors during equinoxes, particularly at low latitudes. Unlike prior studies, this work examines TEC across an entire solar cycle, revealing regional model limitations. These findings enhance ionospheric model validation, critical for improving satellite navigation and space weather forecasting in the Indian sector.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"61 2","pages":"1-20"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147362517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A fast and accurate full-wave propagator for modeling the electromagnetic propagation in a radio occultation configuration 一种快速准确的全波传播器，用于模拟无线电掩星结构中的电磁传播

IF 1.5 4区地球科学

Radio Science Pub Date : 2026-02-01 DOI: 10.1029/2025RS008247

Clémence Allietta;Rémi Douvenot;Sonia Cafieri

引用次数: 0