Radio Science最新文献_第8页

Compact and wideband cavity-backed antenna with elliptical coupling slot and elliptical aperture for satellite communications transceiver applications 具有椭圆耦合槽和椭圆孔径的小型宽带空腔背天线，用于卫星通信收发器

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-02-01 DOI: 10.1029/2024RS008120

Y. Asci;C. Turkmen;M. Secmen

{"title":"Compact and wideband cavity-backed antenna with elliptical coupling slot and elliptical aperture for satellite communications transceiver applications","authors":"Y. Asci;C. Turkmen;M. Secmen","doi":"10.1029/2024RS008120","DOIUrl":"https://doi.org/10.1029/2024RS008120","url":null,"abstract":"A wideband full-metal cavity-backed antenna with elliptical coupling slot and elliptical aperture is proposed. The antenna consists of two elliptical structures, a coupling slot and a radiating aperture, which are placed on the feed waveguide side and the load side of a rectangular metal cavity resonator, respectively. By using an elliptical slot/aperture, the impedance bandwidth and gain of the antenna are found to be considerably improved in the same footprint and without increasing complexity compared to rectangular slot/aperture and also circular aperture. A prototype of the proposed wideband antenna is fabricated by using the additive manufacturing techniques of 3D printing with polylactic acid (PLA) material, which is covered with aluminum tape to validate the design at Ku-band for satellite communication (SatCom). The measured results show that the antenna has an impedance bandwidth of 4 GHz (10.86–14.86 GHz for |S<inf>11</inf>| < —15 dB), which gives a fractional bandwidth (FBW) of 31.1%. With low cross-polarization being less than — 25 dB at broadside, the antenna has a peak gain of 9 dBi. The proposed antenna is also compact, with a total volume of about 1.1λ<inf>0</inf><sup>3</sup> at the center frequency.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 2","pages":"1-13"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535440","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

Design and optimization of a low-cost 5-m radio telescope at princess Nourah university (PNU), Saudi Arabia 沙特阿拉伯诺拉公主大学（PNU）低成本5米射电望远镜的设计与优化

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-02-01 DOI: 10.1029/2024RS008170

Yazan M. Allawi;Eman M. Moneer;Modar Shbat;Walid M. Dyab;Mosab J. Banisalman;Norah M. Alwadai

{"title":"Design and optimization of a low-cost 5-m radio telescope at princess Nourah university (PNU), Saudi Arabia","authors":"Yazan M. Allawi;Eman M. Moneer;Modar Shbat;Walid M. Dyab;Mosab J. Banisalman;Norah M. Alwadai","doi":"10.1029/2024RS008170","DOIUrl":"https://doi.org/10.1029/2024RS008170","url":null,"abstract":"This paper presents the design and optimization of a low-cost, 5-m radio telescope developed at Princess Nourah University (PNU), focusing on the 1,420 MHz spectral line of neutral hydrogen (HI) for studying the structure and dynamics of the Milky Way galaxy. The design process integrates key principles of radio telescope engineering, including the optimization of the parabolic dish's geometry, reflectivity, and feed horn design and positioning. Key design outcomes include achieving a sensitivity of 19.63 m<sup>2</sup> and an angular resolution of 2.94° providing our telescope with the ability to detect faint cosmic signals. Additionally, the focal length was optimized at 1.75 m with conical feed horn of circular aperture radius of 81.7 mm providing a directivity of 6.47 dB and an aperture efficiency of 51% achieving semi-optimal illumination for the designed reflector to minimize the signal loss. The resulting telescope gain of approximately 35 dB supports clear signal capture within the required frequency range. These performance metrics were verified through both simulations and experimental observations, confirming the high performance of our proposed radio telescope design. The advantages of this design include its affordability, replicability, and suitability for educational and research purposes, making it an accessible tool for radio astronomy studies in developing regions. The proposed radio telescope offers a cost-effective solution for institutions seeking to engage in astronomical research and develop hands-on learning experiences in antenna design and signal processing.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 2","pages":"1-17"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535509","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

Comparative analysis of performance for optimization-based transionospheric SAR autofocus 基于优化的过渡层SAR自动对焦性能比较分析

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-02-01 DOI: 10.1029/2024RS008168

Mikhail Gilman;Semyon Tsynkov

引用次数: 0

Characterization of the effective conductivity in radio frequency of additive manufacturing materials 增材制造材料射频有效导电性的表征

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-02-01 DOI: 10.1029/2024RS008149

Carmen Bachiller;Alvaro Ferrer;Aleksandr Voronov;Murta Capella;Francisco Boscá;M. Luisa Marin;Lluc Sempere;Mirko Kunowsky;Asunción Martínez-García

引用次数: 0

Retraction: A survey of five generations of MIMO multiband base station antennas 摘要：五代MIMO多波段基站天线的研究

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-02-01 DOI: 10.1029/rds.21394

引用次数: 0

Application of SuperDARN interferometry for improved estimates of Doppler velocity and echo geolocation superdam干涉测量在改进多普勒速度估计和回波定位中的应用

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-01-01 DOI: 10.1029/2024RS008084

P. Ponomarenko;M. Ghalamkarian Nejad;A. V. Koustov

{"title":"Application of SuperDARN interferometry for improved estimates of Doppler velocity and echo geolocation","authors":"P. Ponomarenko;M. Ghalamkarian Nejad;A. V. Koustov","doi":"10.1029/2024RS008084","DOIUrl":"https://doi.org/10.1029/2024RS008084","url":null,"abstract":"It has been previously established that the Doppler velocities of F-region ionospheric echoes observed by the Super Dual Auroral Radar Network (SuperDARN) at high frequencies (HF, 8–20 MHz) are persistently lower than those measured by other instruments at the same locations. This was attributed to the ionospheric refractive index for HF radio waves being noticeably smaller than one. The refractive index values can be obtained in two ways: based on electron density estimates from a co-located instrument or a model, or by deriving them from SuperDARN elevation angle data. To compare these methods, we considered line-of-sight Doppler velocity observations by the Rankin Inlet (RKN) SuperDARN radar and the Resolute Bay Incoherent Scatter Radars (RISR). The velocity data were supplemented by electron density measurements from RISR. The elevation angle data were also used for accurate determination of SuperDARN echo geolocation because the actual ground range to the echo location may significantly differ from that obtained with the conventional SuperDARN models. The RISR Doppler velocity values were used as a reference to the RKN observations via 0.5-hop and 1.5-hop propagation paths. Correction by the index of refraction based on both maximum electron density from the RISR and elevation angle data from RKN brought 0.5-hop data close to the RISR velocity values, with the latter representing a self-contained approach. However, for 1.5-hop echoes from the polar cap, the uncorrected SuperDARN velocities exceeded those from RISR. We discuss potential causes of this apparent anomaly.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 1","pages":"1-15"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106325","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

Front matters 前面问题

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-01-01 DOI: 10.1002/rds.21325

引用次数: 0

Examining the power law relationship between absorption and frequency using spectral riometer data 利用光谱里程计的数据检验吸收和频率之间的幂律关系

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-01-01 DOI: 10.1029/2024RS007951

R. A. D. Fiori;A. Kero;R. Gillies;T. G. Cameron;C. Cully;R. Ghaffari

{"title":"Examining the power law relationship between absorption and frequency using spectral riometer data","authors":"R. A. D. Fiori;A. Kero;R. Gillies;T. G. Cameron;C. Cully;R. Ghaffari","doi":"10.1029/2024RS007951","DOIUrl":"https://doi.org/10.1029/2024RS007951","url":null,"abstract":"High frequency radio wave propagation is sensitive to absorption in the D and lower E-region ionosphere. Absorption models typically characterize attenuation expected at 30 MHz, meaning scaling relationships are required to map to absorption expected at other frequencies. This is important when evaluating absorption at <20 MHz, as these frequencies are typically used for communication, and are highly sensitive to ionospheric disturbances. Typically, a power law relationship between absorption and frequency with a coefficient of n = − 2 is used. This relationship can be demonstrated through consideration of the Appleton-Hartree equation. This paper examines the performance of this relationship using data from the Kilpisjärvi Atmospheric Imaging Receiver Array for 13–14 November 2012. Using absorption measured at 30 MHz as a baseline, the power law relationship was used to calculated absorption at frequencies of 10–80 MHz. For this event, the power law relationship performed well when the measured absorption at 30 MHz was <1–2 dB, but strongly overestimated measurements as absorption increased. Performance improved when n was allowed to vary as a function of the overall level of absorption at 30 MHz. This accounts for local ionospheric changes associated with absorption events that change the balance of parameters in the Appleton-Hartree equation causing deviation from n = − 2. To further accommodate deviations associated with both local ionospheric disturbances and ambient electromagnetic noise contributions, an empirical relationship relating the logarithm of absorption to frequency was evaluated as a function of overall absorption. Compared to the simplified n = − 2 power law relationship between absorption and frequency, the new relationship better represents measured absorption for the event studied.","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 1","pages":"1-14"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106330","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

Angle and polarization insensitive RCS reduction metasurface based on hybrid mechanism of polarization conversion and absorption 基于偏振转换和吸收混合机制的角度和偏振不敏感RCS还原超表面

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-01-01 DOI: 10.1029/2024RS008052

H. J. Zhao;X. Y. Dai;H. Chu;X. H. Zhu;Y. X. Guo

{"title":"Angle and polarization insensitive RCS reduction metasurface based on hybrid mechanism of polarization conversion and absorption","authors":"H. J. Zhao;X. Y. Dai;H. Chu;X. H. Zhu;Y. X. Guo","doi":"10.1029/2024RS008052","DOIUrl":"https://doi.org/10.1029/2024RS008052","url":null,"abstract":"This article introduces the concept, theory, and design of an angle and polarization insensitive radar cross section (RCS) reduction metasurface, using a hybrid mechanism of polarization conversion and absorption. By introducing ladder- and rectangle-shaped metallic patches in the vertical dimension of a 3-D structure, polarization conversion rate (PCR) deterioration, brought by the increase of equivalent substrate thickness at oblique incidences, can be suppressed. Furthermore, lumped resistors are loaded at proper places in each polarization conversion cell, to achieve the power absorption while maintain the angular insensitivity of the PCR. With the above hybrid mechanism, a stable 10-dB RCS reduction can be achieved regardless of the angle of incidence in a wide range and polarization directions. An equivalent circuit model is established for explaining the physical mechanism of the proposed metasurface. For validation, a prototype is fabricated and tested. Measurement results indicate that, for both monostatic RCS at the normal incidence and specular RCS of off-normal incidences from 0° to 45°, a 10-dB TE- and TM-mode RCS reduction can be achieved in the entire X-band (8–12 GHz) and Ku-band (12–18 GHz).","PeriodicalId":49638,"journal":{"name":"Radio Science","volume":"60 1","pages":"1-11"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106324","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 novel flexible ultra wide band wearable slot antenna with defected ground for WBAN applications 一种用于WBAN应用的新型柔性超宽带可穿戴带缺陷接地槽天线

IF 1.6 4区地球科学

Radio Science Pub Date : 2025-01-01 DOI: 10.1029/2024RS008085

Nageswara Rao Regulagadda;U. V. Ratna Kumari

引用次数: 0