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Wide Band RF ADC Conversion Artefacts and their Impact on Radio Astronomy 宽带射频ADC转换伪影及其对射电天文学的影响
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814198
J. Tuthill, P. Roberts, Samantha Gordon, G. Hobbs
{"title":"Wide Band RF ADC Conversion Artefacts and their Impact on Radio Astronomy","authors":"J. Tuthill, P. Roberts, Samantha Gordon, G. Hobbs","doi":"10.23919/AT-AP-RASC54737.2022.9814198","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814198","url":null,"abstract":"Current trends in state-of-the-art RF Analogue to Digital Converters (ADCs) indicate that their performance is approaching theoretical bounds imposed by the jitter noise of the supplied/distributed sample clock [1], [2]. In the first part of this paper, we show that ADC jitter noise, in the presence of strong, band-limited input signals, impacts the noise-floor performance of high-resolution ADCs which has a particularly harmful effect on pulsar radio astronomy. Furthermore, many of the current wide bandwidth RF ADCs typically rely on precise time-interleaving of several lower-rate ADCs to achieve high output resolution at the full Nyquist rate (see e.g. [3], [4]). In the second part of this paper, we present a new adaptive technique to mitigate the residual effects of time-interleaving artefacts from high-performance ADCs caused when strong, band-limited RFI is present at the converter input.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130673139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Non-invasive Measurement of Complex permittivity using a Compact Planar Microwave Sensor 基于紧凑平面微波传感器的复介电常数无创测量
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814367
Remsha Moolat, Manoj Mani, M. Pezholil
{"title":"Non-invasive Measurement of Complex permittivity using a Compact Planar Microwave Sensor","authors":"Remsha Moolat, Manoj Mani, M. Pezholil","doi":"10.23919/AT-AP-RASC54737.2022.9814367","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814367","url":null,"abstract":"This work describes the development of a compact planar microwave sensor for non-invasive complex permittivity measurement of liquids. The sensing element is a quarter wavelength stepped impedance resonator realized on an asymmetric coplanar stripline. To characterize the material, the sensor detects the resonance frequency and phase of the reflection coefficient. Numerical simulations were conducted for non-invasive and invasive measurements and mathematical relations are formulated for extracting the dielectric constant and loss tangent of the sample. The sensor is intended to operate at 5.6 GHz in free space. A prototype of the designed sensor is fabricated and tested with using a modest volume of test liquids as a proof of concept. The actual dielectric properties of the solution are measured using a commercially available dielectric probe. The extracted dielectric measurement acquired with the sensor are very similar to those obtained with the dielectric probe.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121168035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Variation of TEC Over South Africa During a Geomagnetic Storm 地磁风暴期间南非上空TEC的变化
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814299
T. Matamba, D. Danskin
{"title":"Variation of TEC Over South Africa During a Geomagnetic Storm","authors":"T. Matamba, D. Danskin","doi":"10.23919/AT-AP-RASC54737.2022.9814299","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814299","url":null,"abstract":"The ionosphere affects how radio waves propagate from the satellite to ground based receivers. During geomagnetic storms the Total Electron Content (TEC) varies due to the driving forces of the storm. The South African National Space Agency (SANSA) near-real time TEC map version 2 was used to show how the ionosphere varied during the geomagnetic storm of 19 - 23 Dec 2021. The Global Positioning System (GPS), ionosondes, and the quiet-time AFriTEC model were compared during the five day period. During the period of analysis, the Root Mean Squared Error (RMSE) were greater during the geomagnetic storm as compared with quiet days. The decrease in TEC were observed on 20 and 21 Dec 2021 during a geomagnetic storm period. The estimated TEC from the GPS and ionosode had similar temporal variations and magnitudes.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114690445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","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 Utilization of NARX for Antenna Array Adaptive Beamforming NARX在天线阵列自适应波束形成中的新应用
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814406
Ioannis Mallioras, Z. Zaharis, P. Lazaridis, N. Kantartzis, T. Yioultsis, Bo Liu, Stavros Kalafatis
{"title":"A Novel Utilization of NARX for Antenna Array Adaptive Beamforming","authors":"Ioannis Mallioras, Z. Zaharis, P. Lazaridis, N. Kantartzis, T. Yioultsis, Bo Liu, Stavros Kalafatis","doi":"10.23919/AT-AP-RASC54737.2022.9814406","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814406","url":null,"abstract":"In this paper, we investigate the use of a nonlinear autoregressive network with exogenous inputs (NARX) for adaptive beamforming on smart antennas. As a beamformer, NARX receives the angles of arrival of incoming signals to extract the complex feeding weights that produce the appropriate antenna radiation pattern. In order to demonstrate the potential of such an implementation, we test our model on a realistic linear antenna array composed of 16 microstrip elements. We use the null steering beamforming technique to produce the datasets needed for training and testing of our model and then we evaluate the accuracy of the radiation patterns produced by this model. To further demonstrate the efficiency of the NARX implementation, we also make a comparison with a feed-forward neural network that has the same architecture with that of NARX.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"23 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124500873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Wireless Sensor for Precision Grasping of Objects and Tools by Robotic Hands 用于机器人手精确抓取物体和工具的无线传感器
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814242
A. Gharibi, F. Costa, S. Genovesi
{"title":"Wireless Sensor for Precision Grasping of Objects and Tools by Robotic Hands","authors":"A. Gharibi, F. Costa, S. Genovesi","doi":"10.23919/AT-AP-RASC54737.2022.9814242","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814242","url":null,"abstract":"A preliminary study for a novel approach of detecting the orientation of a robotic hand with respect to non-metallic objects is illustrated. This goal is pursued by using a radiofrequency (RF) probe on the robotic hand and a printed resonator on the tagged item. In order to detect the hand orientation with respect to the target, the real part of the probe input impedance is examined for different angular orientations of the resonator placed on the object. The relation relating the oriented angle between the reader and the sensor to the impedance is addressed to define a proper calibration curve. A half wavelength dipole antenna as a probe on the hand and a metal strip (dipole resonator) placed on the object is employed. The sensing is performed within a near range distance from the object. As the result, it is observed that he proposed probe-resonator configuration allows the identification of the relative angular position of the hand with respect to the object with an encouraging level of accuracy.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124521083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Novel digital impedance bridges for the realization of the farad from graphene quantum standards 用于实现石墨烯量子标准的新型数字阻抗桥
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814423
M. Marzano, Y. Pimsut, M. Kruskopf, M. Kraus, M. Ortolano, S. Bauer, R. Behr, L. Callegaro
{"title":"Novel digital impedance bridges for the realization of the farad from graphene quantum standards","authors":"M. Marzano, Y. Pimsut, M. Kruskopf, M. Kraus, M. Ortolano, S. Bauer, R. Behr, L. Callegaro","doi":"10.23919/AT-AP-RASC54737.2022.9814423","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814423","url":null,"abstract":"In the International System of Units, a realization of the impedance units is the quantum Hall effect, a macroscopic quantum phenomenon that produces quantized resistance values. Established experiments employ individual GaAs devices [1], but research is ongoing on novel materials such as graphene, which allows the realization of the units with relaxed experimental conditions. Furthermore, novel digital impedance bridges allow the implementation of simple traceability chains. In the framework of the European EMPIR project 18SIB07 GIQS (Graphene Impedance Quantum Standards), an affordable and easy-to-operate impedance standard combining novel digital impedance bridges and graphene quantum standards has been developed. An onsite comparison of an electronic and a Josephson impedance bridges developed at INRIM (Istituto Nazionale di Ricerca Metrologica, Italy) and PTB (Physikalisch-Technische Bundesanstalt, Germany), respectively, were organized for their mutual validation and to assess their performance in the realization of the farad.Measurements of temperature-controlled impedance standards and of a graphene quantized Hall resistance standard in the AC regime were performed with both INRIM’s and PTB’s bridges. The result of the comparison and the last progresses of the GIQS project are here presented.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126245183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Anisotropic Time-varying Metasurface for Real-time Polarization Conversion 实时偏振转换的各向异性时变超表面
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814223
Q. Hu, Ke Chen, Yijun Feng
{"title":"Anisotropic Time-varying Metasurface for Real-time Polarization Conversion","authors":"Q. Hu, Ke Chen, Yijun Feng","doi":"10.23919/AT-AP-RASC54737.2022.9814223","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814223","url":null,"abstract":"Manipulating the polarization of electromagnetic waves is important for modern science and technology. Here, we propose an anisotropic time-varying metasurface for realizing dynamic conversion between input and output waves with different polarizations. The metasurface’s anisotropy can be dynamically tuned at will just by controlling the time-varying reflection phases of the metasurface for two orthogonally-polarized linear waves. A series of examples have been designed to verify polarization conversion among circular, linear, and even elliptical polarizations. The proposed method may provide a new way for versatile polarization manipulations that may have potential uses in many applications.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126247124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Satellite attitude effects on the reception of transionospheric HF signals: Examples from the Radio Receiver Instrument onboard e-POP/Swarm-E 卫星姿态对接收过渡层高频信号的影响:来自e-POP/Swarm-E机载无线电接收机的例子
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814292
E. C. K. Eyiguler, D. Danskin, G. Hussey, K. Pandey, Robert G. Gillies, A. Yau
{"title":"Satellite attitude effects on the reception of transionospheric HF signals: Examples from the Radio Receiver Instrument onboard e-POP/Swarm-E","authors":"E. C. K. Eyiguler, D. Danskin, G. Hussey, K. Pandey, Robert G. Gillies, A. Yau","doi":"10.23919/AT-AP-RASC54737.2022.9814292","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814292","url":null,"abstract":"The characteristics observed by an antenna onboard a spacecraft depend on the geometry between the receiving antenna and the electric fields of the radio wave. The antenna boresight direction should be along the transmitting source’s line-of-sight direction to be able to completely resolve the wave’s polarization characteristics. However, this is not always the case, especially for the antenna onboard a spacecraft due to the spacecraft orientation restrictions. Hence, in this study, the focus is on the antenna orientation effects on the observed polarization characteristics of the radio wave. Precise quaternion and sp3 orbit data of Swarm-E (formerly known as the CAScade, Smallsat, and Ionospheric Polar Explorer – CASSIOPE) spacecraft are used to determine the boresight of the Radio Receiver Instrument (RRI) onboard, for the coordinated experiments with the NRCAN-Ottawa transmitter (45.4oN, 75.6oW). The observed characteristics of the HF radio waves are determined for two selected cases with different attitude behavior: slew-to-target on 14 May 2017, and nadir mode on 11 August 2017. The effect of the angle between dipoles and radio wave propagation direction should be removed to resolve the physical characteristics of the wave.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125435916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Architecture of C-band Phased Array Feed with RFSoC digital beamformer 带RFSoC数字波束形成器的c波段相控阵馈电结构
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814401
A. Navarrini, A. Melis, G. Comoretto, T. Pisanu, R. Nesti, P. Marongiu, P. Ortu, P. Maxia, A. Ladu, H. Ghobadi, R. Concu, G. Angius, A. Cabras, L. Schirru, P. Di Ninni, M. Belluso, S. Billotta
{"title":"Architecture of C-band Phased Array Feed with RFSoC digital beamformer","authors":"A. Navarrini, A. Melis, G. Comoretto, T. Pisanu, R. Nesti, P. Marongiu, P. Ortu, P. Maxia, A. Ladu, H. Ghobadi, R. Concu, G. Angius, A. Cabras, L. Schirru, P. Di Ninni, M. Belluso, S. Billotta","doi":"10.23919/AT-AP-RASC54737.2022.9814401","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814401","url":null,"abstract":"We describe the architecture of a room-temperature C-band Phased Array Feed (PAF) demonstrator based on Radio Frequency System-on-Chip (RFSoC) for radio astronomy application. The instrument operates across the 4.75-6.00 GHz RF band (C-band). The RF section includes a compact module based on an 8×8 array of dual-polarization antennas integrated with MMIC (Monolithic Microwave Integrated Circuit) Low Noise Amplifiers (LNAs). A subset of 32 elements of one of the two polarization channels of the 128 antennas are connected to the LNAs, while the rest are terminated into internal loads. Following two stages of filtering and signal conditioning, the 32 RF signals are injected in two commercial RFSoC digital boards, each accepting 16 inputs with 1.25 GHz bandwidth, that will perform the frequency channelization, the partial and final beamforming of four independent beams with 1.25 GHz instantaneous bandwidth.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127971988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Design and Implementation of a Communications Circuit based on LoRa chip 基于LoRa芯片的通信电路设计与实现
2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC) Pub Date : 2022-05-29 DOI: 10.23919/AT-AP-RASC54737.2022.9814172
J. Monzón-Monedero, V. Araña, F. Cabrera, P. Dorta
{"title":"Design and Implementation of a Communications Circuit based on LoRa chip","authors":"J. Monzón-Monedero, V. Araña, F. Cabrera, P. Dorta","doi":"10.23919/AT-AP-RASC54737.2022.9814172","DOIUrl":"https://doi.org/10.23919/AT-AP-RASC54737.2022.9814172","url":null,"abstract":"Forest fires are one of the main threats nowadays due to the consequences they have for the society and economy. During a wildfire, to obtain information about the status and evolution of the flames, communications systems become a key aspect in extinguishing the flames.These communications systems must provide real-time information to be useful. For getting the real-time feature, the sensors which obtain the data must be easy to deploy. This way, the sensors and the communications system will be carried by light mobile units. The communications protocols suitable for light mobile units work in high frequency bands.However, under rural environmental conditions, these bands have critical fading due to a high vegetation density and the orography. To avoid this fading, a design, and an implementation of a VHF (Very High Frequency) header for a LoRa (Long Range) chip has been presented and implemented in this paper.","PeriodicalId":356067,"journal":{"name":"2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130250582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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