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1
Perov, Sergey Yu, e Olga V. Belaya. "Electromagnetic environment created by mobile communication base stations in the 5G pilot area". Hygiene and sanitation 102, n. 6 (28 luglio 2023): 538–43. http://dx.doi.org/10.47470/0016-9900-2023-102-6-538-543.
Abstract (sommario):
Introduction. In the context of 5G system integration for general public, the change of electromagnetic field background is expected. The electromagnetic field background will change in spectral composition, spatial and temporal distribution, which affects the methodological approaches of instrumental control and hygienic assessment.
Materials and methods. In the 5G pilot area the frequency-selective, code-selective and broadband measurements were carried out for the actual and possible electromagnetic field assessment from GSM, UMTS, LTE and 5G/IMT-2020 base station at several points.
Results. The research results have shown that the actual electromagnetic levels did not exceed 1.5 μW/cm2, the main part of actual (measured) level includes GSM and LTE base stations (1800 MHz). At some points, the main part of maximum possible electromagnetic field exposure did not exceed 8.5 μW/cm2 and created by the 5G/IMT-2020 traffic transmission beam from base station to the subscriber terminal.
Limitations. The limitation of study is determined by the measurement conditions of 5G/IMT-2020 test operation modes in the pilot area, it is difficult to assess the actual EMF exposure from commercial networks user service.
Conclusion. In the intensive progress of mobile communication, the frequency- and code-selective measuring instruments are necessary to improve approaches for instrumental control and evaluation for electromagnetic fields from various mobile communication, especially for 5G assessment.
2
Deprez, Kenneth, Loek Colussi, Erdal Korkmaz, Sam Aerts, Derek Land, Stephan Littel, Leen Verloock, David Plets, Wout Joseph e John Bolte. "Comparison of Low-Cost 5G Electromagnetic Field Sensors". Sensors 23, n. 6 (21 marzo 2023): 3312. http://dx.doi.org/10.3390/s23063312.
Abstract (sommario):
This paper compares different low-cost sensors that can measure (5G) RF-EMF exposure. The sensors are either commercially available (off-the-shelf Software Defined Radio (SDR) Adalm Pluto) or constructed by a research institution (i.e., imec-WAVES, Ghent University and Smart Sensor Systems research group (S³R), The Hague University of Applied Sciences). Both in-lab (GTEM cell) and in-situ measurements have been performed for this comparison. The in-lab measurements tested the linearity and sensitivity, which can then be used to calibrate the sensors. The in-situ testing confirmed that the low-cost hardware sensors and SDR can be used to assess the RF-EMF radiation. The variability between the sensors was 1.78 dB on average, with a maximum deviation of 5.26 dB. Values between 0.09 V/m and 2.44 V/m were obtained at a distance of about 50 m from the base station. These devices can be used to provide the general public and governments with temporal and spatial 5G electromagnetic field values.
3
Kim, Seungmo, e Imtiaz Nasim. "Human Electromagnetic Field Exposure in 5G at 28 GHz". IEEE Consumer Electronics Magazine 9, n. 6 (1 novembre 2020): 41–48. http://dx.doi.org/10.1109/mce.2019.2956223.
4
Perov, Sergey Yu, Olga V. Belaya, Quirino Balzano e Nina B. Rubtsova. "The problems of mobile communication electromagnetic field exposure assessment today and tomorrow". Russian Journal of Occupational Health and Industrial Ecology 60, n. 9 (7 ottobre 2020): 597–99. http://dx.doi.org/10.31089/1026-9428-2020-60-9-597-599.
Abstract (sommario):
New and necessary improvements of electromagnetic exposure assessment principles and methods are considered and presented. The electromagnetic field exposure assessment is the physical basis for hygienic and biological research and needs s to consider the new technological features of emerging 5G mobile systems in addition to existing 2-4G systems. The new generation of telecommunication networks will cause significantly novel electromagnetic field exposure, in particular for time-frequency and spatial parameters. A complex exposure assessment based on refined broadband measurements seems to be the proper and necessary approach to the enhancement of Russian EMF assessment guidelines. Simple broadband EMF measurements are the common approach for present exposure assessment and cannot be used any longer as the only measure for multiple 5G sources exposure evaluation. Then again broadband measurements are the simple and practical approach for mm wave in-situ exposure assessment. Frequency-selective and code-selective measurements provide detailed EMF level distribution in separate frequency channels, telecommunication services or sources and are a promising approach for objective exposure assessment.
5
Frank, John William. "Electromagnetic fields, 5G and health: what about the precautionary principle?" Journal of Epidemiology and Community Health 75, n. 6 (19 gennaio 2021): 562–66. http://dx.doi.org/10.1136/jech-2019-213595.
Abstract (sommario):
New fifth generation (5G) telecommunications systems, now being rolled out globally, have become the subject of a fierce controversy. Some health protection agencies and their scientific advisory committees have concluded that there is no conclusive scientific evidence of harm. Several recent reviews by independent scientists, however, suggest that there is significant uncertainty on this question, with rapidly emerging evidence of potentially harmful biological effects from radio frequency electromagnetic field (RF-EMF) exposures, at the levels 5G roll-out will entail. This essay identifies four relevant sources of scientific uncertainty and concern: (1) lack of clarity about precisely what technology is included in 5G; (2) a rapidly accumulating body of laboratory studies documenting disruptive in vitro and in vivo effects of RF-EMFs—but one with many gaps in it; (3) an almost total lack (as yet) of high-quality epidemiological studies of adverse human health effects from 5G EMF exposure specifically, but rapidly emerging epidemiological evidence of such effects from past generations of RF-EMF exposure; (4) persistent allegations that some national telecommunications regulatory authorities do not base their RF-EMF safety policies on the latest science, related to unmanaged conflicts of interest. The author, an experienced epidemiologist, concludes that one cannot dismiss the growing health concerns about RF-EMFs, especially in an era when higher population levels of exposure are occurring widely, due to the spatially dense transmitters which 5G systems require. Based on the precautionary principle, the author echoes the calls of others for a moratorium on the further roll-out of 5G systems globally, pending more conclusive research on their safety.
6
Mallik, Mohammed, Angesom Ataklity Tesfay, Benjamin Allaert, Redha Kassi, Esteban Egea-Lopez, Jose-Maria Molina-Garcia-Pardo, Joe Wiart, Davy P. Gaillot e Laurent Clavier. "Towards Outdoor Electromagnetic Field Exposure Mapping Generation Using Conditional GANs". Sensors 22, n. 24 (9 dicembre 2022): 9643. http://dx.doi.org/10.3390/s22249643.
Abstract (sommario):
With the ongoing fifth-generation cellular network (5G) deployment, electromagnetic field exposure has become a critical concern. However, measurements are scarce, and accurate electromagnetic field reconstruction in a geographic region remains challenging. This work proposes a conditional generative adversarial network to address this issue. The main objective is to reconstruct the electromagnetic field exposure map accurately according to the environment’s topology from a few sensors located in an outdoor urban environment. The model is trained to learn and estimate the propagation characteristics of the electromagnetic field according to the topology of a given environment. In addition, the conditional generative adversarial network-based electromagnetic field mapping is compared with simple kriging. Results show that the proposed method produces accurate estimates and is a promising solution for exposure map reconstruction.
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Franci, Daniele, Stefano Coltellacci, Enrico Grillo, Settimio Pavoncello, Tommaso Aureli, Rossana Cintoli e Marco Donald Migliore. "Experimental Procedure for Fifth Generation (5G) Electromagnetic Field (EMF) Measurement and Maximum Power Extrapolation for Human Exposure Assessment". Environments 7, n. 3 (17 marzo 2020): 22. http://dx.doi.org/10.3390/environments7030022.
Abstract (sommario):
The fifth generation (5G) technology has been conceived to cover multiple usage scenarios from enhanced mobile broadband to ultra-reliable low-latency communications (URLLC) to massive machine type communications. However, the implementation of this new technology is causing increasing concern over the possible impact on health and safety arising from exposure to electromagnetic field radiated by 5G systems, making imperative the development of accurate electromagnetic field (EMF) measurement techniques and protocols. Measurement techniques used to assess the compliance with EMF exposure limits are object to international regulation. The basic principle of the assessment is to measure the power received from a constant radio frequency source, typically a pilot signal, and to apply a proper extrapolation factor. This kind of approach is standardized for 2G, 3G, and 4G technologies, but is still under investigation for 5G technology. Indeed, the use of flexible numerologies and advanced Time Division Duplexing (TDD) and spatial multiplexing techniques, such as beam sweeping and Massive Multiple Input Multiple Output (MIMO), requires the definition of new procedures and protocols for EMF measurement of 5G signals. In this paper a procedure for an accurate estimation of the instant maximum power received from a 5G source is proposed. The extrapolation technique is based on the introduction of proper factors that take into account the effect of the TDD and of the sweep beam in the measured value of the 5G signal level. Preliminary experimental investigation, based on code domain measurement of appropriate broadcast channels, and carried out in a controlled environment are reported, confirming the effectiveness of the proposed approach.
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Akdoğan, Hilmi, Vasil Tabatadze, Kamil Karaçuha e Ercan Yaldiz. "Several case studies on electric field distributions for two human bodies inside the car at 3.5 GHz–5G frequency band". International Journal of Applied Electromagnetics and Mechanics 67, n. 4 (9 dicembre 2021): 507–20. http://dx.doi.org/10.3233/jae-210035.
Abstract (sommario):
The study investigates basically, the electric field distribution in a semi-closed region. Specifically, the present work focuses on the electromagnetic wave diffraction at 3.5 GHz in the vicinity of a car where two humans are located inside. The car is modeled as the perfect electric conducting object whereas the human bodies are assumed to be homogeneous lossy dielectrics. To obtain field distributions for different sceneries, the Method of Auxiliary Sources (MAS) is employed. To achieve this goal, the auxiliary sources due to each obstacle are distributed over the corresponding surface element. In the present study, two main different scenarios are considered. One or two cellphones as the source of electromagnetic waves are considered. These cellphones are operating at the proposed 5G frequency band in the European Zone. In this frequency range, the resonances are observed at 3.5 GHz which is in the range of a planned 5G communication frequency band. The present study aims to obtain quantitative and qualitative results for a better understanding of 5G healthy issues. Therefore, as a frontier study, the specific absorption rate (SAR) values are examined for the first time to answer some important questions related to 5G. For such a scenario, MAS is a very efficient, fast, and trustworthy approach to obtain field distribution at semi-closed regions.
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Nascimento, Luiz F. C., Galdenoro Botura Jr. e Rogério P. Mota. "Glucose consume and growth of E. coli under electromagnetic field". Revista do Instituto de Medicina Tropical de São Paulo 45, n. 2 (aprile 2003): 65–67. http://dx.doi.org/10.1590/s0036-46652003000200002.
Abstract (sommario):
E. coli was submitted to a 5G electromagnetic field generated by a alternate 60 Hz voltage source. The differences on growth and glucose consume in control and exposed groups were evaluated using the non-parametric Mann-Whitney U-test. There was a significant difference in glucose consume and growth in E. coli after 8 hours of exposition to electromagnetic field. It can be concluded that electromagnetic field had a positive effect in consume of glucose and growth of E. coli. The cause of these results can be explained by an increasing of glucose entrance through membrane due to the stimulated transport system via Facility Diffusion or cyclotron resonance. The growth can be caused by shortening of lag phase and excitement of log phase.
10
Ahmed Salem, Mohammed, Heng Siong Lim, Ming Yam Chua, Khaled Abdulaziz Alaghbari, Charilaos Zarakovitis e Su Fong Chien. "Assessing electromagnetic field exposure levels in multi-active reconfigurable intelligent surface assisted 5G network". International Journal of Electrical and Computer Engineering (IJECE) 14, n. 4 (1 agosto 2024): 4110. http://dx.doi.org/10.11591/ijece.v14i4.pp4110-4119.
Abstract (sommario):
As 5G mobile networks continue to proliferate in dense urban environments, it becomes increasingly important to understand and mitigate excessive electromagnetic field (EMF) exposure. This study investigates how the downlink EMF exposure levels of 5G millimeter wave (mm-wave) mobile networks are influenced by the integration of multi-active reconfigurable intelligent surfaces (RISs), using a ray-tracing approach. Our research employs a comprehensive two-step methodology: Firstly, we introduce a new RIS-assisted 5G mm-wave network planning technique. This technique leverages a machine learning (ML) approach for the classification of multi-RIS clusters. The primary goal is to optimize coverage while minimizing the number of required RIS deployments. This is achieved by strategically placing RISs based on the ML classification, ultimately aiming to enhance network efficiency. Secondly, we conducted a thorough comparative analysis, evaluating the impact of both passive and active RISs on EMF exposure level throughout a dense urban environment. Passive RIS and active RIS differ in their adaptability to changing network conditions. The result shows that the influence of multi-active RISs on EMF exposure is significant (about 7.5 times higher) compared to passive RISs.
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Tabatadze, Vasil, Kamil Karaçuha, Eldar Veliyev, Ertuğrul Karaçuha e Revaz Zaridze. "The Electric Field Calculation for Mobile Communication Coverage in Buildings and Indoor Areas by Using the Method of Auxiliary Sources". Complexity 2020 (8 aprile 2020): 1–8. http://dx.doi.org/10.1155/2020/4563859.
Abstract (sommario):
In this article, the diffraction of the electromagnetic wave by the building with two rooms is considered. The rooms have doors and windows with lossy dielectric walls. The electromagnetic properties of the building as an opened coupled resonator system are investigated at different source locations and several frequencies including 5G band. The problem is solved by using the Method of Auxiliary Sources. The near electric field distributions are calculated and analyzed.
12
Tasneem Sofri, Hasliza A Rahim, Allan Melvin Andrew, Ping Jack Soh, Latifah Munirah Kamarudin e Nishizaki Hiromitsu. "Data Normalization Methods of Hybridized Multi-Stage Feature Selection Classification for 5G Base Station Antenna Health Effect Detection". Journal of Advanced Research in Applied Sciences and Engineering Technology 30, n. 2 (5 aprile 2023): 133–40. http://dx.doi.org/10.37934/araset.30.2.133140.
Abstract (sommario):
It is essential to assess human exposure to Fifth Generation (5G) Radiofrequency Electromagnetic Field (RF-EMF) signal from Base Station (BS) sources operating at Low Band 5G at 700 MHz, Sub-6 Band 5G at 3.5 GHz, and Millimeter Wave (mmWave) 5G at 28 GHz. This assessment will help determine whether 5G technology is safe for people. Inconsistent results were found in previous epidemiological studies on the health effects of radiation exposure from Mobile Phones (MP) and BS when normalization methods were used to prepare the data for Machine Learning (ML), which could lead to misclassification because of the dataset's quality. The effects on adult health are assessed in terms of physiological parameters (body temperature, heart rates, and blood pressure), cognitive performance (brain memory, motor control, and attention), Visual Analogue Scales (VAS) for well-being parameter, and Electromagnetic Field (EMF) perception parameter. The purpose of the research was to identify changes in the physiological parameters of adult individuals before, during, or after exposure to 5G signals, including Sham (No Exposure). 12 normalization methods are selected which are Z-score normalization (z score), Linear scaling (LS), Binary normalization (BNN), Bipolar normalization (BPN), Min-Max scaling (MMS), t-score normalization (t score), Decimal Inverse Logarithmic Scaled Normalization (DILSN), Relative Mean Normalization (RMN), Relative Standard Deviation Normalization (RSDN), Variation Normalization (VN), Robust Normalization (RN) and Relative Interquartile Normalization (RIN) and based on their F-value and p-value analyses, the three best normalization techniques are selected in this research. The original distribution of each parameter data variable is different, these techniques are beneficial for converting data so that it is dimensionless and has equivalent distributions. Based on the selection criteria for the hybridized Multi-Stage Feature Selection (MSFS) classification for 5G base station antenna health effect detection, BNN, MMS, and RSDN were named as the top three normalization techniques.
13
Ursăchianu, M. V., C. Lăzărescu, O. Bejenaru e A. Sălceanu. "Assessment of human exposure to EMF generated by 5G mobile phone base stations". IOP Conference Series: Materials Science and Engineering 1254, n. 1 (1 settembre 2022): 012026. http://dx.doi.org/10.1088/1757-899x/1254/1/012026.
Abstract (sommario):
Abstract The paper presents a preliminary survey over human exposure to radiofrequency (RF) electromagnetic field (EMFs) levels generated in the vicinity of the new 5G mobile phone base stations recently installed in different major cities in Romania in comparison with other different frequency bands already used for mobile phone base stations. Measurement of electromagnetic field levels has been performed in Iasi, one of the major cities of Romania. Measurements have been performed in different urban locations with a high density of mobile phone base stations (from national operators). The EMF exposure levels for different mobile communications technologies have been measured with a calibrated up to date NARDA SRM 3006 field strength analyser system connected to an isotropic electric field probe. The methodology described by ECC RECOMMENDATION (02)04 has been rigorously respected.
14
Yang, Zhichao, Dong Dang, Xu Cheng, Juan Mo, Xiaoyu Zhou, Yuqun Fang e Yong Peng. "Analysis of Electromagnetic Radiation of Mobile Base Stations Co-located with High-Voltage Transmission Towers". Symmetry 15, n. 6 (13 giugno 2023): 1252. http://dx.doi.org/10.3390/sym15061252.
Abstract (sommario):
This paper presents the analysis of electromagnetic radiation of mobile base stations co-located with high-voltage transmission towers. Although the layout of power poles and towers is uniform and symmetrical, the electromagnetic field radiated to the outside world is asymmetric. Field measurements were conducted in different co-located base station scenarios, and the field strength results in both the vertical and horizontal directions were analyzed in depth. Then, the ray tracing simulation method was used to obtain the electromagnetic field distribution characteristics for the 5G base station co-located high-voltage tower. Finally, the specific absorption rate (SAR) was adopted to evaluate human exposure in co-located base station scenarios, and a physical area-based human exposure assessment method proposed. The obtained results can be useful for inspectors of mobile base stations co-located with high-voltage transmission towers to avoid or reduce the impact of electromagnetic radiation.
15
Franci, Daniele, Stefano Coltellacci, Enrico Grillo, Settimio Pavoncello, Tommaso Aureli, Rossana Cintoli e Marco Donald Migliore. "An Experimental Investigation on the Impact of Duplexing and Beamforming Techniques in Field Measurements of 5G Signals". Electronics 9, n. 2 (29 gennaio 2020): 223. http://dx.doi.org/10.3390/electronics9020223.
Abstract (sommario):
The fifth generation mobile network introduces dramatic improvements with respect to the previous technologies. Features such as variable numerology, bandwidth parts, massive Multiple Input Multiple Output (MIMO) and Time Division Duplex (TDD) will extend the capabilities of the 5G wireless systems and, at the same time, will influence the measurement techniques used to assess the compliance with general public electromagnetic field exposure limits. In this study, a heterogeneous set of 5G signals is investigated with the aim of establishing an effective measurement technique suitable for the new technology. Following an experimental approach based on both modulation and zero span analysis, some important characteristics of the 5G system are highlighted and extensively discussed, and experimental procedures for estimating factors associated to TDD (F T D C factor) and beam sweeping (R factor), to be used in the extrapolation formulas, are presented. The results of this study represent a starting point for future investigations on effective methods to estimate both the instant maximum power and the total power transmitted during a 5G radio frame.
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Moshood, Taofeeq D., e Rukayat A. Shittu. "Covid-19 and 5G Radiation are Two Parallel Lines: A Systematic Review". International Journal of Innovative Science and Research Technology 5, n. 7 (1 agosto 2020): 744–51. http://dx.doi.org/10.38124/ijisrt20jul597.
Abstract (sommario):
The rapid dissemination of new coronaviruses worldwide in 2019–2020 has had a significant effect on global economic and social growth. Those exchanges have featured numerous conspiracies spread by patrons on social media. Among them, 5G has been related by a common hypothesis to the dissemination of COVID-19, which has contributed to confusion and the destruction of 5G towers in the UK. Understanding the drivers of false news and swift strategies aimed at isolating and rebating disinformation is crucial to combating it. This paper sought a systematic literature review to save, classify, and interpret the evidence for this research. A total of 95 articles have been successfully reviewed, consisting of 50 Scopus journals and 45 conference papers ranging from the publication years (2014 to 2020). The primary purpose of this study is to investigate the effects of electromagnetic fields on the human body and to clarify health laws in general public and industrial radiation. The knowledge on the electromagnetic field was obtained using instruments to determine the sensitivity amount of some of the home appliances in the magnetic and electric fields.
17
Schneider, Birgit. "Camouflaging Electromagnetic Networks as Techno-Habitats for Humans, Plants, Animals, and Machines". Cultural Politics 20, n. 1 (1 marzo 2024): 166–79. http://dx.doi.org/10.1215/17432197-10969297.
Abstract (sommario):
Abstract “Digitalization is coming” is the mantra of our society. In recent decades, the environment has been transformed into a high-frequency electromagnetic field by the increasing number of antennas. At present, the roll-out of the new generation of 5G wireless networks means that urban spaces will be littered with thousands of new antennas, invisibly hidden in all sorts of housings such as street lamps, advertising pillars, and neon signs. This development is not stopping at the countryside either. This essay uses media theory and examples from art and technology to speculate on how the changes in urban space and atmosphere can be understood, but also why 5G is a perfect case for techno-criticism and conspiracy theories alike. The waves of wireless networks are spreading to reach even the smallest niches, driven by mobile telephony and wireless Internet. In the future, the environment in which we are immersed and which pervades us will always be an electric field flowing through us. Like any other radio network, 5G is invisible and abstract, and no one can see the artificially generated high-frequency radiation. At the same time, almost all of us have a sensor in our pocket with our mobile phone, telling us where the network is and how strong the radiation is.
18
Migliore, M. D. "5G Field level measurement for human exposure assessment: A lesson for 6G". IOP Conference Series: Materials Science and Engineering 1254, n. 1 (1 settembre 2022): 012001. http://dx.doi.org/10.1088/1757-899x/1254/1/012001.
Abstract (sommario):
Abstract Field level measurement for human exposure assessment is an important and sometimes underestimated problem. The aim of this work is to describe the problem of field level measurement for the assessment of human exposure from 2G to 5G, showing the growing difficulties caused by an increasing flexibility of cellular communication systems. If on the one hand this flexibility allowed higher performances, on the other hand it made the estimation of the electromagnetic field more and more complex. 5G field level measurement for human exposure assessment represents a formidable complex problem, currently under study to identify reliable and low-cost methods. Vendors have recently understood this problem and have included a control on the power density radiated by antennas in 5G systems, known as the ”power lock” function. It is worth noting that for the first time a sophisticated power control is introduced in base stations (BS) for the human exposure target. This should be a lesson for the development of 6G, suggesting a safety-on-design approach to human exposure for the next generation of personal communication systems.
19
Abdimuratov, Zh S., Zh D. Manbetova, M. N. Imankul, K. S. Chezhimbayeva e A. Zh Sagyndikova. "METHODS FOR PROTECTING THE EQUIPMENT OF CELLULAR (MOBILE) CONNECTION FROM ELECTROMAGNETIC IMPACT". PHYSICO-MATHEMATICAL SERIES 335, n. 1 (10 febbraio 2021): 81–89. http://dx.doi.org/10.32014/2021.2224-5294.12.
Abstract (sommario):
Under electromagnetic impact (EMI) of a sufficient level, temporary disruption of functioning, processing, transmission and storage of information in cellular equipment is possible. Possible problems of electromagnetic compatibility (EMC) of a mobile phone and a base station (BS) of cellular connection under the influence of electromagnetic radiation (EMR) from other sources and their negative impact on functioning are considered. The energy of the HF electromagnetic field (EMF) after passing through the protective case can affect the devices of shielded radio electronic equipment (REE), therefore, the possible negative consequences of the impact of high-energy EMF on the REE are described. Possible negative consequences under certain conditions from the influence of the skin-effect, the effects of electrostatic discharge and electromagnetic pulses on electronic devices are given. It is shown that the constructional method of protecting REE from the effects of external electromagnetic factors consists in reducing the collected and transmitted EMF energy by improving the design, placement and installation of equipment. Components of some vendors for 5G systems that are resistant to external interference are given, and the possibilities for reducing the radiation level of a cell phone are noted. The necessity of an integrated approach to solving EMC problems is substantiated, which consists in the use of structural, circuitry and structural-functional methods of EMC provision. The new 5G (Fifth Generation) standard will operate at higher operating frequencies compared to previous generations. Due to the workload of the electromagnetic spectrum at frequencies below 6 GHz, 5G networks will be based on wireless radio access systems operating at frequencies of 30–100 GHz, that is, in the lower band of the extremely high frequency range EHF (Extremely High Frequency), 30–300 GHz.
20
Abdimuratov, Zh S., Zh D. Manbetova, M. N. Imankul, K. S. Chezhimbayeva e A. Zh Sagyndikova. "METHODS FOR PROTECTING THE EQUIPMENT OF CELLULAR (MOBILE) CONNECTION FROM ELECTROMAGNETIC IMPACT". PHYSICO-MATHEMATICAL SERIES 335, n. 1 (8 febbraio 2021): 81–89. http://dx.doi.org/10.32014/2021.2518-1726.12.
Abstract (sommario):
Under electromagnetic impact (EMI) of a sufficient level, temporary disruption of functioning, processing, transmission and storage of information in cellular equipment is possible. Possible problems of electromagnetic compatibility (EMC) of a mobile phone and a base station (BS) of cellular connection under the influence of electromagnetic radiation (EMR) from other sources and their negative impact on functioning are considered. The energy of the HF electromagnetic field (EMF) after passing through the protective case can affect the devices of shielded radio electronic equipment (REE), therefore, the possible negative consequences of the impact of high-energy EMF on the REE are described. Possible negative consequences under certain conditions from the influence of the skin-effect, the effects of electrostatic discharge and electromagnetic pulses on electronic devices are given. It is shown that the constructional method of protecting REE from the effects of external electromagnetic factors consists in reducing the collected and transmitted EMF energy by improving the design, placement and installation of equipment. Components of some vendors for 5G systems that are resistant to external interference are given, and the possibilities for reducing the radiation level of a cell phone are noted. The necessity of an integrated approach to solving EMC problems is substantiated, which consists in the use of structural, circuitry and structural-functional methods of EMC provision. The new 5G (Fifth Generation) standard will operate at higher operating frequencies compared to previous generations. Due to the workload of the electromagnetic spectrum at frequencies below 6 GHz, 5G networks will be based on wireless radio access systems operating at frequencies of 30–100 GHz, that is, in the lower band of the extremely high frequency range EHF (Extremely High Frequency), 30–300 GHz.
21
Kwon, DukSoo, Young Seung Lee, Chang-Hee Hyoung, Jung-Hwan Hwang e Hyung-Do Choi. "Loop-Type Field Probe to Measure Human Body Exposure to 5G Millimeter-Wave Base Stations". Applied Sciences 13, n. 21 (27 ottobre 2023): 11777. http://dx.doi.org/10.3390/app132111777.
Abstract (sommario):
This paper proposes a field probe to measure the power density (PD) at a millimeter-wave (mmWave) frequency band. The proposed probe is composed of a loop antenna in which one end is terminated with a load resistor. Such a structure enables the simultaneous measurement of electric (E)- and magnetic (H)-fields: the E-field is measured at a gap where the load resistor is placed, and the H-field is measured through the loop antenna. The simultaneous measurement makes it possible to measure PD for an incident wave even in the near field region where the E- and H-fields have different phases from each other. The proposed probe is fabricated and evaluated for its PD measurement performance. The measurement results show that the probe measures PD with an error less than 1.3 dB. Owing to the near field measurement, the proposed probe is useful in measuring the human body exposure to electromagnetic fields (EMFs) that are generated by 5G mmWave base stations.
22
Yekeh Yazdandoost, Kamya, e Ilkka Laakso. "NUMERICAL MODELING OF ELECTROMAGNETIC FIELD EXPOSURE FROM 5G MOBILE COMMUNICATIONS AT 10 GHZ". Progress In Electromagnetics Research M 72 (2018): 61–67. http://dx.doi.org/10.2528/pierm18070503.
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Makhmanazarov, Ramdas, Ilya Tseplyaev, Sergey Shipilov e Natalya Krivova. "Estimation of SAR Average in Rats during 5G NR Chronic Exposure". Applied Sciences 14, n. 1 (26 dicembre 2023): 208. http://dx.doi.org/10.3390/app14010208.
Abstract (sommario):
To study physiological reactions in the brain and skin of higher mammals exposed to chronic radiofrequency radiation, specific absorption ratio (SAR) determination is required and time-consuming numerical methods are used. The paper deals with the estimation of the whole-body specific absorption rate (SAR) in rats chronically exposed to external electromagnetic fields, as well as the development of a laboratory setup simulating the operation of a fifth-generation 5G New Radio base station (with a signal bandwidth of 15 MHz and a carrier frequency of 2.4 GHz). The paper presents a modified method for theoretical SAR estimation for one-sided irradiation and distributed absorption. Mean whole-body SAR values were estimated by the proposed method and numerically modeled with the CST Microwave Studio simulation software 2020package using primitive rat models. Dielectric parameters in the numerical simulation were used from the software library. The IEEE/IEC 62704-1 algorithm was used to investigate SAR in numerical simulations. The theoretical estimates and numerical simulations were compared for different SAR distributions and were found to be qualitatively comparable. The differences between approximate theoretical estimates and numerical simulations are 7% and 10% for distributed and non-distributed absorptions, respectively. The proposed method, which takes into account the decreasing power flux density, can be used to estimate the approximate whole-body SAR during chronic electromagnetic field exposure in rats.
24
Deaconescu, Delia Bianca, e Simona Miclaus. "The 5G-FR1 Signals: Beams of the Phased Antennas Array and Time-Recurrence of Emissions with Consequences on Human Exposure". Electronics 12, n. 2 (6 gennaio 2023): 297. http://dx.doi.org/10.3390/electronics12020297.
Abstract (sommario):
The fifth generation (5G) of mobile communication technology poses lots of questions while introducing significant improvements compared with previous generations. The most sensitive question is related to the safety of human exposure. The aim of present work was to analyze, with a few chosen examples, two of the most significant features of 5G emissions: the extreme spatial variability of the exposure and the nonlinear dynamics characteristics of the temporal variability of the exposure. Two models of patch antenna arrays operating at 3.7 GHz with varying beam forming and beam steering capabilities were considered for an analysis of the specific absorption rate of electromagnetic energy deposition in tissues of a head model. This allowed clear emphasis on the influence of the antenna geometry and feeding peculiarities on the spatial variability of exposure. The second approach implemented the original idea of following the nonlinear recurrence behavior of exposure in time, and underlined the time variability characteristics of emissions with a real-life mobile phone running different 5G applications. Time series of the emitted electric-field strengths were recorded by means a real-time spectrum analyzer and two near-field probes differently positioned in the beam. The presence of laminar emissions, chaotic emissions, determinism and recurrence in the exposures prove the potential for recurrence quantification in predicting time variability features of 5G exposure. Overall, the impact of 5G signals on living bodies, with the highest possible man-made spatial and temporal variability, may have very unpredictable bio-medical consequences.
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Cui, Wuwei. "Modern Electromagnetic Field Theory and Its Application in Future Wireless Communication". Journal of Physics: Conference Series 2386, n. 1 (1 dicembre 2022): 012044. http://dx.doi.org/10.1088/1742-6596/2386/1/012044.
Abstract (sommario):
Abstract With the advent of the 5G era, more and more technologies in life are applied to the technological development and theory of antennas. Waveform constraints. These basic applications are obtained due to the natural seismic source and the continuous arrangement and combination of arrays. In this article, we first discuss the spherically symmetric electric field distribution of antenna elements in space, and then discuss the influence of a circular array on the electromagnetic intensity of the space radiated field. At the same time, the basic characteristics of waveform restraint, array radar and array telescope are discussed. Afterwards, from a theoretical point of view, the physical properties and radiation characteristics of the near-field induction field and radiation field of the factory around the vibrator were analyzed quantitatively and qualitatively. Later, I discussed the relationship between an annular array and the eddy current. Through theoretical derivation and excitation factors, we used the original radiation equation to derive the Bessel function, and used a computer to make a simulation to explore the factors that can affect the array radiation.
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Kamarudin, Saidatul Izyanie, Alyani Ismail, Aduwati Sali, Mohd Yazed Ahmad, Ismayadi Ismail e Keivan Navaie. "5G Magnetic Resonance Coupling Planar Spiral Coil Wireless Power Transfer". Trends in Sciences 20, n. 1 (24 novembre 2022): 3444. http://dx.doi.org/10.48048/tis.2023.3444.
Abstract (sommario):
Wireless Power Transfer in the 5G frequency band is the most promising technology to power up ubiquitous small electronic devices as well as IoT devices. A strongly coupled magnetic resonance WPT technique that focuses on near-field electromagnetic energy has been proposed in this paper. However, most Magnetic Resonance Coupling Wireless Power Transfer (MRC WPT) applications have been designed in kHz and MHz frequency spectrum. This paper demonstrates Planar Spiral Coil Magnetic Resonance Coupling (PSC MRC) WPT designs at 5G (GHz) frequencies. Also, the transformation technique of the low frequency (kHz and MHz) magnetic resonance circuit model equations to high frequency (GHz) circuit model equations to achieve a high-efficiency power transfer. PSC MRC WPT designs structure antennas are designed at 3.4 - 3.5 GHz in the form of circular and square shapes with 1 turn coil. The proposed antenna structures are firstly being optimized in a full-wave electromagnetic simulator, CST Microwave Studio to resonate at the 3.4 - 3.5 GHz band. Then, the close-loop equations to determine the efficiency of 5G Magnetic Resonance Coupling Planar Spiral Coil Wireless Power Transfer is designed. Lastly, the results are compared with the simulation and calculated parts. The highest efficiency of the PSC MRC circular antenna is 31.58 % when the distance is at 2 mm, and 31.26 and 31.02 % when the distance is at 3 and 4 mm, respectively. The efficiency of circular PSC MRC is found to be 25 % better than the efficiency of square shape design. HIGHLIGHTS IoT devices need to be charged and maintained as the network system has massive numbers of sensors. Wireless power transfer is a promising technology to power up IoT devices This paper proposed, a WPT technique based on strongly coupled magnetic resonance which focuses on the near-field electromagnetic energy. This technique can extend the distance of the power transfer between the transmitter and the receiver The transformation technique of the low frequency (kHz and MHz) magnetic resonance circuit model equations to high frequency (GHz) circuit model equations to achieve a high-efficiency PSC MRC WPT design structure is introduced in this paper This novel technique can be applied to effectively design PSC MRC Antenna WPT for 5G applications. Most reported Magnetic Resonance Coupling Wireless Power Transfer (MRC WPT) applications have been designed in kHz and MHz frequency spectrum GRAPHICAL ABSTRACT
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Atanasova, Gabriela Lachezarova, Blagovest Nikolaev Atanasov e Nikolay Todorov Atanasov. "Assessment of Electromagnetic Field Exposure on European Roads: A Comprehensive In Situ Measurement Campaign". Sensors 23, n. 13 (30 giugno 2023): 6050. http://dx.doi.org/10.3390/s23136050.
Abstract (sommario):
The rapid evolution of wireless communication technologies (such as fifth-generation (5G) cellular networks) in the last years has allowed connecting different objects (from wearable electronics to vehicles) and people through communication networks, and at the same time, has led to widespread deployment of base stations. Along with this growth, questions about the potential adverse effects on human health due to electromagnetic fields (EMFs) from base station antennas have also been raised. In this paper, we focus on the assessment of EMFs in automobiles during short (between cities) and long (between countries) trips on several European roads. Comprehensive measurement campaigns were carried out in several European countries: Austria, Bulgaria, Croatia, Hungary, Italy, Slovenia, and the Republic of Serbia. The results show that the median total electric field is 0.23–0.24 V/m in Bulgaria, Croatia, Hungary, Italy, and the Republic of Serbia. In Austria and Slovenia, the median is 0.28–0.31 V/m. Austria demonstrated the highest value for the total electric field, at 17.4 V/m.
28
Aricioglu, Burak, e Abdullah Ferikoglu. "Thermal Effects of 5G Frequency EM Waves on Ocular Tissue". Applied Computational Electromagnetics Society 36, n. 4 (10 maggio 2021): 386–97. http://dx.doi.org/10.47037/2020.aces.j.360404.
Abstract (sommario):
This research article aims to investigate the thermal effects on human eye due to exposure of EM (electromagnetic) field at 5G frequencies. A secondary purpose of the article is to show that SPICE, one of the most commonly used tools in circuit analysis, can be used to solve complex EM and bioheat transfer problems. Both electric field and temperature distributions in human eye are simulated with transmission line modelling (TLM) method. Also, finite element method (FEM) calculations are carried out for comparison. Temperature distributions are calculated for 30 minutes of EM radiation exposure. As a subject of the simulation, a human is chosen that the power density of incoming field at the human eye is assumed as the maximum of the ICNIRP general public exposure limits. A good consistency between TLM and FEM based simulations is found. A new transmission line model based on Debye parametric model is generated for simulation of EM field distribution in the tissues. With this generated transmission line, the results for the frequencies of interest can be obtained via single simulation. Also, a new transmission line model is developed for the temperature distribution simulation in which the effects of noncompressible fluid flow such as non-unidirectional blood flow in tissues and flow in aqueous humor are taken into consideration.
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Velghe, Maarten, Sergei Shikhantsov, Emmeric Tanghe, Luc Martens, Wout Joseph e Arno Thielens. "FIELD ENHANCEMENT AND SIZE OF RADIO-FREQUENCY HOTSPOTS INDUCED BY MAXIMUM RATIO FIELD COMBINING IN FIFTH GENERATION NETWORK". Radiation Protection Dosimetry 190, n. 4 (luglio 2020): 400–411. http://dx.doi.org/10.1093/rpd/ncaa118.
Abstract (sommario):
Abstract The goal of this paper is to experimentally assess the field enhancement and hotspot size of radio frequency electromagnetic fields created by the Maximum Ratio Combining (MRC) precoding scheme using lab measurements at 3.5, 5.5 and 11 GHz. MRC is an adaptive precoding scheme used by Massive Multiple Input Multiple Output systems, one of the enabling techniques of the fifth generation of telecommunications (5G). A virtual antenna array was used to compare MRC with two passive precoding schemes: the Random Phase Model (RPM) and the Centerline Beam Model (CBM). The field enhancement going from CBM to MRC was largest in obstructed line of sight (OLOS), ranging from 1.9 to 7.4 dB. The field enhancement going from RPM to MRC was about 9.5 dB across frequency bands in both line of sight (LOS) and OLOS. The hotspot size, quantified by the full width at half maximum (FWHM), ranged from 0.5 wavelengths to one wavelength.
30
Yang, Cheng, Ruinan Wu, Zhiliang Xiao e Wenfang Xu. "Design of Novel Ultra-wideband Slow-wave Microstrip Transmission Line". Journal of Physics: Conference Series 2480, n. 1 (1 aprile 2023): 012005. http://dx.doi.org/10.1088/1742-6596/2480/1/012005.
Abstract (sommario):
Abstract Microwave passive devices with high efficiency, small size, and light weight are one of the fundamental requirements for mobile communication coverage in the 5G frequency band. In this paper, the design of a novel ultra-wideband slow-wave microstrip transmission line is proposed and studied. The electromagnetic field simulation software HFSS is used to simulate the slow-wave microstrip transmission line, and the simulation results show that the ultra-wideband slow-wave structure has the advantage of wider bandwidth, smaller size, and lower cost, which meets the needs of 5G communication systems. Finally, the proposed slow-wave microstrip line is used in the U-shaped phase shifter, and the experimental results show that the novel slow-wave microstrip transmission line has a large application potential in the base station antenna system.
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Nadar Akila Mohan, P., e K. Indhumathi. "Sub-millimeter wave nanoantenna-a review". Journal of Physics: Conference Series 2484, n. 1 (1 maggio 2023): 012053. http://dx.doi.org/10.1088/1742-6596/2484/1/012053.
Abstract (sommario):
Abstract Electromagnetic waves that have a wavelength of less than one millimeter are referred to as sub millimeter waves. In sub millimeter wave-based devices and systems, antennas are critical components that are vital to their operation. Antennas are used in situations when a transition between a directed wave and a free-space wave is needed. Since, electromagnetic characteristics for receiving and transmission of the nano antenna are mutually invertible, the properties of nano antenna are analyzed in sub millimeter wave frequencies and this overcomes the limitations of conventional antenna design. They are very small in size, provide more efficiency, and do not cause health threat. This paper reviews the applications of nano antenna, which operates at sub-millimeter wave frequency, in the field of energy harvesting, space technology, IoT applications, 5G network, smart clothing, bio sensing, communication, etc? Also, the nano antenna fabricated by 3D printing technology is also reviewed. The world’s ever-increasing energy need necessitates the development of alternate energy sources. There is a lot of research and development going on right now to enhance photovoltaic systems so that they can be more efficient, but the constraint is that they can only collect energy from the visible area of the electromagnetic spectrum. As a result, a novel device known as a Nano antenna has been developed to convert heat energy taken from the infrared spectrum into electricity. In the not-too-distant future, it will have an impact on a wide range of fields, such as mobile communication (5G), radar detection, and higher order frequency applications. Space communication, broadband wireless communications, wireless optical communication, and mobile communication will also benefit from its implementation.
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Prado, Daniel R. "Near Field Models of Spatially-Fed Planar Arrays and Their Application to Multi-Frequency Direct Layout Optimization for mm-Wave 5G New Radio Indoor Network Coverage". Sensors 22, n. 22 (18 novembre 2022): 8925. http://dx.doi.org/10.3390/s22228925.
Abstract (sommario):
Two near field models for the analysis of spatially fed planar array antennas are presented, compared and applied to a multi-frequency wideband direct layout optimization for mm-Wave 5G new radio (NR) indoor network coverage. One model is based on the direct application of the radiation equations directly derived from the A and F vector potentials. The second model is based on the superposition of far field contributions of all array elements, which are modelled as rectangular apertures with constant field. Despite the different assumptions made to develop both models, the degree of agreement between them in the computation of the radiated near field is very high. The relative error between the models is equal or lower than 3.2% at a plane 13λ from the array, and it decreases as the near field is computed further away from the array. Then, the faster model is employed in a general direct layout optimization procedure to shape the electromagnetic near field for application in an indoor femtocell to provide coverage with constant power in a private office. Results show that a magnitude ripple better than 1.5 dB can be achieved in an enlarged coverage area covering the whole n257 band of the 5G NR, corresponding to a 10.7% relative bandwidth.
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Alam, M. Jubaer, e Saeed I. Latif. "Double-Split Rectangular Dual-Ring DNG Metamaterial for 5G Millimeter Wave Applications". Electronics 12, n. 1 (30 dicembre 2022): 174. http://dx.doi.org/10.3390/electronics12010174.
Abstract (sommario):
This article presents the design and analysis of a low profile double-negative (DNG) metamaterial unit structure for 5G mmWave (millimeter wave) applications. The structure, comprised of double-slotted rectangular ring patches, experiences the peak current value near the magnetic resonance, causing the metamaterial to resonate at 28 GHz where it exhibits negative effective permittivity and permeability. The 3.05 mm × 2.85 mm compact structure is designed over a substrate Rogers RT/Duroid 5880 to attain better effective medium ratio (EMR) in the 5G frequency range (27.1–29.2 GHz). A rigorous parametric study is conducted to obtain the proposed design. Full-wave electromagnetic simulation software tools CST and HFSS are used to generate the scattering parameters for the analysis. The Nicolson–Ross–Wier method is used to observe the negative effective permittivity and permeability. In addition, different output quantities, e.g., surface current and electric and magnetic field distribution, are investigated. The structure is further tested with 1 × 2, 2 × 2, and 4 × 4 arrays, where the results show adequate agreement to be considered for 5G mmWave applications.
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Atanasov, Nikolay Todorov, Gabriela Lachezarova Atanasova, Daniel Adrian Gârdan e Iuliana Petronela Gârdan. "Experimental Assessment of Electromagnetic Fields Inside a Vehicle for Different Wireless Communication Scenarios: A New Alternative Source of Energy". Energies 16, n. 15 (26 luglio 2023): 5622. http://dx.doi.org/10.3390/en16155622.
Abstract (sommario):
The search for new energy sources in the 21st century is a crucial topic with an essential economic and societal meaning. Today, energy from electromagnetic fields (EMFs) is considered a promising new energy source for ultra-low-power consumption devices, such as wearable devices and Internet of Things (IoT) sensors. The research goal of this study was to experimentally evaluate the electric field (E-field) inside a compact car for several realistic wireless communication scenarios and to explore the possibility of using these EMFs in energy-harvesting applications. For each scenario, we performed measurements of E-fields in an urban area, in two cases: when the car was in an open space without a direct line of sight to a base station, and when the car was in underground parking. The results show that the highest measured value of the electric field appeared during the voice calls via the GSM network. Moreover, the maximum measured values of the electric field during a UMTS, LTE and 5G voice call were five to six times lower than those in the GSM network.
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Aerts, Sam, Kenneth Deprez, Leen Verloock, Robert G. Olsen, Luc Martens, Phung Tran e Wout Joseph. "RF-EMF Exposure near 5G NR Small Cells". Sensors 23, n. 6 (15 marzo 2023): 3145. http://dx.doi.org/10.3390/s23063145.
Abstract (sommario):
Of particular interest within fifth generation (5G) cellular networks are the typical levels of radiofrequency (RF) electromagnetic fields (EMFs) emitted by ‘small cells’, low-power base stations, which are installed such that both workers and members of the general public can come in close proximity with them. In this study, RF-EMF measurements were performed near two 5G New Radio (NR) base stations, one with an Advanced Antenna System (AAS) capable of beamforming and the other a traditional microcell. At various positions near the base stations, with distances ranging between 0.5 m and 100 m, both the worst-case and time-averaged field levels under maximized downlink traffic load were assessed. Moreover, from these measurements, estimates were made of the typical exposures for various cases involving users and non-users. Comparison to the maximum permissible exposure limits issued by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) resulted in maximum exposure ratios of 0.15 (occupational, at 0.5 m) and 0.68 (general public, at 1.3 m). The exposure of non-users was potentially much lower, depending on the activity of other users serviced by the base station and its beamforming capabilities: 5 to 30 times lower in the case of an AAS base station compared to barely lower to 30 times lower for a traditional antenna.
36
Lebl, Aleksandar, e Đurađ Budimir. "Maximum electric field estimation in the vicinity of 5G base stations before their start-up". Vojnotehnicki glasnik 71, n. 2 (2023): 345–61. http://dx.doi.org/10.5937/vojtehg71-42426.
Abstract (sommario):
Introduction/purpose: This paper presents initial development of the procedure for electric field estimation in the vicinity of 5G base stations. Methods: The procedure allows determination of future radiation levels before traffic is established over applied antenna systems on the basis of measured values of electric field levels caused by the signal forming Synchronization Signal Block. It is possible to perform necessary calculations for a very accurate estimation even if some important parameters of the radiation characteristics (such as the frequency span between the frequency carriers on the radio interface) are not a priori known. In this way, communication with mobile system operators before measurement is significantly simplified because operators do not need to know system technical details. Results: The developed formula for electric field estimation is verified comparing the calculated values by its implementation to the practical results obtained by intensive measurements on a great number of 5G base stations in a highly developed country. The formula gives a pessimistic result, i.e. a higher electric field level than it is obtained by all such performed measurements. Conclusion: This estimation allows mobile system operators to predict whether the electromagnetic field around base stations could be dangerous for human health when systems come to full operation while considering national and international recommendations dealing with radiation levels.
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Matalatala, Michel, Margot Deruyck, Sergei Shikhantsov, Emmeric Tanghe, David Plets, Sotirios Goudos, Kostas E. Psannis, Luc Martens e Wout Joseph. "Multi-Objective Optimization of Massive MIMO 5G Wireless Networks towards Power Consumption, Uplink and Downlink Exposure". Applied Sciences 9, n. 22 (19 novembre 2019): 4974. http://dx.doi.org/10.3390/app9224974.
Abstract (sommario):
The rapid development of the number of wireless broadband devices requires that the induced uplink exposure be addressed during the design of the future wireless networks, in addition to the downlink exposure due to the transmission of the base stations. In this paper, the positions and power levels of massive MIMO-LTE (Multiple Input Multiple Output-Long Term Evolution) base stations are optimized towards low power consumption, low downlink and uplink electromagnetic exposure and maximal user coverage. A suburban area in Ghent, Belgium has been considered. The results show that the higher the number of BS antenna elements, the fewer number of BSs the massive MIMO network requires. This leads to a decrease of the downlink exposure (−12% for the electric field and −32% for the downlink dose) and an increase of the uplink exposure (+70% for the uplink dose), whereas both downlink and uplink exposure increase with the number of simultaneous served users (+174% for the electric field and +22% for the uplink SAR). The optimal massive MIMO network presenting the better trade-off between the power consumption, the total dose and the user coverage has been obtained with 37 64-antenna BSs. Moreover, the level of the downlink electromagnetic exposure (electric field) of the massive MIMO network is 5 times lower than the 4G reference scenario.
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Onishi, Teruo, Kaoru Esaki, Kazuhiro Tobita, Miwa Ikuyo, Masao Taki e Soichi Watanabe. "Large-Area Monitoring of Radiofrequency Electromagnetic Field Exposure Levels from Mobile Phone Base Stations and Broadcast Transmission Towers by Car-Mounted Measurements around Tokyo". Electronics 12, n. 8 (12 aprile 2023): 1835. http://dx.doi.org/10.3390/electronics12081835.
Abstract (sommario):
Car-mounted measurements of radiofrequency electromagnetic exposure levels were carried out in a large area around Tokyo. Prior to the electric field (E-field) measurements using a car, the effect of the car body was evaluated in an anechoic chamber. The measurements between May 2021 and February 2022 were carried out within a radius of 100 km centering on Nihonbashi, Tokyo, with a measurement distance of about 13,800 km. The measurement results were averaged in the reference area mesh (1 km2). It was found that the E-field strengths of FM/TV frequency bands are lower than that of mobile phone base stations. It was also found that the E-field strength of only the 5G frequency band is approximately 20–30 dB lower than that of all mobile phone systems. However, note that it is possible to depend on the data traffic of 5G. The E-field strength of all bands is higher in Tokyo than in other prefectures. Additionally, repeated measurements were carried out to investigate the reproducibility of the measured E-field. The standard deviation is less than 3 dB along the same route, and a similar tendency of E-field strength by the car to the time-averaged results of spot measurements in the past was confirmed. Finally, the relationship of E-field strength with population density was investigated. It was found that the E-field strength from mobile phone base stations has a positive relationship with population density.
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Foroughimehr, Negin, Zoltan Vilagosh, Ali Yavari e Andrew Wood. "The Impact of Base Cell Size Setup on the Finite Difference Time Domain Computational Simulation of Human Cornea Exposed to Millimeter Wave Radiation at Frequencies above 30 GHz". Sensors 22, n. 15 (8 agosto 2022): 5924. http://dx.doi.org/10.3390/s22155924.
Abstract (sommario):
Mobile communication has achieved enormous technology innovations over many generations of progression. New cellular technology, including 5G cellular systems, is being deployed and making use of higher frequencies, including the Millimetre Wave (MMW) range (30–300 GHz) of the electromagnetic spectrum. Numerical computational techniques such as the Finite Difference Time Domain (FDTD) method have been used extensively as an effective approach for assessing electromagnetic fields’ biological impacts. This study demonstrates the variation of the accuracy of the FDTD computational simulation system when different meshing sizes are used, by using the interaction of the critically sensitive human cornea with EM in the 30 to 100 GHz range. Different approaches of base cell size specifications were compared. The accuracy of the computation is determined by applying planar sensors showing the detail of electric field distribution as well as the absolute values of electric field collected by point sensors. It was found that manually defining the base cell sizes reduces the model size as well as the computation time. However, the accuracy of the computation decreases in an unpredictable way. The results indicated that using a cloud computing capacity plays a crucial role in minimizing the computation time.
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Hoque, Ahasanul, Mohammad Tariqul Islam e Ali F. Almutairi. "Low-Profile Slotted Metamaterial Antenna Based on Bi Slot Microstrip Patch for 5G Application". Sensors 20, n. 11 (11 giugno 2020): 3323. http://dx.doi.org/10.3390/s20113323.
Abstract (sommario):
A low-profile high-directivity, and double-negative (DNG) metamaterial-loaded antenna with a slotted patch is proposed for the 5G application. The radiated slotted arm as a V shape has been extended to provide a low-profile feature with a two-isometric view square patch structure, which accelerates the electromagnetic (EM) resonance. Besides, the tapered patch with two vertically split parabolic horns and the unit cell metamaterial expedite achieve more directive radiation. Two adjacent splits with meta units enhance the surface current to modify the actual electric current, which is induced by a substrate-isolated EM field. As a result, the slotted antenna shows a 7.14 dBi realized gain with 80% radiation efficiency, which is quite significant. The operation bandwidth is 4.27–4.40 GHz, and characteristic impedance approximately remains the same (50 Ω) to give a VSWR (voltage Standing wave ratio) of less than 2, which is ideal for the expected application field. The overall size of the antenna is 60 × 40 × 1.52 mm. Hence, it has potential for future 5G applications, like Internet of Things (IoT), healthcare systems, smart homes, etc.
41
Colombi, Davide, Paramananda Joshi, Bo Xu, Fatemeh Ghasemifard, Vignesh Narasaraju e Christer Törnevik. "Analysis of the Actual Power and EMF Exposure from Base Stations in a Commercial 5G Network". Applied Sciences 10, n. 15 (30 luglio 2020): 5280. http://dx.doi.org/10.3390/app10155280.
Abstract (sommario):
In this work, monitoring of the transmit power for several base stations operating in a live 5G network (Telstra, Australia) was conducted with the purpose of analyzing the radio frequency (RF) electromagnetic field (EMF) exposure levels. The base stations made use of state-of-the-art massive MIMO antennas utilizing beamforming in order to optimize the signal strength at the user’s device. In order to characterize the actual EMF exposure from 5G base stations, knowledge of the amount of power dynamically allocated to each beam is therefore of importance. Experimental data on the spatial distribution of the base stations’ transmit power were gathered directly from the network by extracting information on the radio and baseband operations. Out of more than 13 million samples collected over 24 h, the maximum time-averaged power per beam direction was found to be well-below the theoretical maximum and lower than what was predicted by the existing statistical models. The results show that assuming constant peak power transmission in a fixed beam direction leads to an unrealistic EMF exposure assessment. This work provides insights relevant for the standardization of EMF compliance assessment methodologies applicable for 5G base stations.
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Schirru, Luca, Filippo Ledda, Matteo Bruno Lodi, Alessandro Fanti, Katiuscia Mannaro, Marco Ortu e Giuseppe Mazzarella. "Electromagnetic Field Levels in Built-up Areas with an Irregular Grid of Buildings: Modeling and Integrated Software". Electronics 9, n. 5 (6 maggio 2020): 765. http://dx.doi.org/10.3390/electronics9050765.
Abstract (sommario):
The knowledge of the electromagnetic field levels generated by radio base stations present in an urban environment is a relevant aspect for propagations and coverage issues, as well as for the compliance to national regulations. Despite the growing interest in the novel fifth generation (5G) technology, several aspects related to the investigation of the urban propagation of the Global System of Mobile Communication (GSM), third generation (3G), and fourth generation (4G) mobile systems in peculiar non-rural environments may be improved. To account for irregular geometries and to deal with the propagation in hilly towns, in this work we present an enhanced version of the COST231-Walfisch–Ikegami model, whose parameters have been modified to evaluate the path loss at distances greater than 20 meters from the radio base station. This work addressed the problem of providing an effective, reliable, and quantitative model for the estimation of electromagnetic field levels in built-up areas. In addition, we also developed and tested a pre-industrial software prototype whose aim is to make the estimated electromagnetic field levels available to the key players in the telecom industry, the local authorities, and the general population. We validated the proposed model with a measurement campaign in the small urban and irregular built-up areas of Dorgali (Nuoro), Cala Gonone (Nuoro), and Lunamatrona (Cagliari) in Sardinia (Italy).
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Amanatiadis, Stamatis, Vasileios Salonikios, Nikolaos Kantartzis e Traianos Yioultsis. "Performance analysis of a novel metamaterial-inspired substrate-integrated cavity for 5G applications". EPJ Applied Metamaterials 11 (2024): 6. http://dx.doi.org/10.1051/epjam/2024009.
Abstract (sommario):
The functionality of a fully planar metamaterial-inspired substrate-integrated cavity is thoroughly investigated in the present work. The electromagnetic field confinement of the proposed device is realized with the utilization of broadside-coupled complementary split ring resonators that operate as a virtual electric wall. The numerical results from the eigenvalue analysis verify the presence of the fundamental resonances with a noteworthy quality factor. Subsequently, full-wave simulations are conducted to validate the resonance functionality of the proposed device, with excitation achieved using the metallic core of a coaxial cable. Numerical results highlighted, also, the radiation capabilities exploiting the inherent openings in the device due to the complementary resonators.
44
Feng, Qiang, Yifeng Lin, Yushan Zheng e Long Li. "Vortex Beam Optimization Design of Concentric Uniform Circular Array Antenna with Improved Array Factor". Applied Computational Electromagnetics Society 36, n. 7 (19 agosto 2021): 830–37. http://dx.doi.org/10.47037/2021.aces.j.360702.
Abstract (sommario):
In this paper, an improved array factor of the concentric uniform circular array (CUCA) antenna is proposed for the orbital angular momentum (OAM) vortex beam optimization design. From the perspective of the radiation pattern’s power conservation principle, a correction factor is introduced to the conventional array factor of CUCA. Then, based on the improved array factor, by adjusting the rings’ radii parameters of the CUCA, we optimize the vortex beam’s sidelobe level through the generic algorithm (GA). Two different CUCA antenna model are calculated as examples to further illustrate the effectiveness of the improved array factor. Subsequently, an electromagnetic simulation model of two rings CUCA antenna is built at C band for generating low sidelobe vortex beam carrying OAM mode. The electromagnetic simulation model of the designed CUCA antenna is also fabricated and measured. The corresponding antenna far-field vortex beam radiation pattern and near-field vortex wave electric field distributions are measured. The simulation results and the measurement results are in good agreement. The proposed designs of antenna and OAM vortex beam regulation are expected to be used for 5G and 6G communications applications
45
Chao Kang, Chia, Fatin Ayuni e Chia Yang Kang. "Development of High Gain Circularly Polarized Antenna Array for RF Renewable Energy". International Journal of Engineering & Technology 7, n. 2.29 (22 maggio 2018): 1033. http://dx.doi.org/10.14419/ijet.v7i2.29.14304.
Abstract (sommario):
RF energy has become very attractive in the engineering and scientist field for green substainbility. A novel high gain circularly polarize antenna array for RF renewable energy is presented in this paper. The antenna structure was investigated using full wave electromagnetic field analysis. Finally, the entire structure of the antenna array was fabricated and measured. A comparison between simulated and measured results has been observed. The results show that high gain 5.0dBi at 956MHz had been achieved for circularly polarize antenna array and the works concludes that the investigation of high gain antenna system was successful and it can use as an alternatif sources for renewable green energy. The antenna structure that presented is also an important part of the IoT and 5G development.
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Zhou, Wen-Ying, Xi-Yu Zhang e Mai Lu. "Electromagnetic exposure analysis of the subway passenger under the civil communication system radiation". PLOS ONE 19, n. 3 (11 marzo 2024): e0300049. http://dx.doi.org/10.1371/journal.pone.0300049.
Abstract (sommario):
In order to assess the electromagnetic exposure safety of passengers under the civil communication system of the subway, the radio-frequency (RF) electromagnetic environment of subway carriage is established by using COMSOL Multiphysics software, it includes a 1-1/4 " leaky coaxial cable (LCX1) and a 1-5/8" leaky coaxial cable (LCX2), which are designed to be the exposure sources, and twelve passengers at different position. The electromagnetic environment model has been verified through field measurement. The exposure dose distribution of twelve passengers is compared and analyzed, when LCX1 and LCX2 works respectively. The simulated results show that, to compare with LCX2, the electromagnetic dose absorbed by the passengers is reduced by 9.19% and 22.50% at 2100 MHz and 2600 MHz respectively. The specific absorption rate (SAR) of passengers obtains the maximum value of 1.91×10−4 W/Kg and the temperature rise to 0.214 K when the LCX1 works at 3400 MHz. By comparing with the public exposure limitation of the International Commission of Non-Ionizing Radiation Protection (ICNIRP), it demonstrates the electromagnetic exposure safety of the passengers under the civil communication system. More importantly, the proposed LCX1 not only could add the 5G signal cover but also lower the SAR absorbed by the passengers, which indicates that the public electromagnetic exposure dose could be reduced by adjusting the radiation performances of exposure source, which provide a new way for electromagnetic protecting.
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Matthew, Ugochukwu O., e Jazuli S. Kazaure. "Chemical polarization effects of electromagnetic field radiation from the novel 5G network deployment at ultra high frequency". Health and Technology 11, n. 2 (27 gennaio 2021): 305–17. http://dx.doi.org/10.1007/s12553-020-00501-x.
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Wersényi, György. "Health issues using 5G frequencies from an engineering perspective: Current review". Open Engineering 12, n. 1 (1 gennaio 2022): 1060–77. http://dx.doi.org/10.1515/eng-2022-0387.
Abstract (sommario):
Abstract The possible adverse health effects of electromagnetic field (EMF) exposure have been in research focus since radio waves were introduced to telecommunication. Broadcast radio systems, satellites, and mobile communication devices use different bands of the radio spectrum, antennas, modulations, and radiated power. The proliferation of cellular networks and mobile phones as user devices have brought transmitting and receiving antennas in the close proximity of the human body and the head. Hundreds of experiments have been conducted to prove and disprove adverse health effects of exposure. Literature reviews of experimental results have also followed the current developments in technology; however, an exhaustive analysis performed on the methodologies has revealed many flaws and problems. This article focuses on the latest results on frequency bands mostly used for 5G below and above 6 GHz in the mmWave band. Current results do not indicate significant health effects and responses below the current safety limits. Nevertheless, further research directions can be identified, especially for mmWave radiation.
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Poljak, Dragan, e Josipa Saric. "Assessment of local temperature elevation at the surface of tissue exposed to radiation of milimeter waves using simplified analytical approach". Journal of Physics: Conference Series 2766, n. 1 (1 maggio 2024): 012189. http://dx.doi.org/10.1088/1742-6596/2766/1/012189.
Abstract (sommario):
Abstract Dominant effect of human exposure to electromagnetic fields in GHz frequency range corresponding to operation of 5G mobile communications systems is tissue heating i.e. local temperature elevation at the body surface, i.e. skin, ear and eyes. For the frequencies below transition frequency of 6GHz specific absorption rate (SAR) is used to quantify the volume heating. On the other hand, the surface heating above 6GHz is quantified via absorbed power density (Sab ). Once these quantities are determined by means of internal field dosimetry procedures it is possible to determine the local surface temperature increase by solving the bio-heat transfer equation. The present paper deals with the calculation of tissue surface heating due to exposure to millimeter waves. Internal dosimetry is based on the planar tissue model exposed to dipole antenna radiation. Electromagnetic model is based on the analytical solution of Pocklington integro-differential equation while the assessment of tissue surface heating in planar tissue model has been carried by analytically solving a simplified variant of the bio-heat transfer equation. Some illustrative results for power density and temperature elevations will be presented for different antenna parameters.
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Schilling, Lisa-Marie, Christian Bornkessel e Matthias A. Hein. "Human RF Electromagnetic Exposure to V2X-Communication". Advances in Radio Science 19 (15 settembre 2022): 233–39. http://dx.doi.org/10.5194/ars-19-233-2022.
Abstract (sommario):
Abstract. In the era of automated and connected driving, more and more cars will be equipped with wireless transmission technologies such as mobile communications 4G (LTE) and 5G, WiFi, Bluetooth, and V2X. For the technical implementation of V2X-communications, different standards like cellular-V2X from the cooperation 3rd Generation Partnership Project and ITS-G5, based on the WiFi standard 802.11p from the Institute of Electrical and Electronics Engineers, are under consideration. The electromagnetic environment of cars and the corresponding exposure of the general public to wireless emission will be significantly influenced by new radio technologies. Under all circumstances, it must be ensured that the exposure of the electromagnetic fields inside a car does not cause any harmful effects on humans. In order to quantitatively assess the resulting exposure, the generated exposure must be correctly recorded and evaluated according to their specific time-frequency spectra. This paper describes a new measurement procedure suitable for the V2X-standard ITS-G5 together with various exposure measurements performed in different cars with WiFi, Bluetooth and ITS-G5. In comparison of all wireless standards studied here, the V2X-service generated the highest electric field strengths inside a car, when a transmitting di-patch antenna was mounted on the windscreen inside the driver's cabin. The maximum fraction of the corresponding ICNIRP reference level amounted to 15.1 %. We conclude that the total exposure of wireless on-board automotive devices will be dominated by ITS-G5, if the transmitting antenna is located inside the passenger cabin. As V2X-communications will increasingly penetrate road traffic, the resulting exposure should be carefully monitored, in order not to exceed the corresponding reference levels for general public.