Electromagnetic Field Levels Research Articles

Electromagnetic Field Levels in Built-up Areas with an Irregular Grid of Buildings: Modeling and Integrated Software

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).

Spectral density constraints on wireless communication

Environmental exposure to man-made electromagnetic field (EMF) has been rising as modern technologies have grown and changes in social behavior have generated more synthetic sources. For safety of human health, EMF levels need to be regulated. The level of EMF should be well below levels where there might be harm, hence we do not expect to see any health effects at these levels. Current regulations fail to place a strict limit on EMF in situations where multiple nearby devices transmit simultaneously. The way these regulations are expressed needs great care because it will have an effect on the design of wireless communication systems. In this paper, it is argued that transmitted power constraints on wireless communication devices should be expressed in a different way, namely that devices should limit the EMF spectral density that they generate to the difference between the maximum allowed, by the standard, and the amount currently present, as measured by the device, in the spectral region where it is active. Note that the limit on EMF should be expressed in terms of its EMF spectral density rather than as a total EMF over each of a series of separate bands. If all devices limit their own EMF spectral density, in the spectral region where they are active, in such a way that total EMF spectral density is below the regulated limit in that region, then it is certain that the aggregate EMF spectral density will be below the regulated limit at all frequencies.

Analysis and development of an electromagnetic exposure map based in spatial interpolation

The increasing demand for electricity has led humans to a growing exposure to artificial sources of electromagnetic emission, making it essential to determine the intensity of electromagnetic fields (EMFs), which is subject to the population of a given area. This Letter proposes an analysis of EMF exposure levels and spatial distribution over the region of the input and power circuits of a 230 kV/60 Hz air-insulated substation. For this, measurement protocols were determined based on current standards and from spatial interpolation methods, a contour map was developed, allowing a complete evaluation of the behaviour and levels of EMF throughout the region. The results obtained indicate that exposure levels in this region are below those recommended by regulatory agencies.

Electromagnetic hypersensitivity (EHS, microwave syndrome) – Review of mechanisms

Electromagnetic hypersensitivity (EHS), known in the past as “Microwave syndrome”, is a clinical syndrome characterized by the presence of a wide spectrum of non-specific multiple organ symptoms, typically including central nervous system symptoms, that occur following the patient's acute or chronic exposure to electromagnetic fields in the environment or in occupational settings. Numerous studies have shown biological effects at the cellular level of electromagnetic fields (EMF) at magnetic (ELF) and radio-frequency (RF) frequencies in extremely low intensities. Many of the mechanisms described for Multiple Chemical Sensitivity (MCS) apply with modification to EHS. Repeated exposures result in sensitization and consequent enhancement of response. Many hypersensitive patients appear to have impaired detoxification systems that become overloaded by excessive oxidative stress. EMF can induce changes in calcium signaling cascades, significant activation of free radical processes and overproduction of reactive oxygen species (ROS) in living cells as well as altered neurological and cognitive functions and disruption of the blood-brain barrier. Magnetite crystals absorbed from combustion air pollution could have an important role in brain effects of EMF. Autonomic nervous system effects of EMF could also be expressed as symptoms in the cardiovascular system. Other common effects of EMF include effects on skin, microvasculature, immune and hematologic systems. It is concluded that the mechanisms underlying the symptoms of EHS are biologically plausible and that many organic physiologic responses occur following EMF exposure. Patients can have neurologic, neuro-hormonal and neuro-psychiatric symptoms following exposure to EMF as a consequence of neural damage and over-sensitized neural responses. More relevant diagnostic tests for EHS should be developed. Exposure limits should be lowered to safeguard against biologic effects of EMF. Spread of local and global wireless networks should be decreased, and safer wired networks should be used instead of wireless, to protect susceptible members of the public. Public places should be made accessible for electrohypersensitive individuals.

Design of a Cylindrical Winding Structure for Wireless Power Transfer Used in Rotatory Applications

A cylindrical joint structure for wireless power transfer (WPT) systems is proposed. The transmitter (Tx) and receiver (Rx) coils were wound on hemicylindrical and cylindrical structures, respectively. The Rx coil rotates freely around the axial direction of the Tx coil. Different methods of winding the Tx and Rx coils are given and discussed. Electromagnetic fields (EMFs) around the WPT windings should be lower than the limits set by WPT standards. Therefore, the WPT windings were designed to reduce EMF level and maintain constant power-transfer efficiency (PTE). The design procedures of the windings are discussed in detail. EMF analysis was done under different rotation angles (α). The selected design reduced the variation of the mutual inductance (M). As a result, it maintained a constant PTE while rotating the Rx coil between 0° and 85°. Moreover, leakage magnetic fields (LMFs) near the WPT coils of the chosen design were reduced by 63.6% compared with other winding methods that have the same efficiency. Finally, a prototype was built to validate the proposed idea. Experiment results were in good agreement with the simulation results. The WPT system maintained constant efficiency in spite of the rotation of Rx coil, where efficiency dropped by only 2.15% when the Rx coil rotated between 0° and 85°.

Microdosimetry Using Rhodamine B Within Macro- and Microsystems for Radiofrequency Signals Exposures of Biological Samples

Exposing living cells to a certain level of electromagnetic field (EMF) might induce some biological effects including temperature elevation. In this article, we studied two exposure systems at the macro and microscopic levels, allowing the study of the EMF effect on the biological samples exposed to 1.8-GHz signals. The macrosystem was an open transverse electromagnetic (TEM) cell that served as a dosimetry reference for defining limitations and optimal conditions for the temperature calibration using Rhodamine B (RhodB). The microfluidic microsystem was based on the coplanar waveguide (CPW) electrodes. Temperature measurements are carried out with a fluorooptic probe to extract specific absorption rate (SAR) values that are compared with numerical dosimetry, based on an FDTD method. After calibration, the fluorescence fits well with the temperature variation measured by the probe. To investigate dosimetry at a microscopic level, the fluorescence of the temperature-dependent dye RhodB was measured by fluorescence microscopy within the microfluidic channel or the biological cells. Results evidenced that the technique is applicable for RhodB concentrations higher than 1 μm with a value of 50 μm recommended for reliable experiments. For steady detection and SAR assessments, temperature variations of a few tenths of degrees were required.

ЗАГАЛЬНІ ЗАСАДИ ПРОЕКТУВАННЯ ЕЛЕКТРОМАГНІТНИХ ЕКРАНІВ ТА ЕКРАНУЮЧИХ КОНСТРУКЦІЙ

В умовах складної електромагнітної обстановки, що формується за рахунок впливу зовнішніх та внутрішніх джерел, а також внаслідок широкого застосування бездротових систем передачі інформації, завдання, пов’язані із застосуванням екрануючих конструкцій значно ускладнюються. Зокрема, необхідність забезпечення стабільної роботи мобільного зв’язку накладає певні обмеження на коефіцієнти екранування захисних матеріалів. Це потребує визначення загальних підходів до запровадження екранування на принципах розумної достатності, враховуючи як захист людей від електромагнітних впливів, так і виробничі потреби. Встановлено, що необхідним є розроблення схеми проектування електромагнітних екранів з урахуванням складності електромагнітної обстановки. Мета роботи – розроблення загальних засад проектування екрануючих матеріалів та конструкцій з урахуванням гранично допустимих рівнів магнітних та електромагнітних полів різного походження. Обґрунтовано, що для проектування магнітних та електромагнітних екранів доцільно використати експериментальні дані щодо залежності коефіцієнтів екранування від товщини захисного матеріалу, вмісту екрануючої металевої та металовмісної субстанції у полімерній матриці тощо. Визначено коефіцієнти екранування магнітного поля промислової частоти, електромагнітного поля частотою 1,8 ГГц та геомагнітного поля композиційними металополімерними матеріалами різної товщини та характеристик. Встановлено, що оптимізація параметрів матеріалів щодо впливів полів цих трьох походжень неможлива. Наведено схему, яка може бути використана за наявності електромагнітних полів різного походження та широкого частотного спектра. Але передумовою таких робіт є проведення моніторингу електромагнітної обстановки у виробничих приміщеннях з визначенням амплітудно-частотних характеристик електромагнітних полів різного походження. Здійснення проектних та впроваджувальних робіт за розробленою схемою є найбільш доцільним підходом щодо проектування захисних матеріалів та екрануючих конструкцій. Такий підхід мінімізує витрати часу та коштів на роботи з електромагнітної безпеки

NATIONAL OBSERVATORY OF ELECTROMAGNETIC FIELDS: NATIONAL TELEMETRIC NETWORK FOR THE MEASUREMENT OF HIGH-FREQUENCY ELECTROMAGNETIC FIELDS IN GREECE.

At the end of 2015, the operation of the National Observatory of Electromagnetic Fields (established in 2012) has started. The National Observatory of Electromagnetic Fields is a network of 500 fixed (480 broadband and 20 frequency selective) and 13 mobile (vehicle mounted frequency selective) measurement stations throughout Greece that continuously monitor the electromagnetic field levels from all kinds of antenna stations in the frequency range 100kHz-7GHz. The results of this national monitoring network, which is operated and controlled by the Greek Atomic Energy Commission (EEAE), are presented through an interactive web portal (https://paratiritirioemf.eeae.gr), in which data are constantly updated with the latest station measurements. This paper presents the operational aspects and the measurement results of the first 3 years of operation (2016-2018). The measurement results revealed that all values were well below the reference levels for general public exposure, as defined by the Greek legislation.

Monitoring of Data Transmission and Changes in Values of Electromagnetic Field in Living Environment

A crucial aspect concerning the intelligent transport systems is data transmission between vehicle and central control and information systems. Transportation needs a reliable system of data transfer based on GSM or WiFi networks. However, these networks employ a wide range of different frequencies which can be harmful to the health of drivers. The detrimental effect of electromagnetic radiation can negatively affect the process of transportation. This study determines the intensity of electric field levels (E) of the radiofrequency electromagnetic field (RF EMF) during the data transmission through the 3G, 4G and local WiFi networks, comparing them with the limit values. Conclusions: Our results showed a significantly higher level of the E-field intensity during 4G transmission in all places. The limit values were not exceeded. The lowest E-field values were found in local WiFi network.

Планування та впровадження заходів з електромагнітної безпеки у промислових будівлях та спорудах

Objective. Identification of factors of non-productive origin that affect the electromagnetic situation in industrial buildings and the implementation of a sequence of measures to normalize it. Methods. Experimental study of the source of extraneous electromagnetic fields in buildings and structures that can adversely affect workers and sensitive devices in production. To do this, the means of finding such fields were identified and used. The state and description of electric power networks as well as the distribution of the intensity of high-frequency electromagnetic fields are generalized. Electromagnetic safety measures in the production of various purposes are analyzed and presented. Results. Industrial five-storey buildings were inspected for currents in metal structures. The results show that they have significant levels of electric currents in metal structures depending on the riser of the building. It is established that the precondition for the application of safety measures is the analysis of the state of electric power networks, the distribution of the intensity of high-frequency electromagnetic fields, etc. The levels of electromagnetic fields in partially shielded rooms have been experimentally established. Typical dependences of radiation intensity of mobile phones on the signal level from base stations are obtained. The conditions of normalization of the electromagnetic situation in individual rooms and the building as a whole are substantiated. Electromagnetic safety measures have been introduced. Scientific novelty. To minimize the impact of electrical networks on the electromagnetic environment in the building, it is advisable to upgrade it according to the scheme TN-S, or TN-C-S, which reduces the levels of uncompensated electric currents in the network and the corresponding magnetic fields. Practical significance. It is established that: a) it is obligatory to determine the presence of leakage electric currents on grounded bearing structures and engineering networks that generate magnetic fields of hygienically significant voltages; b) reducing the levels of these jets due to technical solutions further reduces the intensity of electro-like processes in metal structures; c) to reduce the levels of high-frequency electromagnetic fields in production facilities, which are formed due to the reflection and re-reflection of electromagnetic waves, it is advisable to use composite shielding materials with controlled absorption and reflection coefficients. This approach will systematize the overall electromagnetic background in the premises and the building as a whole.

Проблемы электромагнитной безопасности в урбанизированном пространстве

The term «global electromagnetic pollution of environment» was officially introduced in 1995 by the World Health Organization (WHO), which included this problem in the list of top-priority ones for the mankind. Living organisms, including humans, have become adapted to certain levels of electromagnetic fields (EMFs); however, a significant and very rapid (in the historical scale) growth in the EMF levels has a challenging influence on the adaptive and compensation capabilities of the organism. A long-term effect of this factor may lead to exhaustion of these capabilities, which will entail irreversible consequences at the system level. The article considers the main sources of electromagnetic pollution in urbanized environment, methods for calculating the field intensities produced by electromagnetic field sources, problems associated with electromagnetic pollution and with assurance of the electromagnetic safety of equipment and people in urbanized environment.

A case-study on the effect of averaging duration on RF dosimetry of general public environments

Electromagnetic waves can cause undesirable effects on the human body. These hazards have forced the related certification bodies such as ICNIRP and IEEE to propose standard limitations on the electromagnetic field levels. However, the current recommended procedures demand to verify the safety compliance of each measurement point based on a lengthy and impractical 6 minute averaging, in addition to spatial averaging, which complicates the procedure of RF dosimetry. Our statistical analysis on the performed experimental indoor and outdoor measurements show that lower time interval of measurements, such as 30 seconds and 60 seconds, predicts the same results in common electromagnetic environments affected by wireless networks and broadcasting signals. The overall observed difference between 30 seconds and 6 minute averaging time length from our reference value is less than 50% respectively in 13.5% and 10% of times, illustrating that there is not a significant difference between 30 seconds and 6 minute averaging. This makes the RF dosimetry procedure much faster and less expensive, while reliability is nearly the same.

A Theoretical and Experimental Investigation on the Measurement of the Electromagnetic Field Level Radiated by 5G Base Stations

This paper presents some theoretical considerations and experimental results regarding the problem of maximum power extrapolation for the assessment of the exposure to electromagnetic fields radiated by 5G base stations. In particular the results of an extensive experimental campaign using an extrapolation procedure recently proposed for 5G signal is discussed and experimentally checked on a SU-MIMO signal. The results confirm the effectiveness of the extrapolation technique. Starting from an analysis (that represents a further novel contribution of this paper) on the impact of Spatial Division Multiple Access techniques used in 5G on the measurement of EMF level, some indications of possible extension of the technique to the highly complex MU-MIMO case are also given.

Yüksek gerilim hattına yakın evlerde elektromanyetik alan düzeyleri ve semptom varlığı

Amaç: Bu çalışmanın amacı yüksek gerilim hattı yakınında bulunan evlerde elektromanyetik alan düzeylerinin ve bu evlerde yaşayanlarda bazı semptomların varlığının belirlenmesidir. Gereç ve Yöntem: Bu amaçla bu tanımlayıcı çalışmada Ankara’da, yakınında yüksek gerilim hattı bulunan 74 evde ve evin bulunduğu binanın çevresinde elektromanyetik alan ölçümü yapılmış ve bu evlerde yaşayan 18 yaş üstü 141 kişiye sağlık durumlarının ve semptomların değerlendirildiği bir anket uygulanmıştır. Bulgular: Evlerde elektromanyetik alan ortalaması 2,18 ±1,25 mG olarak saptanmıştır, %41,9’u 1-3. kattadır. Evlerin balkonları elektromanyetik alan ortalamalarının en fazla olduğu alanlar olmuştur. Katılımcıların %50,4’ü erkek, %%66,4’ü 50 yaş üstündeydi. Evlerdeki elektromanyetik alan düzeyi ile yüksek gerilim hattına uzaklık arasında istatistiksel olarak anlamlı ve negatif bir korelasyon belirlenmiştir. Sorgulanan semptom sıklığı ve toplam semptom sayısı ile evde ölçülen elektromanyetik alan düzeyleri arsında anlamlı farklılık bulunamadı. Sonuç: Elektromanyetik alanlar sağlıkla ilgili çeşitli endişelere neden olmaktadır. Bu alanda sağlık etkileri ile ilgili çalışmalar artırılmalıdır. Bu tanımlayıcı çalışmanın sonuçları farklı değerlendirme yaklaşımlarının ortaya konulmasının yararlı olacağını göstermektedir.

CT2A Cell Viability Modulated by Electromagnetic Fields at Extremely Low Frequency under No Thermal Effects.

The effects produced by electromagnetic fields (EMFs) on human beings at extremely low frequencies (ELFs) have being investigated in the past years, across in vitro studies, using different cell lines. Nevertheless, the effects produced on cells are not clarified, and the cellular mechanisms and cell-signaling processes involved are still unknown. This situation has resulted in a division among the scientific community about the adequacy of the recommended level of exposure. In this sense, we consider that it is necessary to develop long-term exposure studies and check if the recommended levels of EMFs are under thermal effects. Hence, we exposed CT2A cells to different EMFs at different ELFs at short and long times. Our results showed frequency dependence in CT2A exposed during 24 h to a small EMF of 30 μT equal to those originated by the Earth and frequency dependence after the exposure during seven days to an EMF of 100 µT at different ELFs. Particularly, our results showed a remarkable cell viability decrease of CT2A cells exposed to EMFs of 30 Hz. Nevertheless, after analyzing the thermal effects in terms of HSP90 expression, we did not find thermal damages related to the differences in cell viability, so other crucial cellular mechanism should be involved.

Environmental radiofrequency electromagnetic field levels in a department of pediatrics

Preterm neonates constitute a vulnerable population that is highly sensitive to its environment. Given the increased use of wireless communication devices (mobile and digital enhanced cordless telecommunications, WiFi networks, etc.), neonates hospitalized in a department of pediatrics are potentially exposed to radiofrequency electromagnetic fields (RF-EMF). Strikingly, data on RF-EMF levels in pediatric units have not previously been published.The objective of the present study was thus to quantify the RF-EMF levels in a 34-bed tertiary department of pediatrics with a neonatal critical care unit (NCCU) and a neonatal intensive care unit (NICU). To this end, we used triaxle antenna dosimeters to map the RF-EMF levels in the environment and to measure spot emissions from medical devices. In a first set of experiments, RF-EMF levels at 144 points in the staff area and in the children's rooms in the NCCU and NICU were evaluated over a 24-h period. In a second set of measurements performed in a Faraday chamber, we measured the RF-EMF levels emitted by the medical devices to which neonates are potentially exposed in the department of pediatrics.The RF-EMF levels were significantly higher in the NCCU than in the NICU (p < 0.05). Although the two units did not differ significantly with regard to the average maximum values, the single greatest value recorded in the NCCU (6 V/m GSM + UMTS 900 (UL) frequency band, in the staff area) was more than twice that recorded in the NICU (3.70 V/m in the UMTS 2100 (UL) frequency band, in the children's rooms). The NCCU and NICU did not differ significantly with regard to the time during which the RF-EMF level at each measurement point was more than two standard deviations above its mean. The RF-EMF level was significantly higher during the day than during the night (p < 0.001). The various medical devices used in the NICU did not emit detectable amounts of RF.Overall, RF-EMF levels in the NCCU and NICU were very low. It is probable that the RF-EMFs measured here were primarily generated by the parents' and staff members' activities, rather than by medical devices. However, a combination of low-level, chronic exposure with transient, elevated peak values in a vulnerable population of preterm neonates may be of particular concern. In a department of pediatrics, decreasing preterm neonates’ exposure to RF-EMFs should primarily involve a limitation on the use of wireless communication devices by staff members and parents.

Shielding properties study of the fabrics obtained by magnetron spraying

The article deals with the method of the modification of polyester fabrics used to create a coating that protects against electromagnetic radiation. As a method of modifying the technical properties of the polyester material, treatment in a magnetron spraying unit is proposed. Aluminum and titanium are used as sprayed materials. The use of the studied samples of metallized tissue leads to the significant decrease in the levels of electromagnetic fields.

ГИГИЕНИЧЕСКАЯ ОЦЕНКА УРОВНЕЙ ЭЛЕКТРОМАГНИТНОГО ПОЛЯ ЭЛЕКТРОННОЙ ИНФОРМАЦИОННО-ОБРАЗОВАТЕЛЬНОЙ СРЕДЫ ШКОЛ

Results of the study on hygienic assessment of the electromagnetic field levels of the electronic information-educational schools’ environment showed that the intensity values of the electromagnetic field were within the limits of the permissible levels in conference rooms, in recreation, in canteens, in classrooms and in workplaces of computer and distance-learning rooms. The packages of system units, small servers, microwave ovens, monitors, televisions, laptops, sockets and extension cords were the main sources of electromagnetic radiation in modern comprehensive schools. The values of electromagnetic radiation of ultrahigh frequencies in the general education establishments were within the limits of the maximum permissible levels. We have been developed recommendations for the hygienic safety of the information-communication technology use and the equipment and furniture placement in computer classes of comprehensive schools.

Role of P2X7 receptor in the osteogenic differentiation of bone marrow stromal cells induced by electromagnetic fields

Objective The aim of this study was to elucidate the role of P2X7 receptors in the osteogenic differentiation of bone marrow stromal cells (BMSCs) induced by electromagnetic fields (EMF), and the underlying mechanism. Methods BMSCs of 4-week-old male SD rat were isolated and cultured in vitro. The cells at passage 3 were used in this study. To select the most effective frequency EMF, mRNA and protein levels of P2X7 receptoe in BMSCs, which were induced by 1 mT, 7.5-75.0 Hz positive metaphysical EMF for 1 week, were investigated by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) and Western blotting. BMSCs cultured in osteogenic medium with or without A740003 (a specific P2X7 antagonist, 5 μmol/L) were stimulated by selected frequency EMF for 1 week, and then expression of runt related transcription factor-2 (Runx2), alkaline phosphatase (ALP), osteopontin (OPN) and activation of protein kinase B (Akt)/glycogen synthase kinase 3β (GSK3β)/β-catenin in BMSCs were investigated by Western blotting or RT-qPCR.Measurement data were expressed as (Mean ± SD) and ANOVA analysis of variance was used. Results 1 mT, 15 Hz EMF exhibited the optimal effect on expression of P2X7 receptor, and the relative expression of P2X7 mRNA and protein was 2.0 times and 1.9 times as much as that in control group, respectively. The relative expression of RUNX2, ALP and OPN mRNA in 1 mT, 15 Hz EMF group were 2.1, 5.3 and 3.7 times of that in control group, and the relative expression of RUNX2, ALP and OPN protein was 1.3, 1.6 and 1.5 times of that in control group, respectively. When BMSCs induced by A740003 medium were stimulated by 1 mT, 15 Hz EMF, the relative expression of RUNX2, ALP and OPN mRNA decreased by 36%, 42% and 41% than that in control group, and the relative expression of RUNX2, ALP and OPN protein decreased by 28%, 30% and 26% than that in control group, respectively. Use of A740003 or phosphoinositol 3 kinase (PI3K)/Akt pathway blocker LY294002 (5 μmol/L) alone decreased the levels of phosphorylated Akt and GSK3β induced by EMF, and also decreased the expression of intracellular β-catenin. Conclusion EMF increase the expression of P2X7 of rat BMSCs, which activates Akt/GSK3β/β-catenin axis and finally promotes the osteogenesis. Key words: Electromagnetic fields; Purinergic receptor P2X7; Bone mesenchymal stem cells; Osteogenic differentiation

Comparative Analysis and Design of the Shielding Techniques in WPT Systems for Charging EVs

Wireless power transfer (WPT) systems for charging Electric Vehicles (EVs) have gained extensive attention due to their many advantages. However, human exposure to electromagnetic fields (EMFs) has become a serious concern in high-power cases. In this paper, shielding techniques, including magnetic, metallic, and resonant reactive current shields, are investigated. Finite element method software is used to evaluate and compare the shielding effectiveness, charger weight, and system performance. The results show that the resonant reactive current shielding has a low EMF level with reasonable system efficiency and acceptable charger weight. In addition, 5 kW with 15 cm air gap WPT chargers were built to validate the simulation results.