Evaluation of Specific Absorption Rate due to Medical Implant in Near-Field Exposure

2013 ◽  
Vol 64 (3) ◽  
Author(s):  
Nazirah Othman ◽  
Noor Asmawati Samsuri ◽  
Norfatin Akma Ellias
Keyword(s):  
Intramedullary Nail ◽  
Specific Absorption Rate ◽  
Near Field ◽  
Dipole Antenna ◽  
Medical Implants ◽  
Field Exposure ◽  
Maximum Enhancement ◽  
Medical Implant ◽  
Measurement Results ◽  
Simulation Results

This paper presents the effects of conductive medical implant on energy absorbed by the human body and the testicular area when exposed to near field electromagnetic radiation. A dipole antenna is used as the radiating source and it is placed in front of the trousers pocket. Two types of medical implants are used in this study: intramedullary nail and bone plate. Numerical simulations are performed by means of CST Microwave Studio. Results are discussed in terms of changes in SAR values due to the presence of conductive medical implant at 0.4, 0.9, 1.8 and 2.4 GHz. The results have indicated that the conductive intramedullary nail that is located inside the femur significantly increases the SAR. Maximum enhancement in SAR is found when the length of the intramedullary nail is approximately one wavelength of the respective frequency tested. The measurement results indicate good agreements with the simulation results at 2.4 GHz.

scholarly journals Design and SAR assessment of three compact 5G antenna arrays

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Lak ◽  
Z. Adelpour ◽  
H. Oraizi ◽  
N. Parhizgar
Keyword(s):  
Antenna Arrays ◽  
Millimeter Waves ◽  
Reasonable Agreement ◽  
Specific Absorption Rate ◽  
Human Head ◽  
Head Model ◽  
Measurement Results ◽  
Exposure Source ◽  
Simulation Results ◽  
The Brain

AbstractIn this paper three different multi stub antenna arrays at 27–29.5 GHz are designed. The proposed antenna arrays consist of eight single elements. The structure of feeding parts is the same but the radiation elements are different. The feeding network for array is an eight way Wilkinson power divider (WPD). To guarantee the simulation results, one of the proposed structures is fabricated and measured (namely the characteristics of S11, E-, and H-plane patterns) which shows acceptable consistency with measurement results. The simulation results by CST and HFSS show reasonable agreement for reflection coefficient and radiation patterns in the E- and H- planes. The overall size of the proposed antenna in maximum case is 29.5 mm × 52 mm ×  0.38 mm  (2.8 $${{\varvec{\lambda}}}_{0}$$ λ 0 × 4.86$${{\varvec{\lambda}}}_{0}$$ λ 0 × 0.036$${{\varvec{\lambda}}}_{0}$$ λ 0 ). Moreover, for Specific Absorption Rate (SAR) estimation, a three-layer spherical human head model (skin, skull, and the brain) is placed next to the arrays as the exposure source. The simulation results show that the performance of proposed antennas as low-SAR sources makes them ideal candidates for the safe usage and lack of impact of millimeter waves (mmW) on the human health. In all three cases of SAR simulations the value of SAR1g and SAR10g are below the standard limitations.

Direction of Arrival Estimation Under Near-Field Interference Using Matrix Filter

2015 ◽  
Vol 23 (04) ◽  
pp. 1540007 ◽  
Author(s):  
Guolong Liang ◽  
Wenbin Zhao ◽  
Zhan Fan
Keyword(s):  
Near Field ◽  
Direction Of Arrival ◽  
Doa Estimation ◽  
Direction Of Arrival Estimation ◽  
Far Field ◽  
Data Simulation ◽  
Estimation Algorithms ◽  
Simulation Results

Direction of arrival (DOA) estimation is of great interest due to its wide applications in sonar, radar and many other areas. However, the near-field interference is always presented in the received data, which may result in degradation of DOA estimation. An approach which can suppress the near-field interference and preserve the far-field signal desired by using a spatial matrix filter is proposed in this paper and some typical DOA estimation algorithms are adjusted to match the filtered data. Simulation results show that the approach can improve capability of DOA estimation under near-field inference efficiently.

scholarly journals Modeling of German Low Voltage Cables with Ground Return Path

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1265 ◽  
Author(s):  
Johanna Geis-Schroer ◽  
Sebastian Hubschneider ◽  
Lukas Held ◽  
Frederik Gielnik ◽  
Michael Armbruster ◽  
...  
Keyword(s):  
Low Voltage ◽  
Measurement Data ◽  
Analytical Calculation ◽  
Laboratory Measurement ◽  
Model Parameters ◽  
Calculation Methods ◽  
Modeling Approach ◽  
Measurement Results ◽  
Simulation Results ◽  
Return Path

In this contribution, measurement data of phase, neutral, and ground currents from real low voltage (LV) feeders in Germany is presented and analyzed. The data obtained is used to review and evaluate common modeling approaches for LV systems. An alternative modeling approach for detailed cable and ground modeling, which allows for the consideration of typical German LV earthing conditions and asymmetrical cable design, is proposed. Further, analytical calculation methods for model parameters are described and compared to laboratory measurement results of real LV cables. The models are then evaluated in terms of parameter sensitivity and parameter relevance, focusing on the influence of conventionally performed simplifications, such as neglecting house junction cables, shunt admittances, or temperature dependencies. By comparing measurement data from a real LV feeder to simulation results, the proposed modeling approach is validated.

scholarly journals Multi-Probe Measurement System Based on Single-Cut Transformation for Fast Testing of Linear Arrays

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1744
Author(s):  
Fernando Rodríguez Varela ◽  
Manuel José López Morales ◽  
Rubén Tena Sánchez ◽  
Alfonso Tomás Muriel Barrado ◽  
Elena de la Fuente González ◽  
...  
Keyword(s):  
Measurement System ◽  
Near Field ◽  
Linear Measurement ◽  
Complete Characterization ◽  
Linear Arrays ◽  
Full Characterization ◽  
X Band ◽  
Measurement Results ◽  
The Many ◽  
3D Information

This paper introduces a near-field measurement system concept for the fast testing of linear arrays suited for mass production scenarios where a high number of nominally identical antennas needs to be measured. The proposed system can compute the radiation pattern, directivity and gain on the array plane, as well as the array complex feeding coefficients in a matter of seconds. The concept is based on a multi-probe antenna array arranged in a line which measures the near field of the antenna under test in its array plane. This linear measurement is postprocessed with state-of-the-art single-cut transformation techniques. To compensate the lack of full 3D information, a previous complete characterization of a “Gold Antenna” is performed. This antenna is nominally identical to the many ones that will be measured with the proposed system. Therefore, the data extracted from this full characterization can be used to complement the postprocessing steps of the single-cut measurements. An X-band 16-probe demonstrator of the proposed system is implemented and introduced in this paper, explaining all the details of its architecture and operation steps. Finally, some measurement results are given to compare the developed demonstrator with traditional anechoic measurements, and show the potential capabilities of the proposed concept to perform fast and reliable measurements.

scholarly journals A System in Package Based on a Piezoelectric Micromachined Ultrasonic Transducer Matrix for Ranging Applications

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2590
Author(s):  
Alexandre Robichaud ◽  
Dominic Deslandes ◽  
Paul-Vahé Cicek ◽  
Frederic Nabki
Keyword(s):  
High Voltage ◽  
Integrated Circuit ◽  
Ultrasonic Transducer ◽  
Ultrasonic Transducers ◽  
Transimpedance Amplifier ◽  
Measurement Results ◽  
Ultrasonic Ranging ◽  
High Voltage Pulser ◽  
Working Frequency ◽  
Simulation Results

This paper proposes a system in package (SiP) for ultrasonic ranging composed of a 4 × 8 matrix of piezoelectric micromachined ultrasonic transducers (PMUT) and an interface integrated circuit (IC). The PMUT matrix is fabricated using the PiezoMUMPS process and the IC is implemented in the AMS 0.35 µm technology. Simulation results for the PMUT are compared to the measurement results, and an equivalent circuit has been derived to allow a better approximation of the load of the PMUT on the IC. The control circuit is composed of a high-voltage pulser to drive the PMUT for transmission and of a transimpedance amplifier to amplify the received echo. The working frequency of the system is 1.5 MHz.

scholarly journals Drugs, Active Ingredients and Diseases Database in Spanish. Augmenting the Resources for Analyses on Drug–Illness Interactions

Data ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 3
Author(s):  
Irene López-Rodríguez ◽  
César F. Reyes-Manzano ◽  
Israel Reyes-Ramírez ◽  
Tania J. Contreras-Uribe ◽  
Lev Guzmán-Vargas
Keyword(s):  
Side Effects ◽  
Near Field ◽  
Quantitative Information ◽  
Active Pharmaceutical Ingredients ◽  
Sources Of Information ◽  
Active Ingredients ◽  
Field Exposure ◽  
Essential Information ◽  
Pharmaceutical Ingredients ◽  
Active Substances

Quantitative and qualitative data on active-ingredient drug composition are essential information for characterizing near-field exposure of consumers to product-related chemicals, among other things. Equally as important is the characterization of the relationship between one or many active ingredients in terms of the diseases they are prescribed for. Such evaluations, however, require quantitative information at different anatomical levels. To complement the available sources of information on active substances and diseases, we have designed a database with enough versatility to potentially be used in a variety of analyzes. By using information provided by a well-established online pharmacological dictionary, we present a database with 11 tables which are easy to access and manipulate. Specifically, we present datasets containing the details of 12,827 marketed drug products, 40,164 diseases, 6231 active pharmaceutical ingredients and 4093 side effects. We exemplify the usefulness of our database with three simple visualizations, which confirm the importance of the data for quantifying the complexity in the associations among active substances, diseases and side effects. Although there are databases with detailed information on active substances and diseases, none of them can be found in Spanish. Our work presents an option that contributes substantially to obtaining well classified information in order to evaluate the roles of active pharmaceutical ingredients, diseases and side effects. These datasets also provide information about clinical and pharmacological groupings which may be useful for clinical and academic researchers. The database will be regularly updated and extended with the newly available Virtual Medicinal Products.

Design of Broadband LNA Using Improved Self-Bias Architecture

2019 ◽  
Vol 28 (08) ◽  
pp. 1920005 ◽  
Author(s):  
Tian Qi ◽  
Songbai He
Keyword(s):  
Noise Figure ◽  
Low Noise ◽  
Power Gain ◽  
Matching Networks ◽  
Self Bias ◽  
Measurement Results ◽  
Chip Size ◽  
Simulation Results ◽  
Noise Amplifier ◽  
Ku Band

A broadband low-noise amplifier (LNA) using 0.13 [Formula: see text]m GaAs HEMT technology for Ku-band applications is presented in this paper. By introducing an improved self-bias architecture, the LNA is achieved with low noise figure (NF) and high power gain. Compared with traditional LNA, self-bias architecture can reduce DC supplies to single one, and the improved architecture proposed here also takes part in source matching to reduce the complexity matching networks for broadband applications. To verify, an LNA operating over 12–18-GHz bandwidth is fabricated. The measurement results, for all the 72 chips on the wafer, and their average values are in great accordance with the simulation results, with 25.5–27.5-dB power gain, 1.1–1.8-dB NF, 15–17.5-dBm output power at [Formula: see text] and with a chip size of 2 mm [Formula: see text] 1.5 mm.

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