scholarly journals A Novel Dual-Band Implantable Antenna for Pancreas Telemetry Sensor Applications

Telecom ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 1-16
Author(s):  
Maria Matthaiou ◽  
Stavros Koulouridis ◽  
Stavros Kotsopoulos
Keyword(s):  
Finite Difference Time Domain ◽  
Specific Absorption Rate ◽  
Input Power ◽  
Dual Band ◽  
Electrical Field ◽  
Sensor Applications ◽  
Radiated Power ◽  
Implantable Antenna ◽  
Numerical Solver ◽  
Difference Time

In this study, a novel implantable dual-band planar inverted F-antenna (PIFA) is proposed and designed for wireless biotelemetry. The developed antenna is intended to operate on the surface of the pancreas within the Medical Device Radiocommunications Service (MedRadio 401–406 MHz) and the industrial scientific and medical band (ISM, 2.4–2.5 GHz). The design analysis was carried out in two steps, initially inside a canonical model representing the pancreas, based on a finite element method (FEM) numerical solver. The proposed antenna was further simulated inside the human body taking into account the corresponding dimensions of the tissues and the electrical properties at the frequencies of interest using a finite-difference time-domain (FDTD) numerical solver. Resonance, radiation performance, electrical field attenuation, total radiated power, and specific absorption rate (SAR), which determines the safety of the patient and the maximum permissible input power and other electromagnetic parameters, are presented and evaluated.

scholarly journals A New Design of Metamaterials for SAR Reduction

2013 ◽  
Vol 13 (2) ◽  
pp. 70-74 ◽  
Author(s):  
M. R. I. Faruque ◽  
M. T. Islam ◽  
M. A. M. Ali
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Fdtd Method ◽  
Cellular Phone ◽  
Drude Model ◽  
Specific Absorption ◽  
Difference Time

The purpose of this paper is to calculate the reduction of specific absorption rate (SAR) with a new design of square metamaterials (SMMs). The finite-difference time-domain (FDTD) method with lossy-Drude model is adopted in this analysis. The method of SAR reduction is discussed and the effects of location, distance, and size of metamaterials are analyzed. SMMs have achieved a 53.06% reduction of the initial SAR value for the case of 10 gm SAR. These results put forward a guideline to select various types of metamaterials with the maximum SAR reducing effect for a cellular phone.

SAR and Temperature Evaluations of a 900 Mhz TEM Chamber for Cell Exposure

2012 ◽  
Vol 195-196 ◽  
pp. 90-95
Author(s):  
Z. Ren ◽  
J.X. Zhao ◽  
H.M. Lu ◽  
J.N. Zhang ◽  
W. Wang
Keyword(s):  
Finite Difference ◽  
Temperature Rise ◽  
Finite Difference Time Domain ◽  
Maxwell Equations ◽  
Specific Absorption Rate ◽  
Cultured Cells ◽  
Petri Dish ◽  
Transverse Electromagnetic ◽  
Difference Time

A dosimetry study is made for experiments on cultured cells exposed to 900 MHz microwave in the transverse electromagnetic (TEM) chamber. The exposure is characterized by the intensity and homogeneity of the specific absorption rate (SAR), as well as the exposure-induced temperature rise. The SAR distribution is calculated by using the finite-difference time-domain (FDTD) algorithm of the Maxwell equations. The finite-difference formulation of the bioheat conduction equation is used to calculate the temperature rise of the in vitro environment. Evaluations of the SAR and temperature are performed systematically for scenarios including two formations of cultured cells, two maximum fields, and four polarizations of the Petri dish holding the cell culture. The exposure is optimized by selecting scenarios with the highest SAR intensity, the best SAR homogeneity, and the effective temperature control.

scholarly journals A compact dual-band semi-flexible antenna at 2.45 GHz and 5.8 GHz for wearable applications

2021 ◽  
Vol 10 (3) ◽  
pp. 1739-1746
Author(s):  
S. M. Shah ◽  
A. A. Rosman ◽  
M. A. Z. A. Rashid ◽  
Z. Z. Abidin ◽  
F. C. Seman ◽  
...  
Keyword(s):  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Flexible Substrate ◽  
Input Power ◽  
Substrate Material ◽  
Dual Band ◽  
Reflection Coefficients ◽  
Resonant Frequencies ◽  
Low Profile ◽  
Flexible Antenna

In this work, a compact dual-band semi-flexible antenna operating at         2.45 GHz and 5.8 GHz for the industrial, scientific and medical (ISM) band is presented. The antenna is fabricated on a semi-flexible substrate material, Rogers Duroid RO3003™ with a low-profile feature with dimensions of 30×38 mm2 which makes it a good solution for wearable applications. Bending investigation is also performed over a vacuum cylinder and the diameters are varied at 50 mm, 80 mm and 100 mm, that represents the average human arm’s diameter. The bending investigation shows that reflection coefficients for all diameters are almost similar which imply that the antenna will operate at the dual-band resonant frequencies, even in bending condition. The simulated specific absorption rate (SAR) in CST MWS® software shows that the antenna obeys the FCC and ICNIRP guidelines for 1 mW of input power. The SAR limits at 2.45 GHz for 1 g of human tissue is simulated at 0.271 W/kg (FCC standard: 1.6 W/kg) while for 10 g is at 0.0551 W/kg (ICNIRP standard: 2 W/kg. On the other hand, the SAR limits at 5.8 GHz are computed at 0.202 W/kg for 1 g and 0.0532 W/kg for 10 g.

scholarly journals Computational Modeling of SAR and Heat Distribution in Lossy Medium at GSM Frequencies

2018 ◽  
Keyword(s):  
Spinal Cord ◽  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Spinal Cord Tissue ◽  
Specific Absorption ◽  
Lossy Medium ◽  
Difference Time

In recent years, institution has increased imposition of electromagnetic radiation in many applications. This radiation react with the human tissue and may lead to harmful and injurious effects on human health. However a finite difference thermal model of lossy medium as (spinal cord of human body) has been developed to calculate temperature rises generated in the spinal cord by radiation from cellular telephones with different frequencies. The natural metabolic heat production and the power density absorbed from the electromagnetic field have been evaluated. The specific absorption rate (SAR) was derived from a finite difference time domain model (FDTD) of the spinal cord. This is a numerical analysis is technique used for modeling computational electrodynamics. Aside from the specific absorption rate, through the exposure of radiation is an extremely important parameter while assessing the effects on spinal cord tissue. The heat distribution was calculated using the bioheat equation coupled with Maxwell's equation. A one dimensional finite difference time domain method has been used, some simulations for electromagnetic wave through the spinal cord tissue is made using software program. Also for the simulation, the dielectric properties supposed medium are directly taken by numerical program. Results show that electromagnetic fields penetrate the life tissues and attenuate fast to reach zero at large time steps. Specific absorption rate show maximum at the first boundary of tissue and becomes less value by using high frequency. The absorbent power and specific absorption rate show maximum at the interface of tissue, and the technique developed may be used to estimate temperature rises associated with specific absorption rate (SARs) for different types of radiation. Also, the results note that low-frequency waves have significantly affected the biological tissue.

Investigation of Hand Worn Jewellery Effects on the Specific Absorption Rate in the Human Head and Hand

2011 ◽  
Vol 110-116 ◽  
pp. 4559-4563
Author(s):  
Mohammad Islam Tariqul ◽  
Zainool Abidin Hafizah ◽  
Rashed Iqbal Faruque Mohammad ◽  
Misran Norbahiah
Keyword(s):  
Finite Difference ◽  
Mobile Device ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Fdtd Method ◽  
Human Head ◽  
Human Hand ◽  
Difference Time

The presence of hand could alter the energy absorbed in the human head. Hence, a study of the interaction between mobile device antennas and human head in the presence of metallic hand worn jewellery on human hand with different holding ways is investigated. A finite-difference time domain (FDTD) method has been performed by considering an internal PIFA antenna as the radiating source mounted at the top of a commercial clamshell phone positioned nearer the ear. With the introduction of hand-worn jewellery in variation parameters, there were perceptible effects on SAR variation in the human head. SAR distribution in the SAM head was found decreases due to different hand positions. Therefore, the head and in particular the hand may further impairment radiation performance of a mobile device.

scholarly journals Wearable Fabric Reconfigurable Beam-Steering Antenna for On/Off-Body Communication System

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Seonghun Kang ◽  
Chang Won Jung
Keyword(s):  
Specific Absorption Rate ◽  
Beam Steering ◽  
Beam Width ◽  
Input Power ◽  
The Body ◽  
Loop Antenna ◽  
Radiated Power ◽  
The Us ◽  
Half Power ◽  
Better Than

This paper presents a comparison of on-body performances between omnidirectional (loop antenna) and reconfigurable beam-steering antennas. Both omnidirectional and reconfigurable antennas were manufactured on the same fabric substrate and operated at the frequency band of the WLAN 802.11a (5.725–5.85 GHz). The reconfigurable antenna was designed to steer the beam directions. In order to implement the beam-steering capability, the antenna used two PIN diodes. The maximum beam directions of three states (states 0, 1, and 2) were steerable in theYZ-plane (h=2°, 28°, and 326°, resp.). The measured peak gains were 5.9–6.6 dBi and the overall half power beam width (HPBW) was 102°. The measured results of total radiated power (TRP) and total isotropic sensitivity (TIS) indicated that the communication efficiency of the reconfigurable beam steering antenna was better than that of the loop antenna. When the input power was 0.04 W (16 dBm), the simulated specific absorption rate (SAR) values of the reconfigurable beam steering antenna on the body were less than 0.979 W/kg (1 g tissue) in all states, satisfying the SAR criteria of the US.

Biological effect of SAR on the human head due to variation of dielectric properties at 1800 and 2450 MHz with different antenna substrate materials

2015 ◽  
Vol 22 (4) ◽  
Author(s):  
Mohammad Rashed Iqbal Faruque ◽  
Mohammad Tariqul Islam ◽  
Mohammad Habib Ullah
Keyword(s):  
Dielectric Properties ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Biological Effect ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Fdtd Method ◽  
Human Head ◽  
Substrate Material ◽  
Difference Time

AbstractThe aim of this study was to consider a possible discrepancy in electromagnetic (EM) absorption in the human head. The finite-difference time-domain (FDTD) method with the lossy Drude model was adopted in this study. Here, the permittivity and conductivity of all head tissues were increased from 10% to 20% except when not using the same exposure conditions. Recognizable mobile phone frequencies of 1800 and 2450 MHz were studied in this simulation. The increase of up to 20% in conductivity and permittivity and varied substrate material always caused an EM absorption variation of 32.59% for specific absorption rate (SAR) 1 g and 35.25% for SAR 10 g at 1800 MHz, and variation of 20.37% for SAR 1 g and 17.99% for SAR 10 g at 2450 MHz, respectively.

Effects of electromagnetic absorption toward a human head due to variation of its dielectric properties at 900 and 1900 MHz with different antenna substrates

2012 ◽  
Vol 19 (3) ◽  
pp. 271-277 ◽  
Author(s):  
Nur Aisyah Husni ◽  
Mohammad Rashed Iqbal Faruque ◽  
Mohammad Tariqul Islam ◽  
Norbahiah Misran ◽  
Nik Abdullah Nik Mohamed
Keyword(s):  
Dielectric Properties ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Specific Absorption Rate ◽  
Fdtd Method ◽  
Human Head ◽  
Helical Antenna ◽  
Electromagnetic Absorption ◽  
Increase With Increase ◽  
Difference Time

AbstractThe aim of this paper is to analyze the effects of electromagnetic (EM) energy absorption at 900 and 1900 MHz when the human head’s dielectric properties are varied. This radiation is measured in terms of specific absorption rate (SAR). The characteristics of the helical antenna and its substrates with variation of the human head dielectric properties were simulated via the finite-difference time domain (FDTD) method using the CST Microwave studio. The human head dielectric properties are manipulated by increasing and decreasing 10% and 20% of each dielectric property. In this study, SAR values increase with increase of the human head’s conductivity, while increase of permittivity and densities decreases it. A helical antenna with a substrate of FR4 resulted in higher SAR values in all frequencies. The head SAR values are higher in the upper frequency exposures. The helical antenna with a substrate of Rogers RO3006 (loss free) was found to be the best-tested substrate, which contributed toward much lower SAR values in all GSM frequency bands.

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