scholarly journals A Design Rule to Reduce the Human Body Effect on Wearable PIFA Antennas

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 244 ◽  
Author(s):  
Giovanni Casula ◽  
Giorgio Montisci
Keyword(s):  
Human Body ◽  
Magnetic Energy ◽  
Ground Plane ◽  
Electric Energy ◽  
Design Rule ◽  
Simulation Environment ◽  
Body Effect ◽  
Minimal Impact ◽  
Optimal Extension ◽  
Difficult Challenge

The robustness of wearable Ultra-High Frequency (UHF)-band planar inverted-F Antennas (PIFAs) with respect to coupling with the human body is an extremely difficult challenge for the designer. In this work a design strategy is presented to help the designer to adequately shape and extend the antenna ground plane, which has been derived by accurately analyzing the distribution of the electric and magnetic energy densities of the antenna in a region around the antenna borders. The optimal extension of the ground plane will be discussed for three different grounded antennas, both in terms of free space wavelength, and in terms of electric energy density magnitude. Following these rules, the antenna robustness with respect to the coupling with the human body can be significantly improved, but with a minimal impact on the antenna size. The antenna robustness has been successfully tested considering several models for the human phantom in the simulation environment. The numerical simulations, performed using Computer Simulation Technology (CST) Microwave Studio, have been confirmed by experimental data measured for one of the analyzed grounded antenna configurations.

scholarly journals Correction: Casula, G.A. A Design Rule to Reduce the Human Body Effect on Wearable PIFA Antennas. Electronics 2019, 8, 244

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 291
Author(s):  
Giovanni Casula ◽  
Giorgio Montisci
Keyword(s):  
Human Body ◽  
Original Version ◽  
Design Rule ◽  
Body Effect

In the original version of this article [...]

A numerical assessment of the human body effect in the transmission of wireless microphones

2018 ◽  
Vol 61 (3) ◽  
pp. 809-817
Author(s):  
Eugenia Cabot ◽  
Ivica Stevanovic ◽  
Niels Kuster ◽  
Myles H. Capstick
Keyword(s):  
Human Body ◽  
Body Effect ◽  
Numerical Assessment

scholarly journals Numerical Evaluation and Experimental Test on a New Giant Magnetostrictive Transducer with Low Heat Loss Design

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1397
Author(s):  
Zhuan Bai ◽  
Zonghe Zhang ◽  
Ju Wang ◽  
Xiaoqing Sun ◽  
Wei Hu
Keyword(s):  
Heat Loss ◽  
Temperature Rise ◽  
Magnetic Energy ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Energy Utilization ◽  
Element Analysis ◽  
Excessive Heat ◽  
Excitation Coil ◽  
Magnetostrictive Transducer

Giant magnetostrictive transducer with micro and nano precision has a wide application prospect in the field of remote sensing. However, excessive heat loss of components could generate during the energy conversion and transfer from electric energy to magnetic energy, and magnetic energy to mechanical energy, thereby affecting its long-term service and also reducing energy utilization. In this paper, a new magnetostrictive transducer is proposed and its excitation coil, internal and external magnetic circuit are optimized from the perspective of reducing heat loss. With the help of theoretical and finite element analysis, the response law between key parameters and heat loss of key components are summarized, which provides a basis for reducing heat loss. Finally, according to the optimization scheme, the prototype is processed, and the temperature rise and dynamic output performance of the transducer are tested by constructing an experimental setup. The results show that the transducer has a low temperature rise and good frequency response characteristics, which can provide support for long-time precise actuation on-orbit.

Transmission Line

2020 ◽  
pp. 43-71
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Magnetic Energy ◽  
Propagation Constant ◽  
Characteristic Impedance ◽  
Electric Energy ◽  
Electromagnetic Energy ◽  
The Other ◽  
Electrical Characteristics ◽  
Lumped Elements

A transmission line (TL) is simply a medium that is capable of guiding or propagating electromagnetic energy. The transmission line stores the electric (E) and magnetic (M) energies and distributes them in space by alternating them between the two forms. This means that at any point along a TL, energy is stored in a mixture of E and M forms and, for an alternating signal at any point on the TL, converted from one form to the other as time progresses. Transmission line is usually modelled using lumped elements (i.e., inductors for magnetic energy, capacitors for electric energy, and resistors for modelling losses). The electrical characteristics of a TL such as the propagation constant, the attenuation constant, the characteristic impedance, and the distributed circuit parameters can only be determined from the knowledge of the fields surrounding the transmission line. This chapter gives a brief overview of various transmission lines, with more detailed discussions on the microstrip and the SIW.

scholarly journals An Efficient Full-Wave Electromagnetic Analysis for Capacitive Body-Coupled Communication

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Muhammad Irfan Kazim ◽  
Muhammad Imran Kazim ◽  
J. Jacob Wikner
Keyword(s):  
Human Body ◽  
Ground Plane ◽  
Propagation Loss ◽  
Communication Link ◽  
Simulation Approach ◽  
Full Wave ◽  
The Earth ◽  
Measurement Results ◽  
Link Budget ◽  
Physiological Variations

Measured propagation loss for capacitive body-coupled communication (BCC) channel (1 MHz to 60 MHz) is limitedly available in the literature for distances longer than 50 cm. This is either because of experimental complexity to isolate the earth-ground or design complexity in realizing a reliable communication link to assess the performance limitations of capacitive BCC channel. Therefore, an alternate efficient full-wave electromagnetic (EM) simulation approach is presented to realistically analyze capacitive BCC, that is, the interaction of capacitive coupler, the human body, and the environment all together. The presented simulation approach is first evaluated for numerical/human body variation uncertainties and then validated with measurement results from literature, followed by the analysis of capacitive BCC channel for twenty different scenarios. The simulation results show that the vertical coupler configuration is less susceptible to physiological variations of underlying tissues compared to the horizontal coupler configuration. The propagation loss is less for arm positions when they are not touching the torso region irrespective of the communication distance. The propagation loss has also been explained for complex scenarios formed by the ground-plane and the material structures (metals or dielectrics) with the human body. The estimated propagation loss has been used to investigate the link-budget requirement for designing capacitive BCC system in CMOS sub-micron technologies.

scholarly journals Optimization of UHF RFID Five-Slotted Patch Tag Design Using PSO Algorithm for Biomedical Sensing Systems

2020 ◽  
Vol 17 (22) ◽  
pp. 8593
Author(s):  
Ibtissame Bouhassoune ◽  
Abdellah Chehri ◽  
Rachid Saadane ◽  
Khalid Minaoui
Keyword(s):  
Human Body ◽  
Radio Frequency Identification ◽  
Flexible Substrate ◽  
Ground Plane ◽  
Pso Algorithm ◽  
Uhf Rfid ◽  
Biomedical Sensing ◽  
Sensing Applications ◽  
Human Arm ◽  
Frequency Identification

In this paper, a new flexible wearable radio frequency identification (RFID) five-shaped slot patch tag placed on the human arm is designed for ultra-high frequency (UHF) healthcare sensing applications. The compact proposed tag consists of a patch structure provided with five shaped slot radiators and a flexible substrate, which minimize the human body’s impact on the antenna radiation performance. We have optimized our designed tag using the particle swarm optimization (PSO) method with curve fitting within MATLAB to minimize antenna parameters to achieve a good return loss and an attractive radiation performance in the operating band. The PSO-optimized tag’s performance has been examined over the specific placement in some parts of the human body, such as wrist and chest, to evaluate the tag response and enable our tag antenna conception in wearable biomedical sensing applications. Finally, we have tested the robustness of this tag by evaluating its sensitivity as a function of the antenna radiator placement over the ground plane or by shaping the ground plane substrate for the tag’s position from the human body. Our numerical results show an optimal tag size with good matching features and promising read ranges near the human body.

A reactance theorem

1977 ◽  
Vol 353 (1672) ◽  
pp. 1-10 ◽  
Keyword(s):  
Magnetic Energy ◽  
Electric Energy ◽  
Electromagnetic System ◽  
Energy Radiation ◽  
Physical Attributes ◽  
Time Average ◽  
Time Invariant ◽  
System Time

A formula is derived for the frequency derivative of the input reactance of any linear, passive, time-invariant electromagnetic system. It consists of five terms, each of which is identifiable uniquely with one of the following five physical attributes of the system: time-average stored magnetic energy, time-average stored electric energy, radiation, dispersion by the medium, and dissipation by the medium.

scholarly journals Human Body Effect on Static UWB WBAN Off-Body Radio Channels

2020 ◽  
pp. 17-25
Author(s):  
Timo Kumpuniemi ◽  
Juha-Pekka Mäkelä ◽  
Matti Hämäläinen ◽  
Kamya Yekeh Yazdandoost ◽  
Jari Iinatti
Keyword(s):  
Human Body ◽  
Body Effect ◽  
Radio Channels
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