Improving Performance by Countering Human Body Shadowing in 60GHz Band Wireless Systems by Using Two Transmit and Two Receive Antennas

The global spread of 5th generation (5G) wireless systems causes some concern about health effects of millimeter waves (MMW). To investigate biological effects of local exposure to 5G-MMW on human body, a novel 60 GHz band exposure setup was developed, and its performance was validated. A spatial synthetic beam-type exposure setup using two dielectric lens antennas was proposed to achieve high intensity 60 GHz irradiation to the target area of human skin. Variety distributions and intensities of electromagnetic fields at the exposed area, which is modified by incident angles of the combined beams, were simulated using finite-difference time-domain methods. The exposure performance we estimated was verified by temperature elevations of surface in a physical arm-shaped silicone phantom during the MMW exposure. The interference fringes generated in the exposed area due to the combined two-directional beam radiations were observed both in the simulation and in the phantom experiment but eliminated by applying an orthogonalizing polarized feeding structure. Under these exposure conditions, the local temperature changes, which could evoke warmth sensations, were obtained at the target area of the human forearm skin, which means the achievement of exposure performance we intended.

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Model for Ray-Based UTD Simulations of the Human Body Shadowing Effect in 5G Wireless Systems

International Journal of Antennas and Propagation ◽

10.1155/2018/9084830 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Łukasz Januszkiewicz

Keyword(s):

Human Body ◽

Communication Systems ◽

Path Loss ◽

Wireless Systems ◽

Wireless Communication Systems ◽

Human Body Model ◽

Uniform Theory Of Diffraction ◽

Indoor Wireless ◽

Shadowing Effect ◽

Difference Time

Shadowing effects caused by the obstructing presence of a human body can result in increased path loss in indoor wireless systems. This paper proposes a simplified model of a human body for use in ray-tracing simulations of indoor wireless communication systems based on the uniform theory of diffraction (UTD). The human body shadowing effect was first investigated using measurements and computer simulations employing the finite-difference time-domain method (FDTD). Based on the results, a human body model was elaborated for use in ray-based Remcom XGtd software. The model was developed for the 3.6 GHz band, which has been allocated for 5G wireless systems in many countries.

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A New Approach and Analysis of Modeling the Human Body in RFID-Enabled Body-Centric Wireless Systems

International Journal of Antennas and Propagation ◽

10.1155/2014/368090 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 6

Author(s):

Karoliina Koski ◽

Toni Björninen ◽

Lauri Sydänheimo ◽

Leena Ukkonen ◽

Yahya Rahmat-Samii

Keyword(s):

Human Body ◽

Human Subjects ◽

Impedance Matching ◽

Wireless Systems ◽

Human Model ◽

Communication Link ◽

Uhf Rfid ◽

Human Body Model ◽

Design And Optimization ◽

Wide Range

Body-centric wireless systems demand wearable sensor and tag antennas that have robust impedance matching and provide enough gain for a reliable wireless communication link. In this paper, we discuss a novel and practical technique for the modeling of the human body in UHF RFID body-centric wireless systems. What makes this technique different is that we base the human model on measured far-field response from a reference tag attached to the human body. Hereby, the human body model accounts for the encountered human body effects on the tag performance. The on-body measurements are fast, which allows establishing a catalog of human body models for different tag locations and human subjects. Such catalog would provide a ready simulation model for a wide range of wireless body-centric applications in order to initiate a functional design. Our results demonstrate that the suggested modeling technique can be used in the design and optimization of wearable antennas for different real-case body-centric scenarios.

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Microstructural comparison of synthetic bioceramics with natural bioceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084491 ◽

1991 ◽

Vol 49 ◽

pp. 38-39

Author(s):

Shulin Wen ◽

Jingwei Feng ◽

A. Krajewski ◽

A. Ravaglioli

Keyword(s):

Recent Work ◽

Human Body ◽

Human Tissues ◽

Main Constituent ◽

Laboratory Furnace ◽

Chinese Adult ◽

Human Enamel ◽

Biological Compatibility ◽

Synthetic Hydroxyapatite ◽

Synthetic Work

Hydroxyapatite bioceramics has attracted many material scientists as it is the main constituent of the bone and the teeth in human body. The synthesis of the bioceramics has been performed for years. Nowadays, the synthetic work is not only focused on the hydroapatite but also on the fluorapatite and chlorapatite bioceramics since later materials have also biological compatibility with human tissues; and they may also be very promising for clinic purpose. However, in comparison of the synthetic bioceramics with natural one on microstructure, a great differences were observed according to our previous results. We have investigated these differences further in this work since they are very important to appraise the synthetic bioceramics for their clinic application.The synthetic hydroxyapatite and chlorapatite were prepared according to A. Krajewski and A. Ravaglioli and their recent work. The briquettes from different hydroxyapatite or chlorapatite powders were fired in a laboratory furnace at the temperature of 900-1300°C. The samples of human enamel selected for the comparison with synthetic bioceramics were from Chinese adult teeth.

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Study on erythrocytes by SEM photogrammetry (SEMP) technique

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100161187 ◽

1990 ◽

Vol 48 (3) ◽

pp. 724-725

Author(s):

Tong Wensheng ◽

Lu Lianhuang ◽

Zhang Zhijun

Keyword(s):

Quantitative Analysis ◽

Cell Membrane ◽

Clinical Diagnosis ◽

Human Body ◽

Blood Cells ◽

Three Dimensional ◽

Normal Person ◽

Blood Disease ◽

Computation Technique ◽

Important Basis

This is a combined study of two diffirent branches, photogrammetry and morphology of blood cells. The three dimensional quantitative analysis of erythrocytes using SEMP technique, electron computation technique and photogrammetry theory has made it possible to push the study of mophology of blood cells from LM, TEM, SEM to a higher stage, that of SEM P. A new path has been broken for deeply study of morphology of blood cells.In medical view, the abnormality of the quality and quantity of erythrocytes is one of the important changes of blood disease. It shows the abnormal blood—making function of the human body. Therefore, the study of the change of shape on erythrocytes is the indispensable and important basis of reference in the clinical diagnosis and research of blood disease.The erythrocytes of one normal person, three PNH Patients and one AA patient were used in this experiment. This research determines the following items: Height;Length of two axes (long and short), ratio; Crevice in depth and width of cell membrane; Circumference of erythrocytes; Isoline map of erythrocytes; Section map of erythrocytes.

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