• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.25-31
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• 2014

In this paper, a modified Alford loop antenna for on-body communication system is proposed. The proposed antenna operating in the ISM band is designed with consideration of human body effect. One of advantages of the Alford loop antenna structure is low-profile, however the Alford loop antenna is not suitable for on-body devices since it does not have a ground plane for other electronic part of on-body system and requires balanced feeding structure. To be embedded on on-body devices, the proposed antenna is design with the unbalanced feed structure and ground. The performance of the proposed antenna is simulated and measured when it is placed on the human body phantom to consider the effect of the human body. The proposed antenna a 10 dB return loss bandwidth over the ISM band and monopole-like radiation pattern with low-profile. The antenna has the surface of appropriate for on-body communication environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.9
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• pp.841-851
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• 2014

Wireless technologies sharing the same frequency band and operating in the same environment often interfere with each other, causing severe decrease in performance. In this paper, we propose a algorithm based on traffic scheduling techniques that mitigate interference between different wireless systems operating in the 2.4-GHz industrial, medical, and scientific band. In particular, we consider IEEE 802.11 wireless local area networks (WLANs) and Bluetooth data transfer, showing that the proposed algorithms can work when the two systems are able to exchange information as well as when they operate independently of one another. Results indicate that the proposed algorithm remarkably mitigate the interference between the WLAN and Bluetooth technologies at the expense of a small additional delay in the data transfer.

• Journal of Satellite, Information and Communications
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• v.11 no.4
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• pp.33-38
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• 2016

As a communications system and using the wireless devices is increased at the world, the interference among devices at 2.4GHz band become issue. New complex content technology as education, concert, broadcast, thema-park are developed between Virtual Reality technology and tradition. That is expect an annual growth rate of more than 14%. Almost Virtual Reality devices use motion sense or a wireless joystick. Therefore it is necessarily to analyze the coexistence between Virtual Reality devices and Wi-Fi in the ISM band. The interference scenario and propagation of the Extended Hata Model was established to analyze the interference from WLAN into Virtual Reality devices. Through simulation results based on Monte-Carlo principle, separation frequency was obtained to protect WLAN interference from Virtual Reality devices.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11B
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• pp.1612-1619
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• 2001

This paper examines the design, implementation characteristics of a folded dipole active integrated antenna. Our goal was to minimize the physical size of RF circuit and its insertion loss, and to make the high frequency tuning easier by directly integrating the ISM(Industrial Scientific & Medical) band power amplifier and antenna. Non-linear model has been used for highly accurate simulation of the power amplifier. The maximum power level was found by using the Load pull method before an impedance matching was achieved. It is found that the total power-added efficiency(PAE) including the driving amplifier was 31.5% and that the transmit power was 13.7 dBm. We also found that the proposed scheme with the smaller antenna as compared with the existing dipole antenna has 23.7 dB total gain including the antenna gain. The suppression of the second harmonic signal to the fundamental signal with respect to the fundamental signal was found to be more than 30 dBc.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.2
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• pp.136-144
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• 2006

This research evaluated how the composition of Yak-sun(oriental diet therapy), taken as a nutritional supplement with daily meals, can effect the medical condition of those suffering from modern diseases like obesity and hyperlipideia. We produced Yak-sun tea, determined its nutrient composition and physical characteristics and evaluated how this tea effects affects the active oxygen concentration inside the body by clinical practices. The study results indicated that this tea significantly decrease active oxygen concentration. We think that scientific and objective evaluation was done on the components of Yak-sun tea prescription. We concluded that we could apply the components not only in the form of tea, but also in other food forms. The information we received from this conclusion will provide basic information for the application of oriental medicinal resources into other foods and will also be a steppingstone in the field of functional food research for the development of medicinal herbs which is already an important research field world-wide.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.440-443
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• 2007

In this paper, microstrip antenna is designed for industrial-scientific-medical(ISM)band of S-Band. We proposed that radiation element of antenna, which is rectangle patch shape. The feeding structure used L-shaped structure. Center frequency and -l0dB bandwidth are investigated by change of length and width in patch plane. And maximum gain, front to back ratio and 3dB beam width is presented by simulation radiation pattern of antenna in frequency ISM Band. The center frequency is 2.45GHz, band width is $2.314{\sim}2.577GHz$ with 263MHz(11%). And the antenna maximum gain is 9.3dBi, 3dB beam width E-plane is $52.5^{\circ}$, H-plane is $64.7^{\circ}$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.11
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• pp.1133-1136
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• 2011

In this paper, we proposed a collinear antenna with a stripline structure for IEEE 802.11b/g applications in ISM (Industrial, Scientific, Medical) band of 2.4~2.5 GHz, which supplements disadvantages of COCO(Coaxial Collinear) antenna and OMA(Omnidirectional planar Microstrip Antenna). By using the proposed 4-layer substrate, we obtained improved performances and advantages in production compared with the existing antenna. In order to get antenna arrays, the same phase structure is designed by alternatively connecting outer conductor to inner conductor with ${\lambda}$/2 antenna element, and the substrate of FR4 epoxy (${\epsilon}_r$=4.4, tan${\delta}$=0.02) was used for the actual implementation. The maximum gain of about 4.93 dBi was measured, which leaded to a little improved gain of 0.33 dBi in comparison to the existing OMA structure.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.589-595
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• 2007

Korea Railroad Research Institute has developed the driverless rubber-tired K-AGT (Korean-Automated Guideway Transit) system from 1999 to 2005 and has done its performance and reliability tests on the test line at Gyeongsan-city. Radio Frequency Communication-Based Train Control system of K-AGT, which employed Advanced Automated Train Control scheme, detects train position using the radio propagation delay between wayside and vehicle radio equipment. In this paper, we investigate whether the transmission power of radio system can be reduced to the permitted level announced by the Ministry of Information and Communication for license-free ISM(Industrial Scientific Medical) frequency bands. We first determine radio propagation model, using the measured data at test line, and perform simulation for radio coverage prediction. From the simulation results, we identify that the radio system operated with reduced power can provide good link quality in total test line.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.12
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• pp.915-923
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• 2018

A concrete embedded antenna design is proposed for probing the durability of a building at an industrial scientific medical band of 902~908 MHz. The proposed antenna is designed with a stacked slot patch structure for lower impedance variation to a dielectric constant of concrete, as a dielectric constant difference is derived from the moisture content. The proposed structure has a wider bandwidth when a parasitic patch structure is used, which reduces antenna performance degradation resulting from the moisture content of concrete. The measured voltage standing wave ratio of the proposed structure is less than 2 and the beam width is approximately $80^{\circ}$, whereas the gain is greater than 7 dBi. The proposed antenna is fabricated with a rectangle-type concrete block, which is simulated and measured for return loss and antenna gain.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.6
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• pp.515-519
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• 2015

In this paper, we suggested the novel monopole antenna for dual band characteristics by a linear monopole antenna combined with crossed planar monopole antenna. The target frequency is ISM(Industrial Scientific Medical) 2.45GHz/5.8GHz. The distinctive features of the proposed antenna in this paper is based on the slit in the surface of a crossed planar monopole for the dual band characteristics and the omnidirectional radiation patterns. The compact size of the proposed antenna is $36mm{\times}5.4mm{\times}5.4mm$. According to the simulation results, the bandwidth, the reflection coefficients below -10dB, of 2.45GHz and 5.8GHz are 150MHz and 1.43GHz, respectively. Consequently the proposed antenna structures is apply to the antenna for dual band characteristics.