• Journal of IKEEE
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• v.12 no.4
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• pp.185-195
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• 2008

In this paper, PIFA(Planar Inverted F Antenna) which operates in PCS(Personal Communication System) band is designed and characteristics are investigated. Designed PIFA was installed in three types of handsets, folder, bar, slide, and the performance was evaluated. Head and hand phantom were added to make the most similar environment to real condition of mobile phone use, and influences on antenna performance were analyzed. The simulation results confirm radiation patterns are greatly changed and antenna efficiency is decreased by the effect of human body. Performance variation of the mobile handset antenna was observed as changing the angle between mobile handset and head phantom from $0^{\circ}$ to $2^{\circ},\;4^{\circ}$ to confirm the variation caused by the relative position of mobile handset and head phantom. Directivity was decreased gradually as the antenna goes away from head phantom, and showed the trend of increasing efficiency. But in the case of bar type, where the position of antenna is relatively close to head phantom, that trend didn't show. It was confirmed that the shape of handset has a great effect on the performance.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.5
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• pp.491-503
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• 2014

In this paper, a $TM_{31}$ higher order mode half circular-ring microstrip antenna with monopole-like radiation characteristic for on-body communication is proposed. By using shorting vias, $TM_{31}$ resonance mode was excited, while achieving compact low-profile antenna with monopole-like radiation characteristics. To overcome the narrow bandwidth of a patch antenna, a C-shape half ring patch with shorting vias having $TM_{31}$ mode is closely located around a half circular patch. For size reduction, half mode is adopted. The proposed antenna has the overall dimensions of $0.25{\lambda}_0{\times}0.46{\lambda}_0{\times}0.025{\lambda}_0$ at the industrial, scientific, and medical(ISM) 2.45 GHz band(2.4~2.485 GHz) and the 10-dB return loss is 4.24 % ranging from 2.38 to 2.49 GHz. To verify body effect, two-thirds muscle equivalent semi solid phantom was fabricated and used to measure the antenna performance. A communication link is analysed to investigate the effect of human-body movements and antenna locations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.5 s.236
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• pp.743-753
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• 2005

The model of azimuth driving servo system with a flexible antenna in a prototype gimbal has been derived in this work. The validity of the model is verified by comparing the result of the model with that of experiment. It is found that one should consider an antenna as a flexible body in case of modeling the dynamics of the gimbal with an antenna. It is also known that the effect of reducing backlash magnitude for extending the bandwidth in the system with a flexible antenna is smaller than the system with a stiff antenna. It is thought that the model-based design optimization of the gimbal with an antenna will be possible by virtue of the derived model, when a weight reduction and a bandwidth extension are required.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.1
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• pp.46-52
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• 2014

In this paper, we present a design of meander type microstrip patch antenna which has the best quality in RFID approved international standard of 910MHz broadband, usable in metal environment. In order to be fit into the commercial tag chip on the antenna, a square shaped feeder is installed on the main body as well as in the main body. In addition, a multi meander type patching element was designed in order to reduce the main body effectively. Three antennae, Cases 1, 2 and 3, were designed and compared in the areas of broad band width, effectiveness or recognition distance according to their sizes and number of folds. The measurement result of Case 3 was determined to be the best. It was confirmed that mostly the efficiency and characteristic gain change due to antenna size and number of folds in meander type influenced the antenna recognition distance.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.206-211
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• 2010

In this paper, an implantable planar inverted-F antenna (PIFA) for an artificial cardiac pacemaker is proposed. The antenna has a simple structure with a low profile and is placed on the top side of the pacemaker. The dimensions of the pacemaker system, including the antenna element, are $42{\times}43.6{\times}11$ mm. When the antenna is embedded in pig tissue, its $S_{11}$ value is -10.94 dB at 403 MHz and the -10 dB impedance bandwidth of the antenna is 6 MHz (399~406 MHz). The proposed PIFA in tissue has a peak gain of -20.19 dBi and a radiation efficiency of 1.12 % at 403 MHz. When the proposed antenna is placed in a flat phantom, its specific absorption ratio (SAR) value is 0.038 W/kg (1 g tissue). Performances of the proposed PIFA is sufficient to operate at the MICS band (402 ~ 405 MHz).

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.2
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• pp.135-140
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• 2008

In this paper, the spiral antenna with the center frequencies of 315MHz, 433MHz, and 447MHz for RKE system of a vehicle is designed on PCB. The antenna is microstrip line-fed, and applied PIFA concept near the feeding part to easily tune center frequency and input impedance. The PIFA-type spiral antenna with the size of $30mm{\times}20mm$ is designed on printed PCB by considering the effect of circuits and components on PCB, ECU case and vehicle body. Also chip inductor inserted dual-band spiral antenna of 315MHz and 447MHz is designed. We found that the antenna designed on PCB satisfied the antenna specifications through measurement and field test.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.6
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• pp.503-508
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• 2009

There are many researches on human effect by electromagnetic equipments and applications. However, most of research and guidelines for limiting human exposure to electromagnetic fields are established by mobile communication of SAR(Specific Absorption Ratio). Therefore we need to study different effects on human body when exposed to high frequency(HF) band equipments, such as human induced current etc. In this paper, we measured human induced current by RFID reader antenna of HF band in the near field and we propose human equivalent antenna which has orthogonal loops to each other. Then, we compared the induced currents on proposed equivalent antenna with human.

• Journal of Convergence Society for SMB
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• v.3 no.2
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• pp.27-32
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• 2013

Wireless Body Area Networks (WBAN) have been made possible by the emergence of small and lightweight wireless systems such as Bluetooth, enabled devices and PDAs. Antennas are an essential part of any WBAN system and due to various technical requirements and physical constraints, careful consideration of their design and deployment is needed. This paper is proposing on the design of wearable antenna as parts of clothing to serve communications functions, such as tracking and navigation in health care applications. The substrates of the wearable antennas will be made from textile materials and since it is wearable, it should have a small size, be light weight, low maintenance, and unobtrusive. This proposed paper will also investigate the influence of different parameters for wearable antenna including types of textile/substrate to ensure that the antenna design satisfies WBAN requirements. The characteristics and behavior of the antenna need to adhere to specifications set by wireless standards and system technology requirements. This means that the transmitting and receiving frequency bands of the various units need to be chosen accordingly. Since there are restrictions on the level of power to which the human body can be exposed to, the antenna as well as other RF system components must be designed to meet these restrictions. Antenna gain, which directly affects power transmitted, is a critical parameter in ensuring power levels fall within the safety guidelines and so will be of primary importance in the design. The electromagnetic interaction between WBAN antennas and devices and the human body will also be explored.

• Journal of IKEEE
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• v.16 no.4
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• pp.405-409
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• 2012

In this paper, on-chip antennas applicable to ultra low power wireless transceiver are designed and evaluated. Using $0.18{\mu}m$ SiGe MMIC process, 4 types of antenna with $1{\times}1mm^2$ dimensions are fabricated. The on-wafer measurement in a microwave probe station is conducted to measure the input VSWR and antenna performance of the designed on-chip antenna. Performance evaluation results show that developed antennas can be easily integrated into one-chip RF transceiver for ubiquitous applications, including WPAN and human body communications.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.759-764
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• 2012

In this paper, we propose a microwave hyperthermic lipolysis method to reduce subcutaneous fat without skin burn using external RF antenna. Since skin is closer to the antenna and has higher conductivity compared to the fat beneath, the temperature of the skin rises higher than that of the fat when the external antenna illuminates EM energy into a body, which may cause skin burn. In order to avoid the damages on skin, a skin cooling system is employed to the external antenna. The operating frequency is set at 5.8 GHz which is one of the ISM bands, to concentrate EM power efficiently on fat and not to heat up the muscle behind the fat. The operation time and RF power level has been determined based on experimental results with pork. The feasibility of the proposed method was shown by applying the method to the rat.