• 한국전기전자재료학회논문지
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• 제19권9호
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• pp.832-837
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• 2006

Antennas were fabricated by physical(adhesive) and chemical(deposition+plating) method on organic-inorganic composite material. And antennas were measured dielectric constant and gain. Dielectric constant of antennas were fabricated by physical method was decreased with increase of adhesive tape thickness and number of conduction material composition. But antennas were fabricated by chemical method was reached to 90 % of dielectric material. Gain of antennas were fabricated by physical method was decreased with increase of adhesive tape thickness. But they were unrelated with conduction material composition. The other side antennas were fabricated by chemical method excelled more 0.8 dBic than antennas were fabricated by physical method in gain of antenna. Finally, chemical method can expect excellent product process because it can produce smaller size, higher gain and elimination of many handworks.

• Journal of electromagnetic engineering and science
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• 제10권4호
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• pp.224-230
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• 2010

Wireless power transmission (WPT) is useful technology in near future. There are some kinds of the WPT technologies, WPT via radio waves, resonance coupling, and inductive. Especially the WPT via radio waves is used for multi-purposes from short range to long range application. However, unfortunately it is misunderstood that it is low efficiency and low power. In this paper, I show the theory of beam efficiency between transmitting antennas and receiving antennas and also show some high efficient applications of the WPT via radio waves. Especially, I pick up a wireless power charging system of an electric vehicle and show the experimental results. I show difference between the theory of beam efficiency and the experimental results of short range WPT. I indicate that reasons of poor beam efficiency in the experiment are (1) change of impedance caused by mutual coupling between transmitting antennas and receiving antennas, (2) oblique direction of microwave power to receiving antennas caused by short distance.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권1호
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• pp.47-54
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• 2003

The radiating multislotted antennas widely used in the antennas technique are rather prospective for the application in industrial installations for microwave heating. In this paper, the model of such an antenna is experimentally investigated. The model under investigation presents a section of the waveguide Inn 340 whose broad wall contains 15 movable slotted plates. This design allows to experimentally define a location of all the slots providing the necessary distribution of radiating power along the waveguide with minimal SWR of all the system. The variants of power uniform distribution along the waveguide as well as the power decreasing to the waveguide end are examined. The application of plates with different thickness allowed to estimate the influence of the walls thickness on the Power distribution. The possibility of system extra-tuning with the help of tuning screws located in the vicinity of each slot is considered. Obtained results are compared to the conducted theoretical calculations and data in references.

• Radiation Oncology Journal
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• 제8권1호
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• pp.133-136
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• 1990

자궁암치료에서 재발되거나 치료가 어려운 종양에 대하여 방사선과 온열요법을 병행함으로서 치료 성과를 다소 향상시킬 수 있었다. 더욱이 방사선 근접조사와 강내온열치료는 주위 건강조직의 피해를 줄이면서 종양에 집중손상을 줄 수 있었으며 강내방사선조사 기구를 공동으로 이용하므로서 시술이 간단하고 치료부위를 정확히 조준할 수 있었다. 그러나 강내조사용 안테나는 그 모양과 구성에 따라 온열 분포가 변하며 재래식 쌍극철심형 안테나는 끝부분 또는 연결부위의 가온이 급증하여 균등한 온열분포를 기대할 수 없었다. 저자들은 안테나의 길이를 마이크로파의 약수 즉 3, 6, 12 cm로 하여 공명이 잘 이루어지도록 하였으며 끝이 굵고 접촉 부위가 가느다란 꼬깔형 (conical) 안테나를 제작하여 사용한 결과 안테나 축에 따라 거의 일정하거나 약간 타원형의 온도분포를 이루었으며 가온 깊이도 $2\~3\;cm$로서 비교적 깊은 곳까지 가열할 수 있어 강내 치료효과를 향상시킬 수 있다고 생각된다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.43-46
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• 2003

This paper presents capacity characteristics of the indoor LOS(Line-Of-Sight) propagation channel for MIMO system at 5GHz. The distance between antenna elements, their moving path, and number of transmitting and receiving antennas can be determined by wanted eigen-vlaue, and channel capacity of the MIMO communication channel using only reliable simulation without measurements. The simulation uses 3D Ray tracing and patch scattering model to which electromagnetic material constants are applied. As distance between antenna elements increases, distribution of the eigen-value show a tendency to decrease, but channel capacity increases in LOS environment. However, despite of short distance between antenna elements, large value of channel capacity is obtained in positions which have high AS. When the position of receiver antennas are shifted, channel capacity hardly changed, and as number of antenna elements increases, channel capacity also increases regularly.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.389-392
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• 1996

The recent development of high temperature superconducting epitaxial thin film offer great potential for planar passive microwave application such as ring resonator, filters, transmission lines, and antennas. This paper describes the fundamental properties of Microstrip Band-Pass Filter using HTS Thin Film and its application to microwave devices. In order to fabricate HTS microstrip multiple filters, We have grown laser ablated HTS thin films, patterned by photolithographic process and wet etching processes intro HTS microwave devices.

• Journal of Magnetics
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• 제18권2호
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• pp.178-182
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• 2013

We have developed a new non-conventional electron paramagnetic resonance (EPR) spectrometer, in which no resonant cavity was used. We previously demonstrated a wide frequency range operation of an EPR spectrometer using two loop antennas, one for a microwave transmission and the other for signal detection [1]. In contrast to Ref. [1], the utilization of a microstrip antenna as a transmitter enhanced a capability of wide-band operation. The replacement of conventional capacitors with varactor diodes makes resonance condition easily reproducible without any mechanical action during tuning and matching procedure since the capacitance of the diodes is controlled electronically. The operation of the new EPR spectrometer was tested by measuring a signal of 1,1-diphenil-2-picrylhydrazyl (DPPH) sample in the frequency range of 0.8-2.5 GHz.

• 한국생산제조학회지
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• 제21권1호
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• pp.156-160
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• 2012

Recently WCDMA signal transmission technology by large output microwave antenna have showed reduction of human resources and operating expense. But the existing antenna brackets cost is very expensive also its structure and functions are complicated. Unit brackets, suspending some sensors, subjected to acceleration loads, often fail due to self-vibration. To prevent such failures, it is necessary to understand the fatigue failure mode and to evaluate the fatigue life using tests or analysis techniques. The objective of this study is to develop the component test specifications, which are applicable to predict fatigue life at initial product design step, for unit brackets using vibration fatigue technique. So its application is limited to installation and management. In this project, we studied about more convenient bracket for microwave antennas through improvement on the existing antenna bracket's shortcoming and could develop an improved universal antenna bracket system for simple installation and application.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2004년도 신뢰성해외전문가초청세미나
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• pp.41-51
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• 2004

Contractual agreement. Established on sale of product. Establishes. Buyer responsibility. Limitations. Seller liability.(omitted)

• ETRI Journal
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• 제32권6호
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• pp.901-910
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• 2010

As a supplement to X-ray mammography, microwave imaging is a new and promising technique for breast cancer detection. Through solving the nonlinear inverse scattering problem, microwave tomography (MT) creates images from measured signals using antennas. In this paper, we describe a developed MT system and an iterative Gauss-Newton algorithm. At each iteration, this algorithm determines the updated values by solving the set of normal equations using Tikhonov regularization. Some examples of successful image reconstruction are presented.