• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.9
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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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• v.10 no.4
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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.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.1
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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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• v.8 no.1
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• pp.133-136
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• 1990

Intracavitary brachytherapy combined hypertermin for utero-conical cancer seems to be a promising method for salvage treatments in persistent tumors and inoperable or previously irradiated cervical recurrences. In order to heat the vaginal apex and uterus, powerfull conical antennas which are suitable for afterloading cervical applicator have been designed for use in conjuction with intracavitary radiation therapy. The antennas were constructed with conical conductive material to feed line and the effective lenght were designed proportional to microwave length, Power deposition profiles of 2450 MHz of conical antennas were studied in both phantom models and muscle tissue and compared to those of commonly used dipole antenna. Improvement of the heating pattern was found in both phantom and muscle tissue. The heating pattern produced by the conical antenna resembles an ellipsoid and then the temperature distribution in depth was extended to $2\~3\;cm$ from the effective antenna axis.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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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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• v.18 no.2
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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.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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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.

• Proceedings of the Korean Reliability Society Conference
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• 2004.04a
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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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• v.32 no.6
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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.