• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3614-3619
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• 2022

To operate the ion cyclotron resonance heating (ICRH) antennas in a better heating state and produce relatively low impurities, it is necessary to control the antenna spectrum by changing the antenna phasing. As the electrical length of the antenna feeding transmission lines is changing as a matter of the standing wave pattern at the ceramic supports, 90° elbows, T-connectors and antenna loops, we chose to measure the current at the grounding points of the antenna loops by antenna strap probe. The voltage drops along a small, several millimeter-long paths at the end of the antenna loops give a signal that is proportional to the current in the antenna loop. Through the simulation of the antenna strap probe and the actual measurement of the antenna phasing under vacuum conditions, the reliability of the antenna strap probe based diagnostic system have been successfully proved. Moreover, this system was successfully applied to the ICRH daily experiments in the spring of 2021. In the near future, the active real-time feedback control of the antenna phasing system will be developed based on this diagnostic system in the EAST tokamak.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.105-113
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• 2009

In this paper, a vehicle antenna for AM, FM, TDMB, GPS systems was designed and implemented. AM antenna loaded into small space of shark shape was designed by ferrite turn style antenna. For the FM and TDMB antenna, folded monopole antenna which helical is folded was applied. GPS antenna for achieving characteristics both bandwidth and gain improvement was designed microstrip patch that has air substrate and fractal structure. Receiving signal strengths by the measurement were presented for the AM, FM and TDMB antenna. AM signal strength was -65.7dBm, this strength is almost as same conventional pole antenna as -63.4dBm. It can be replaced conventional pole or glass antenna by the studied antenna. Signal strengths for FM and TDMB were -55.66 and -43.50dBm at center frequency, they are 5~10dB higher than conventional antenna. Measurements of bandwidth and gain for the GPS antenna showed 135 MHz under VSWR 2 : 1 and 4.31dBi, gains over GPS band were 3~5dB higher than ceramic patch antenna.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1642-1646
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• 2011

In this paper, A Design of 2.45GHz and GPS antenna Integrated Board using Container security Device(ConTracer) for container cargo transportation is proposed and experimentally evaluate. Integrated antenna board include 2.4GHz chip and Ceramic GPS antenna is also consider the impact of RF interference based on simulation for applied to steel container. After a careful comparison and analysis a part of the container door for its best performance, We conduct tests to characterize. The proposed integrated antenna board is suitable for container cargo transportation application in steel container field.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.6
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• pp.288-294
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• 2004

In this paper, a ceramic antenna and diplexer are designed for dual-band handset ap plications. Basically, the antenna is designed by using the meander line configuration. The diplexer presented in this paper is composed of both low- and high-pass filters. We have designed the low- and high-pass filters with attenuation poles to improve the attenuation performances of the diplexer. The attenuation poles are located at each rejection frequency region so as to improve the shrinkage characteristic of the diplexer. In order to accomplish the volume effectiveness, the antenna and the diplexer have been designed and fabricated in a multi-layer structure. The diplexer designed with a multi-layer structure has inductors and capacitors, which are implemented by LTCC (Low Temperature Co-fired Ceramics) process technique. Design of the multi-layer antenna and diplexer has been achieved by employing the full 3-D EM simulation. The designed antenna and diplexer offer excellent return loss and broadband performances with highly isolated rejection performance.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.3
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• pp.215-221
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• 2009

In this paper, a slotted trapezoidal microstrip fractal patch antenna is designed and fabricated for the vehicle GPS antenna. We designed air substrate patch antenna to obtain gain improvement by the elimination of dielectric loss. By applying fractal structure with crossed slot to trapezoidal patch, we obtained 42.5 % as much patch size as conventional triangular patch antenna. Measured bandwidth was 200 MHz on GPS band under VSWR 2:1 And gain was 4.31 dBi at resonant frequency that is 2$\sim$5 dB higher gain than conventional ceramic patch antenna on GPS band.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.300-304
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• 2002

We fabricated thick film monopole antennas using Mo-doped $BiNbO_{4}$ ceramics and investigated their electrical properties as a function of the Mo-doping concentration. Compared with undoped $BiNbO_{4}$ ceramics, 10 at.% Mo-doping improved microwave dielectric properties of ceramics by increased sintered density as well as decreased space charge density. Further increase in the Mo-doping concentration caused formation of $Bi_{2}MoO_{6}$ phases, resulting in deterioration of the microwave characteristics. The gain and bandwidth of the ceramic monopole antenna were also greatly affected by the Mo-doping concentration. When Mo-doping concentration was 10 at%, highest gain of ~0.7dBi with lowest bandwidth of 30% at 2.3GHz was obtained.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.1
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• pp.55-62
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• 2000

In this paper, cellularphone antenna was designed to be capable of being mounted on the circuit-board with co-planar feeding method. The designed antenna is fabricated by the following procedure : make the multi-layered dielectric ceramic($\varepsilon_{\tau}$=23) hexahedron($7.5mm\times4.5mm\times0.4mm$) and then produce λ/4 monopole radiation element with helical structure on the surface of the hexahedron. The results are as followings : Returnloss 27.36 dB, -10 dB bandwidth 76 MHz(3.97 %), H-plane average gain -9.43 dBd.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.623-627
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• 2014

In recent years, wireless communication technologies in human body have received an increasing attention and the research on an antenna that can be worn also has been actively conducted. In this paper, an wearable antenna that can receive GPS signal frequency is proposed. The antenna was manufactured by using a copper polyester fabric with thickness of 0.08mm as a radiator and a ground plate, and a goatskin with thickness of 0.7mm as dielectric substrate. Cutting edges placed in diagonal direction of square patch in order to obtain a circular polarization characteristic, and the conductive cloth and leather was laminated by using a conductive epoxy. First, goatskin dielectric constant was obtained through the simulation and measurement of resonance frequency of the three square patch antennas with different size. On the basis of the results, an antenna operating in the GPS band was designed and the performance of the antenna was validated by making the experiment. The change of the characteristic of the antenna that is located on the shoulder parts of the clothing and wearing person were measured. And it was confirmed that the reception sensitivity has a similar level as compared to the commercially produced ceramic GPS antenna.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.211-212
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• 2008

Ceramic chip antenna with exponentially tapered ground and parasitic patch is proposed for UWB system. We obtained the return loss of average -12 dB over the range of $3.1\;{\sim}\;10.6\;GHz$ but average -7.2 dB and -7.9 dB over the range of $7.9\;{\sim}\;9.3\;GHz$ and $10.0\;{\sim}\;10.6\;GHz$ respectively. Also, we obtained the group delay of average 0.603 ㎱. The simulation results by HFSS agreed with the measured results.

• Smart Structures and Systems
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• v.16 no.3
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• pp.435-457
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• 2015

The most widely known form of multifunctional aircraft structure is smart structures for structural health monitoring (SHM). The aim is to provide automated systems whose purposes are to identify and to characterize possible damage within structures by using a network of actuators and sensors. Unfortunately, environmental and operational variability render many of the proposed damage detection methods difficult to successfully be applied. In this paper, an original robust damage detection approach using output-only vibration data is proposed. It is based on independent component analysis and matrix perturbation analysis, where an analytical threshold is proposed to get rid of statistical assumptions usually performed in damage detection approach. The effectiveness of the proposed SHM method is demonstrated numerically using finite element simulations and experimentally through a conformal load-bearing antenna structure and composite plates instrumented with piezoelectric ceramic materials.