• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1201-1202
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• 2008

In this paper, using symmetrical condensed node(SCN), the TLM numerical technique has been successfully applied to microstrip meander line. A detailed technique of the symmetrical condensed node(SCN) may be used to model planar microstrip transmission line is presented. Also, the S-parameters $S_{11}$ and $S_{21}$ of microstrip meander line have been computed. From obtained results, TLM analysis is shown to be an efficient method for modeling complicated structure of planar microstrip transmission line.

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.270-273
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• 2008

A small meander line antenna for T-DMB (Terrestrial Digital Multimedia Broadcasting) is presented. The antenna proposed here is based on a typical planar meander line antenna and miniaturized by using a double sided structure. A prototype antenna is manufactured based on the simulation results and the basic performances are measured. The presented antenna designed to operate in T-DMB band (174~216MHz) and can be adopted for various mobile applications.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2293-2298
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• 2011

In this paper, A tag antenna structure for RFID application with resonant frequency of 920MHz is proposed using the meander line technique and Evolution Strategy. Miniaturization structure design for a tag antenna is performed by structure combining the half-wave dipole with a meander line. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is made for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The optimized tag antenna size is 63mm ${\times}$ 15mm ${\times}$ 1mm. And the proposed antenna is realized on FR-4 substrate (${\epsilon}_r=4.4$, $tna{\delta}=0.02$).

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.506-510
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• 2003

In this paper, a meander-line chip antenna with stacked layer is suggested, designed and fabricated employing the LTCC(Low Temperature Co-fired Ceramic) fabrication techniques. To reduce the antenna chip size, the meander-line antenna strip is distributed over three layer. Layers one interconnected using via holes. A 2.4 GHz chip antenna with size of $3.75{\times}7.9{\times}1.0 mm^3$ is designed and fabricated using the LTCC technique. Measurements of the fabricated antenna show 160 MHz bandwidth and 3.75 dBi maximum gain. The Measured reflection coefficient and radiation patterns agree well with the prediction by electromagnetic simulation.

• Progress in Superconductivity
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• v.3 no.2
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• pp.183-187
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• 2002

In this paper we analyzed the electromagnetic behavior of high $-T_{c}$ superconductor under the quench state using finite element method. Poisson equation was used in finite element analysis as a governing equation and was solved using algebra equation using Gallerkin method. We first investigate d the electromagnetic behavior of U-type superconductor. Finally we applied our analysis techniques to 5.5 kVA meander-line superconducting fault current limiters (SFCL) which are currently developed by many power-system researcher in the world. Meshes of 14,600 elements were used in analysis of this SFCL. Analysis results show that the distribution of current density was concentrated to inner curvature in meander-line type-superconductors and maximum current density 14.61 $A/\m^2$ and also maximum Joule heat was 6,420 W/㎥. We concluded that this meander line-type SFCL was not pertinet fur uniform electromagnetic field distribution.n.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.197-202
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• 2005

In this paper, we analyzed the signal distortion incorporating meander-shaped transmission line on PCB in broadband frequency range, up to 50GHz. This broadband characteristic provides reasonable analysis of digital pulse having very short rising time. Simulation results reveal suppression characteristic at multiband which is dependent on only the width of meander arm. This width of arm also can be adjusted using different permittivity because it provides different effective wave-length. It is found that the suppression characteristic shows sharpness with as a function of the number of arms. However, these characteristics shown limitation for microstrip line structure rather than for stripline structure, so we can avoid these unwanted phenomena using stripline structure.

• Progress in Superconductivity
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• v.8 no.1
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• pp.81-86
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• 2006

We investigated resistance development in $Au/YBa_2Cu_3O_7(YBCO)$ thin film meander lines during high-power faults. The meander lines were fabricated by patterning 300 nm thick YBCO films coated with 200 nm thick gold layers into meander lines. A gold film grown on the back side of the substrate was also patterned into a meander line. The front meander line was connected to a high-power fault-test circuit and the back line to a DC power supply. Resistance of both lines was measured during the fault. They were immersed in liquid nitrogen during the experiment. Behavior of the resistance development prior to quench completion could be understood better by comparing resistance of the front meander lines with that of the back. Quench completion point could be determined clearly. Resistance and temperature at the quench completion point were not affected by applied field strength. The experimental results were analyzed quantitatively with the concept of heat transfer within the meander lines/substrate and to the surrounding liquid nitrogen. In analysis, the fault period was divided into three regions: flux-flow region, region prior to quench completion, and region after quench completion. Resistance was calculated for each region, reflecting the observation for quench completion. The calculated resistance in three regions was joined seamlessly and agreed well with data.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.221-224
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• 2002

Superconducting electrical devices are under development in a national project in Korea. And KEPCO and LGIS are in charge of development of a resistive type fault current limiters(FCLs) with YBCO thin films. In order to realize FCLs, the rated power of FCLs must be increased. For this purpose, it is of great interest to increase of allowed voltage of unit component without electrical and thermal damages. So, meander lines were widely used for the conducting path to increase maximum electric field. In this research, numerical simulations on the electromagnetic behaviors of the device were carried out, especially focusing on the effect of meander line structures on the YBCO thin films. To evaluate the structures of meander lines, three types of meander lines were considered for numerical analysis using finite element method (FEM). In this simulation, both normal state and fault conditions were considered for calculation of electric field, current density, magnetic field density. And the simulation resulted are compared to find the optimum design of meander lines for resistive FCLs.

• ETRI Journal
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• v.28 no.3
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• pp.383-385
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• 2006

A new meander-line antenna consisting of two open-ended strips is proposed for a compact and broadband UHF radio frequency identification tag. An equivalent circuit model for the proposed antenna is derived and used to perform a simple and wideband impedance match to an arbitrary complex impedance of a tag chip without any additional matching network. The performance of the proposed antenna is validated by comparing calculated and measured results, which show good agreement.

• Journal of electromagnetic engineering and science
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• v.18 no.1
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• pp.7-12
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• 2018

This article proposes an ultrahigh frequency band radio frequency identification (RFID) tag antenna for drug runout management that can be used in hospitals. The RFID tag antenna is designed to function as a sensor that alerts drug runout when a drug inside a drip chamber is completely consumed but does not work when a drug remains inside a drop chamber. A previously proposed 915 MHz dipole antenna, is too large to be attached to the drip chamber of a feeding bag. Moreover, the length of the dipole (L) should be increased for conjugate matching with an RFID chip. Therefore, the dipole antenna is downsized so that it can be attached to the drip chamber through a fine meander line structure coupling with a corrugate meander line. A transparent cover is added to enhance the grip force between the designed antenna and the drip chamber and to enable detachment. The dimensions of the completed antenna structure attachable to a drip chamber are 32.59 mm (height) and 13.5 mm (width). The gain reduction due to the decreased antenna length is enhanced. The fabricated antenna shows an average omni-directional read range of 10.65 m on a horizontal plane and has the function of sensing the presence of a drug.