• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.5
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• pp.676-685
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• 2001

In this paper, the design method of the meander-coupled Wilkinson power divider with slit is proposed. Because the electrical performance of this structure is varied with each coupling distance and the slit's size, a tedious design work, which is done by trial and error correction, is required to determine the values of parameters for the best suitable operation. To solve this problems, therefore, an experimental design formulas for optimum performance are presented by curve fitting, under the desired center frequency($f_0$). As the example using the proposed design equation, we designed and fabricated the meander-coupled divider at $f_0$=1.5 GHz. It has better electrical performance and measured results also agrees very well that of the simulated. From these observation, it can be concluded that the obtained design formulas are useful for design of this divider.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.35-35
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• 2023

The main reason for its instability is sediment scouring downstream of hydraulic structures. Both physical and numerical models have been used to investigate the influence of soil properties on scour hole geometry. Nevertheless, no research has been conducted on resistance parameters that affect sedimentation and erosion. In addition, auxiliary structures like wing walls, which are prevalent in many real-world applications, have rarely been studied for their impact on morphology. The hydraulic characteristics of steady flow through a boxed culvert are calibrated using a 3D Computational Fluid Dynamics model compared with experimental data in this study, which shows a good agreement between water depth, velocity, and pressure profiles. Test cases showed that 0.015 m grid cells had the lowest NRMSE and MAE values. It is also possible to quantify sediment scour numerically by testing roughness/d₅₀ ratios (c_s) and diversion walls at a meander flume outlet. According to the findings, c_s = 2.5 indicates a close agreement between numerical and analytical results of maximum scour depth after the culvert; four types of wing walls influence geometrical deformation of the meander flume outlet, resulting in erosion at the concave bank and deposition at the convex bank; two short headwalls are the most appropriate solution for accounting for small changes in morphology. A numerical model can be used to estimate sediment scour at the meander exit channel of hydraulic structures based on the roughness parameter of soil material and headwall type.

• 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.

• 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.

• 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 (${\epsilon}_r=4.4$, $tna{\delta}=0.02$).

• Progress in Superconductivity
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• v.14 no.2
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• pp.102-105
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• 2012

We are developing meander-shaped metallic magnetic calorimeters using micro-fabrication methods. A planar Nb coil in a meander shape was fabricated on a Si substrate. The coil was designed to have a persistent current using a metal heater evaporated on a part of the coil. A paramagnetic sensor, $5{\mu}m$ thick Au:Er foil, was glued on top of the meander structure with epoxy. The magnetization and heat capacity were measured at different temperatures, and applied field currents matched well with expected values. The detector showed an energy resolution of 4 keV FWHM for the 5.5 MeV alpha particles.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.5 no.1
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• pp.13-21
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• 1994

A numerical analysis and experimental investigation of microstrip meander lines is given with reference to their low-pass amplitude and phase characteristics. The analysis features the inclusion of equivalent circuit models for bends to analytical equations for the muntual couplings between lines. The numerical simulation is efficient and is not constrained by the number of the coupled lines. Experimental results for 4=coupled meander lines, which are in good agreement with the simulation, are included.

• 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.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.323-328
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• 2005

The paper describes a meander antenna using magneto-dielectric composite for 433.92 MHz band. The antenna with magneto-dielectric material in this paper is suggested for miniaturization of antenna size. The return loss of meander antenna is achieved by optimizing the permittivity, $\varepsilon_r$=1.71-j0.004 and permeability, $\mu_r$=2.39+j2.58. Over all dimension of the antenna is $51\times11\times1.6mm$. The return loss and gain are -41 dB, -5dBi, respectively at 433.92 MHz.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2001.02a
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• pp.92-94
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• 2001

We investigated quench recovery characteristics of Au/YBCO thin film meander lines. YB$a_{2}$$Cu_{3}$ $O_{7}$films were coated in-situ with a gold layer and patterned into 2 mm wide meander lines by photolithography. The limiters were tested with simulated fault currents at various source voltages. Resistance decreased first slowly and then rapidly to zero. Resistance vs. time curves for different source voltages fell on top of each other when translated horizontally. The slowly varying portion of data fell on straight lines of a slope on a semi-log scale at all source voltages. A heat balance equation reflecting heat loss from meander lines to surroundings explains these results quantitatively.