• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.190-192
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• 2008

This paper shows the formulation of fast moving least square reproducing kernel method (FMLSRKM) which is a kind of meshfree methods. FMLSRKM has some advantages compared to conventional numerical techniques such as finite element method. For simple analysis on a rectangular waveguide, point collocation scheme is introduced and applied.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.119-122
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• 1989

An intermodal switch based on optically-induced (through optical Kerr effect) periodic coupling in a two-mode waveguide is described and demonstrated. A high power pump beam injected into the two modes of the waveguide produced a periodic modulation of the refractive index profile with a period of modal beat length. this causes an intermodal coupling of the prove beam. The operating principle was successfully demonstrated in an elliptical core two-mode fiber with a counter-propagating pump-probe scheme.

• ETRI Journal
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• v.27 no.5
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• pp.484-490
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• 2005

We fabricated 40 Gb/s front-end optical receivers using spot-size converter integrated waveguide photodiodes (SSC-WGPDs). The fabricated SSC-WGPD chips showed a high responsivity of approximately 0.8 A/W and a 3 dB bandwidth of approximately 40 GHz. A selective wet-etching method was first adopted to realize the required width and depth of a tapered waveguide. Two types of electrical pre-amplifier chips were used in our study. One has higher gain and the other has a broader bandwidth. The 3 dB bandwidths of the higher gain and broader bandwidth modules were about 32 and 42 GHz, respectively. Clear 40 Gb/s non-return-to-zero (NRZ) eye diagrams showed good system applicability of these modules.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.139-142
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• 2004

X-band Waveguide slot way antenna is developed for heliborne MTD radar applications. The antenna is composed of multi-layer waveguide structures. Each of them has it's own functions, such as, radiation, power/phase distribution, coupling, etc. Broad-wall offset slots are used for radiators, inclined slots on broad-wall for power distribution to radiating(branch) waveguide, some kind of coaxial probe structures for in-phase coupling and H-plane T-junction power dividers. Antenna is realized by precision machining and careful assembly. It is tested and measured by 3m${\times}$l.7m planar near-field probe, which is set-up in MTG. Far-field calculations have good agreement in tolerable bounds. Special but necessary process such as brazing, will increase the accuracy and performance. Results show promising possibilities of future applications for real systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.199-203
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• 2012

This paper introduces a simple new procedure approach to determine the permittivity of dielectric slabs. The method uses a parallel plate waveguide which supports a TEM mode. The presence of the dielectric slab placed at the bottom of the waveguide makes the speed of the TEM wave slower. The relationship between the change of the speed and the permittivity of the dielectric slab allows the determination of the permittivity. The relationship is analyzed electromagnetically, and the results of measurements are in good agreement with the analysis.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1463-1471
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• 2017

In order to monitor the pipe thinning caused by flow-accelerated corrosion (FAC) that occurs in coolant piping systems, a shear horizontal ultrasonic pitch-catch waveguide technique was developed for accurate pipe wall thickness monitoring. A clamping device for dry coupling contact between the end of the waveguide and pipe surface was designed and fabricated. A computer program for multi-channel on-line monitoring of the pipe thickness at high temperature was also developed. Both a four-channel buffer rod pulse-echo type and a shear horizontal ultrasonic waveguide type for high-temperature thickness monitoring system were successfully installed to the test section of the FAC proof test facility. The overall measurement error can be estimated as ${\pm}10{\mu}m$ during a cycle from room temperature to $200^{\circ}C$.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.455-457
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• 2006

The mutual relations and equivalence between the boundary conditions for electromagnetic waves are discussed in terms of a waveguide step. In order to verify our approach, the reflection characteristics of a rectangular waveguide step are compared with respect to the boundary conditions. The characteristics of a rectangular waveguide step are analyzed with a mode-matching technique. In order to verify our approach, convergence behaviors and electromagnetic distributions are shown.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.391-394
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• 2003

Laser direct writing process is developed 3rd harmonic Diode Pumped Solid State Laser with the near visible wavelength of 355 m sensitive polymer is irradiated by UV laser and developed using polymer solvent to obtain quasi-3D. It is important to reduce line width for image mode waveguides, so some investigations will be carried out in various conditions of process parameters such as laser power, writing speed, laser focus and optical properties of polymer. This process could be to fabricate a single mode waveguide without expensive mask projection method. Experimentally, the patterns of trapezoidal shape were manufactured into dimension of 8.4 mm width and 7.5 mm height. Propagation loss of straight waveguide measured 3 dB/cm at 1,550 nm.

• Korean Journal of Optics and Photonics
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• v.7 no.3
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• pp.272-279
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• 1996

A simple transfer matrix algorithm to analyze the properties of 2 dimensional waveguides is introduced. We applied this algorithm to strained InGaAs/InGaAsP GINSCH MQW laser structures. We studied how optical confinement factor and effective refractive index, which are important in calculating the modal gain, depend on the structure parameters such as waveguide width, shape of GRIN, and number of quantum wells. Especially we suggested that the concept of effective waveguide width is very useful in understanding the GRINSCH waveguide.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.7
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• pp.698-705
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• 2004

In this paper, we present the analysis method for a rectangular waveguide with horizontal conducting post using mode matching method and generalized scattering method. Scattering characteristics of a rectangular waveguide with the horizontal conducting post according to radius and height of the post are simulated by the proposed method. The simulated results by proposed method show good agreement with the measured results and the HFSS's results. Proposed method are easily applied to the design of a waveguide component with horizontal conducting posts.