• Journal of the Korea Convergence Society
• /
• v.7 no.6
• /
• pp.23-28
• /
• 2016

In this study, an investigation study on EMC(Electromagnetic Compatibility) is presented for power converter circuit. A DC-DC power converter circuit using LT3652 chip is designed and fabricated. The simulation results using ANSYS SIwave for far field radiation and unwanted emissions are presented. To minimize the unwanted emissions, we design a optimized circuit by using capacitors and ground posts. The conducted and radiation emissions are measured in the EMC test chamber based on standardized testing procedures of CISPR 22. The measured EMI emission values for a power converter circuit are presented and compared with the original circuit. The results show that the unwanted emissions from the circuit are tremendously diminished due to the applied EMI reduction techniques. The results proposed here can be usefully applied on designing power converter modules.

• Current Optics and Photonics
• /
• v.7 no.2
• /
• pp.147-156
• /
• 2023

Circularly polarized (CP) emission can be achieved by integrating emissive materials into chiral metasurfaces. Such CP light sources in integrated device platforms are desirable for important potential applications. However, the exact characterization of the polarization state in CP emission may include some errors because of the unwanted polarization distortion caused by optical components (e.g., beam splitter) in the optical setup. Here, we consider CP emission measurements from chiral metasurfaces and characterize the polarization distortion caused by the beam splitter. We first detail the procedures for the Stokes parameters and Mueller matrix measurements. Then, we directly measure the Mueller matrix of the beam splitter and retrieve the original polarization state of CP emission from our metasurface sample. Using the measured Mueller matrix of the beam splitter, we specifically identify what contributes to polarization distortion in CP emission. Our work may provide useful guidelines for the characterization and compensation of polarization distortion in general Stokes parameter measurements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.10a
• /
• pp.898-899
• /
• 2013

In recent years, logistics tracking Device using to improve logistics efficiency are being extensively researched. The purpose of this paper is to Enhancement technology for unwanted emission of logistics tracking device usable cargo container security transport.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.581-584
• /
• 2005

Ion beam processing is one of the key technologies to realize mastless and resistless sub 50nm nano fabrication. Unwanted effects, however, may occur since an energetic ion can interact with a target surface in various ways. Depending on the ion energy, the interaction can be swelling, deposition, sputtering, re-deposition, implantation, damage, backscattering and nuclear reaction. Sputtering is the fundamental mechanisms in ion beam induced direct patterning. Re-deposition and backscattering are unwanted mechanisms to avoid. Therefore understanding of ion beam-solid interaction should be advanced for further ion beam related research. In this paper we simulate some important interaction mechanisms between energetic incident ions and solid surfaces and the results are compared with experimental data. The simulation results are agreed well with experimental data.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.2
• /
• pp.790-794
• /
• 2012

A output strength is limited according to the frequency used in order to protect other wireless stations from interference caused by radio waves emitted from the low power wireless installations. For receivers, unwanted spurious emission is regulated, and regulations in Korea define that additional spurious emission for receivers in the low power wireless installations under 1GHz should be -54dBm, but no regulations have been established yet for low power wireless installations over 1GHz. It is presently required to set domestic standards for devices over 1GHz on account of the expansion of the communication market and its service.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.10
• /
• pp.1802-1806
• /
• 2007

Nowadays, many configurations and applications of small atmospheric plasma source have been investigated with growing interest, as it provides the bacteria inactivation, the surface modification and removal of unwanted small regions, and so on. In this paper, the non-thermal micro plasma source under atmospheric pressure by means of submicrosecond pulse voltage waveforms is suggested. Plasma operates in helium is appears as a small (sub-mm) glow at the tip of a plasma gun. Electrical measurements show that the plasma source operates at low voltage (about 500V) and the power consumption is about 1W at 25kHz. Moreover, the emission spectrum shows the relatively higher emission intensity of oxygen particles than those of helium and nitrogen.

• Journal of Korean Vacuum Science & Technology
• /
• v.3 no.1
• /
• pp.90-94
• /
• 1999

Field Emission display (FEDs) require enhancement in both driving methods and process techniques to improve the display image quality. However, from the point of view of manufacturing, it is difficult to find methods and techniques to realize low cost manufacturing. New and simple color phosphor screen designs were suggested with non-crossed electrode lines and full color anode panels for small area displays were demonstrated. To avoid unwanted reaction with gases produced from phosphors in a high vacuum glass container, a very thin polyimide layer was coated on the phosphor screen. Moreover, to improve the display image quality, black matrix composed of inorganic materials was fabricated. This paper describes the performance and characteristics of the new full color anode panels.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.963-965
• /
• 2009

For the low power wireless installations, limited frequency resources are divided by use for their effective use and are assigned. Moreover, output strength is limited according to the frequency used in order to protect other wireless stations from interference caused by radio waves emitted from the low power wireless installations. For receivers, unwanted spurious emission is regulated, and regulations in Korea define that additional spurious emission for receivers in the low power wireless installations under 1GHz should be -54dBm, but no regulations have been established yet for low power wireless installations over 1GHz. It is presently required to set domestic standards for devices over 1GHz on account of the expansion of the communication market and its service.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1993.10a
• /
• pp.70-75
• /
• 1993

Chatter vibration is an unwanted phenomenon in metal cutting and it always affects surface finish, tool life machine life and the productivity of machining process. The In-process monitoring & control of chatter vibration is necessarily required to automation system. In this study, we constructed the multi-sensing system using Tool Dynamometer,Accelerometer and AE(Acoustic Emission) sensor for the credible detection of chatter vibration. And a new approach using a neural network to process the features of multi-sensor for the recognition of chatter vibration in turning operation is proposed. With the back propagation training process, the neural network memorize and classify the feature difference of multi-sensor signals.

• Electronics and Telecommunications Trends
• /
• v.19 no.4 s.88
• /
• pp.135-141
• /
• 2004

본 논문에서는 국내 무선설비규칙의 불요발사 규정과 관련하여 2003년도 세계전파통신회의(World Radiocommunication Conference-03)의 의제 중 하나인 불요발사에 관한 전파규칙의 내용을 소개한다. 최근 ITU-R은 WRC-03 전파규칙의 불요발사 규정에서 스퓨리어스 발사의 측정기준을 위하여 대역외영역과 스퓨리어스영역의 개념을 새롭게 정의한 후 두 영역 사이의 경계기준을 정하였다. 따라서 본 논문에서는 ITU-R의 불요발사 영역개념과 경계기준을 분석하고, 이를 바탕으로 무선설비규칙 제5조 스퓨리어스발사의 허용치에 관한 개정의견을 제시하였다.