• Title/Summary/Keyword: 3dB

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The study of the packaging for Ti:LiN$bO_3$optical modulator device and its electrical and optical characteristics (Ti:LiN$bO_3$ 광변조기 소자의 패키징 및 전기.광학적 특성)

  • 윤형도;김성구;이한영;윤대원
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.6
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    • pp.72-78
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    • 1998
  • An optical modulator Ti:LiNbO$_3$optical waveguide and CPW electrode structure were fabricated. The optical modulator was packaged using components such as ferrules, dirmy LN block and glass, vibration and shock absorbption pad, and alumina feeder through processings of pigtailing. Au wire bonding, epoxing, SMA connecting, sealing. The electrical and optical characteristics were measured after packaging. The electrical properties of S$_{21}$ and S$_{11}$ were obtained as 9.8 GHz at -3 dB and -8.9dB at 14.4GHz, respectively. Optical waveguide prepared met requirements for a single mode at a 1550nm wavelength range. Insertion loss was 4.3dB at room temperature after packaging, and was varied 4.3~6.4dB at various temperatures, 5~45$^{\circ}C$. E-O bandwidth measurement showed 3dB optical response at 7.8GHz, which means that it is applicable for 10Gbps optical communicationon

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2D to 3D Anaglyph Image Conversion using Quadratic & Cubic Bézier Curve in HTML5 (HTML5에서 Quadratic & Cubic Bézier 곡선을 이용한 2D to 3D 입체 이미지 변환)

  • Park, Young Soo
    • Journal of Digital Convergence
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    • v.12 no.12
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    • pp.553-560
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    • 2014
  • In this paper, we propose a method to convert 2D image to 3D anaglyph using quadratic & cubic B$\acute{e}$zier Curves in HTML5. In order to convert 2D image to 3D anaglyph image, we filter the original image to extract the RGB color values and create two images for the left and right eyes. Users are to set up the depth values of the image through the control point using the quadratic and cubic B$\acute{e}$zier curves. We have processed the depth values of 2D image based on this control point to create the 3D image conversion reflecting the value of the control point which the users select. All of this work has been designed and implemented in Web environment in HTML5. So we have made it for anyone who wants to create their 3D images and it is very easy and convenient to use.

Planar Type n-Way Power Divider using 2 Section (2구간을 사용한 평면형 n-방향 전력분배기)

  • 김경환;조영송;황충선;신철재
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.6 no.1
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    • pp.28-36
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    • 1995
  • In this paper, a design method of multiple n-way low loss power divider for x-band is propossed. To decrease loss, only two-stages of transmission lines are used with isolation resistors for match. Ex- perimental results for 3-way and 4-way power dividers have the divided power of 5.54~6.17dB and 6.76~7.37 dB, the return loss of more than 17dB and 12dB, and the isolation of more than 18dB and 10dB at center frequency, respectively, The measured results show good agreement with the theoretical analysis.

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Synthetic Studies on Carbapenam Skeletons

  • 구양모;서민효;이윤영
    • Bulletin of the Korean Chemical Society
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    • v.17 no.10
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    • pp.909-918
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    • 1996
  • Syntheses of carbapenam skeletons were achieved from 1,3-propanediol through 1,3-dipolar cycloaddition. 3-(Tetrahydropyran-2-yloxy)-(10) and 3-(t-butyldimethylsilyloxy) propanal (13) were obtained from 1,3-propanediol. 3-Hydroxypropanals (10, 13, 14) were reacted with N-hydroxyglycine esters to give C-(2-hydroxyethyl)-N-alkoxycarbonylmethylnitrones (15a-15d). 1,3-Dipolar cycloaddition of the nitrones with methyl acrylate or ethyl crotonate gave 3-(2-hydroxyethyl)isoxazolidines (16a-16b, 17a-17b, 18, 19a-19b). 3-(2-Hydroxyethyl)isoxazolidines (17a, 17c, 19a, 19b) were converted to 3-(2-iodoethyl)isoxazolidines (21a-21d) or 3-phenylthiocarbonylmethylisoxazolidines (25a-25d) which were cyclized to give 2-oxa-1-azabicyclo[3.3.0]octanedicarboxylates (22a-22d, 26a-26d). 2-Oxa-1-azabicyclo[3.3.0]octane-4,8-dicarboxylates (22c-22d, 26c-26d) were transformed to 6-(l-hydroxyethyl)carbapenam-3-carboxylates (30a-30b, 31a-31b).

Chemical Structures and Physiological Activities of Plant Growth Substance, Malformin B's (식물생장조절물질 말포민 B동족체의 화학구조 및 생리활성)

  • Kim, K.W.
    • Korean Journal of Weed Science
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    • v.15 no.1
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    • pp.85-98
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    • 1995
  • Six malformin B's produced by Aspergillus niger van Tiegh. were separated by HPLC. Their structures determined by the methods of amino acid analyses, mass spectrometry, and two-dimensional NMR were revealed as cyclic pentapeptides structurally related to malformin $A_1$. Both the NMR and MS/MS data suggest that the respective structures of separated malformin B's were as follows; cyclo-D-Cys-D-Cys-L-Val-D-Leu-L-allo-Ile for $B_{1a}$, cyclo-D-Cys-D-Cys-L-Val-D-Leu-L-Leu for $B_{1b}$, cyclo-D-Cys-D-Cys-L-Val-D-Val-L-Leu for $B_2$, cyclo-D-Cys-D-Cys-L-Val-D-Ile-L-Leu for $B_3$, cyclo-D-Cys-D-Cys-L-Val-D-Ile-L-Ile for $B_4$, and cyclo-D-Cys-D-Cys-L-Val-D-Val-L-Ile for $B_5$. Among the malformin B's, the structure of $B_{1b}$ was the same as that of malformin $A_3$ or C. All the malformin B's showed physiological activities in the two assay systems using corn(Zea mays L.) roots and mung bean(Phaseolus aureus Roxb.) hypercotyl segments. The malformin B's with molecular weight 529 were more effective for inducing corn root curvature than those with molecular weight 515. The difference in molecular weight of malformin B's, i.e., the retention time on HPLC, results in the polarity change of the whole malformin molecule which affects the revealation of the malformin activities. In addition, the disulfide form of the malformin B's gives the rigidity of the molecule, whereas the combination of the fourth and the fifth amino acid residues provides the optimal three-dimensional configuration to the malformin receptor of plants. Presumably, these two factors are appeared to be essential for the greatest physiological activity of malformin B's. malformin $B_{1a}$ caused the corn root curvature by 90% at a concentration of $0.25{\mu}M$. However, such differential activities with molecular weight of 529 or 515 of malformin B's were not found in the mung bean hypercotyl segment test. Maximum stimulation of mung bean hypercotyl growth was observed at $0.1{\mu}M$ concentration of malformin B's. The growth of the segments treated with $B_5$ was 154% greater than that of the control.

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Improvement of Radiation Performance of Mobile Phone Antenna Using PIFA on U-Shaped Ground Plane (U-형 접지면 상에 배치된 평판형 역 F 안테나 구조를 이용한 휴대폰 단말기의 무선 성능 개선)

  • Lee, Jeong-Ho;Song, Jae-Kwan;Yook, Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.1
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    • pp.90-97
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    • 2010
  • In this paper, we propose antenna topology and ground plane shape to improve the performance of PIFA (Planar Inverted F Antenna) which is built-in mobile phone. First, we designed the PIFA antenna consists of multiple radiators to provide multi-current paths. Then we designed U-shaped ground plane on the PCB under the antenna. The proposed antenna structure shows TRP/TIS improvement of 2.0 dB/3.7 dB for GSM and 2.2 dB/ 2.0 dB for DCS and 0.8 dB/1.5 dB for PCS and 1.3 dB/0.7 dB for WCDMA at the free space.

Single-Balanced Low IF Resistive FET Mixer for the DBF Receiver

  • Ko Jee-Won;Min Kyeong-Sik
    • Journal of electromagnetic engineering and science
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    • v.4 no.4
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    • pp.143-149
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    • 2004
  • This paper describes characteristics of the single-balanced low IF resistive FET mixer for the digital beam forming(DBF) receiver. This DBF receiver based on the direct conversion method is designed with Low IF I and Q channel. A radio frequency(RF), a local oscillator(LO) and an intermediate frequency(IF) considered in this research are 1950 MHz, 1940 MHz and 10 MHz, respectively. Super low noise HJ FET of NE3210S01 is considered in design. The measured results of the proposed mixer are observed IF output power of -22.8 dBm without spurious signal at 10 MHz, conversion loss of -12.8 dB, isolation characteristics of -20 dB below, 1 dB gain compression point(PldB) of -3.9 dBm, input third order intercept point(IIP3) of 20 dBm, output third order intercept point(OIP3) of 4 dBm and dynamic range of 30 dBm. The proposed mixer has 1.0 dB higher IIP3 than previously published single-balanced resistive and GaAs FET mixers, and has 3.0 dB higher IIP3 and 4.3 dB higher PldB than CMOS mixers. This mixer was fabricated on 0.7874 mm thick microstrip $substrate(\varepsilon_r=2.5)$ and the total size is $123.1\;mm\times107.6\;mm$.

The Design and implementation of a 5.8GHz band LNA MMIC for Dedicated Short Range Communication (단거리전용통신을 위한 5.8GHz대역 LNA MMIC 설계 및 구현)

  • 문태정;황성범;김용규;송정근;홍창희
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.8
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    • pp.549-554
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    • 2003
  • In this paper, we have designed and implemented by a monolithic microwave integrated circuit(MMIC) of a 5.8GHz-band low noise amplifier (LNA) composed of receiver front-end(RFE) in a on-board equipment system for dedicated short range communication. The designed LNA is provided with two active devices, matching circuits, and two drain bias circuits. Operating at a single supply of 3V and a consumption current of 18mA, The gain at center frequency 5.8GHz is 13.4dB, NF is 1.94dB, Input IP3 is -3dBm, S$_{11}$ is -18dB, and S$_{22}$ is -13.3dB. The circuit size is 1.2 $\times$ 0.7 $\textrm{mm}^2$.>.

Directivity Gain Improvement Method for UWB Coplanar Patch Antenna (UWB 평면 패치안테나의 지향성이득의 향상 방법)

  • Joo, Chang-Bok
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.6
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    • pp.63-70
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    • 2012
  • This paper discussed on the directive gain improvement method of the U-type ultra wide-band(UWB) planar patch antenna model with CPW feeding. For directive gain improvement, the U-type printed patch antenna model with CPW feeding is reconstructed as a microstrip structure by adding a reflection plane with aperture slot. The reflection coefficient of the reconstructed antenna is less than -6.5 dB(VSWR < 3.3) to the characteristic impedance of $50.08{\Omega}$ and showed the directive radiation patterns with the directive gain of 7.5 dBi ~ 10.1 dBi, the front-back ratio of 17.8 dB ~ 28.7 dB and the range of -3dB radiation angle over ${\pm}30^{\circ}$ to the main beam direction of ${\theta}=0^{\circ}$.

Design of a Waveguide 8×8 Butler Matrix for Ka-Band Broadband Multi-Port Amplifiers(MPAs) (Ka 대역 광대역 다중 단자 증폭기를 위한 도파관 8×8 버틀러 매트릭스 설계)

  • Lee, Hong-Yeal;Uhm, Man-Seok;Yom, In-Bok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.4
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    • pp.449-456
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    • 2012
  • Herein, we design a wideband $8{\times}8$ waveguide Butler matrix in order to use in a multi-port amplifiers(MPAs) at Ka-band. To achieve the broadband characteristic, we design a binomial 6-slot 3 dB directional coupler which is used to configure the $8{\times}8$ Butler matrix. The measured results of the fabricated $8{\times}8$ Butler matrix have low insertion loss of less than 0.3 dB, good return loss of over 26 dB and high isolation of over 35 dB within the design bandwidth of 3 GHz.