• Title/Summary/Keyword: electromagnetic device

Search Result 509, Processing Time 0.038 seconds

LOW NOISE AMPLIFIER USING ELECTROMAGNETIC SIMULATOR AT U-NII FREQUENCY BAND

  • Kim, Hak-Sung;Kim, Cheol-Su;Kim, Cheol-Su;Lee, Byung-Jae;Lee, Jong-Chul;Kim, Nam-Young
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
    • /
    • 2000.11a
    • /
    • pp.225-228
    • /
    • 2000
  • In this paper, the design for a low noise amplifier with the EM simulation is presented. The ATF36077 pHEMT device is applied to design LNA for U-NII frequency band (5 GHz ~ 6 GHz). The matching networks have been designed by the only open ended stub in order to reduce parasitic effects generated from a via structure. Through EM simulator, the simulation result shows that the linear gain (@5.5 GHz) is over 10 dB, input return loss and output return loss (@ 5.5 GHz) are a below 10 dB respectively, and the 3rd order intercept point is about 17 dBm.

  • PDF

Analysis of Hematoporphyrin Derivative by Design and Manufacture of High Resolution Charge Coupled Device in Spectrometry (분광기에 고 분해능 Charge Coupled Device의 설계 및 제작에 의한 Hematoporphyrin Derivative의 분석)

  • Kim, Ki-Jun
    • Journal of the Korean Applied Science and Technology
    • /
    • v.22 no.1
    • /
    • pp.77-83
    • /
    • 2005
  • The influence of fluorescence, scattering, and absorbance in turbid material by light scattering was interpreted by the scattered fluorescence intensity and wavelength. The effect of optical property in scattering media was investigated. It is very important to study the charge coupled device(CCD) in spectrometry because we can use the molecular energy level, molecular structure, absorption or emission, intermolecular reaction, weakly bound molecular energy, photochemistry, fluorescence and photodynamic therapy. CCD is very essential to study the molecular structure and medical engineering combined laser spectroscopy in the modem physical and chemistry. Accordingly, this study has designed and manufactured the electromagnetic spectrometry with CCD, and has analyzed the hematoporphyrin derivative.

Graphene Transistor Modeling Using MOS Model (MOS 모델을 이용한 그래핀 트랜지스터 모델링)

  • Lim, Eun-Jae;Kim, Hyeongkeun;Yang, Woo Seok;Yoo, Chan-Sei
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.26 no.9
    • /
    • pp.837-840
    • /
    • 2015
  • Graphene is a single layer of carbon material which shows very high electron mobility, so many kinds of research on the devices using graphene layer have been performed so far. Graphene material is adequate for high frequency and fast operation devices due to its higher mobility. In this research, the actual graphene layer is evaluated using RT-CVD method which can be available for mass production. The mobility of $7,800cm^2/Vs$ was extracted, that is more than 7 times of that in silicon substrate. The graphene transistor model having no band gap is evaluated using both of pMOS and nMOS based on the measured mobility values. And then the response of graphene transistor model regarding to gate length and width is examined.

MMIC Low Noise Amplifier Design for Millimeter-wave Application (밀리미터파 응용을 위한 MMIC 저잡음 증폭기 설계)

  • 장병준;염인복;이성팔
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.12 no.7
    • /
    • pp.1191-1198
    • /
    • 2001
  • MMIC low noise amplifiers for millimeter-wave application using 0.15 $\mu$m pHEMT have been presented in this paper. The design emphasis is on active device model and EM simulation. The deficiency of conventional device models is identified. A distributed device model has been adapted to circumvent the scaling problems and, thus, to predict small signal and noise parameters accurately. Two single-ended low noise amplifier are designed using distributed active device model for Q-band(40 ∼ 44 GHz) and V-band(58 ∼65 GHz) application. The Q-band amplifier achieved a average noise figure of 2.2 dB with 18.3 dB average gain. The V-band amplifier achieved a average noise figure of 2.9 dB with 14.7 dB average gain. The design technique and model employed provides good agreement between measured and predicted results. Compared with the published data, this work also represents state-of-the-art performance in terms of gain and noise figure.

  • PDF

Shielding Effectiveness of Electromagnetic Interference in ABS/Nickel Coated Carbon Fiber and Epoxy/Cu-Ni Fabric Nano Carbon Black Composites (ABS/Nickel 코팅 탄소섬유와 Epoxy/Copper-Nickel 직조 섬유 복합재료의 전자파차폐 효과)

  • Han, Gil-Young;Jung, Woo-Chul;Yang, In-Young;Sun, Hyang-Sun
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.11 no.6
    • /
    • pp.169-174
    • /
    • 2012
  • Electromagnetic interference(EMI) shielding effectiveness(SE) was investigated in of woven fabric made of epoxy/copper-nickel fabrics and nickel coated carbon fiber reinforced acrylonitrile-butadiene-styrene(ABS) composites. The coaxial transmission line method was used to measure the EMI shielding effectiveness of the composites. We designed and constructed a measuring system, consisting of a network analyzer and a device that plays the serves as a sample holder and at the same time as a transmission medium of the incident electromagnetic wave. The measurement of SE were carried out frequency range from 100MHz to 2GHz. It is observed that the SE of the composits is the frequency dependent increase with the increase in nickel coated carbon fibre volume fraction. The nickel coating with 20wt% ABS composite was shown to exhibit up to 60dB of SE. The result that nickel coated carbon fibre ABS composite can be used for the purpose of EMI shielding as well as for some microwave applications.

A Design of 5.8 ㎓ Oscillator using the Novel Defected Ground Structure

  • Joung, Myoung-Sub;Park, Jun-Seok;Lim, Jae-Bong;Cho, Hong-Goo
    • Journal of electromagnetic engineering and science
    • /
    • v.3 no.2
    • /
    • pp.118-125
    • /
    • 2003
  • This paper presents a 5.8-㎓ oscillator that uses a novel defected ground structure(DGS), which is etched on the metallic ground plane. As the suggested defected ground structure is the structure for mounting an active device, it is the roles of a feedback loop inducing a negative resistance as well as a frequency-selective circuit. Applying the feedback loop between the drain and the gate of a FET device produces precise phase conversion in the feedback loop. The equivalent circuit parameters of the DGS are extracted by using a three-dimensional EM simulation ,md simple circuit analysis method. In order to demonstrate a new DGS oscillator, we designed the oscillator at 5.8-㎓. The experimental results show 4.17 ㏈m output power with over 22 % dc-to-RF power efficiency and - 85.8 ㏈c/Hz phase noise at 100 KHz offset from the fundamental carrier at 5.81 ㎓.

A Dual Band Directional Coupler with Feedback Compensation Using Diplexer Structure (Diplexer 구조를 이용한 Dual Band 방향성 커플러)

  • Kim Ki-Joong;Park Ja-Young;Jeong Young-Hak;Bae Hyo-Gun;Kim Nam-Heung;Kim Hak-Sun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.16 no.8 s.99
    • /
    • pp.783-789
    • /
    • 2005
  • In this paper, a novel design and implementation of a dual-band directional coupler based on RF IPD(Integrated Passive Device)-on-glass technology is proposed, which can be adopted in GSM/GPRS cellular phones for closed loop power control at the output of the power amplifier. The proposed coupler has a compensation capacitor to improve the directivity, and was designed using a new diplexing structure to minimize the cross-band isolation.

Effects of 60-Hz Time-Varying Electric Fields on DNA Damage and Cell Viability Support Negligible Genotoxicity of the Electric Fields

  • Yoon, Yeo Jun;Li, Gen;Kim, Gyoo Cheon;Lee, Hae June;Song, Kiwon
    • Journal of electromagnetic engineering and science
    • /
    • v.15 no.3
    • /
    • pp.134-141
    • /
    • 2015
  • The effect of a 60 Hz time-varying electric field was studied using a facing-electrode device (FED) and a coplanar-electrode device (CED) for further investigation of the genotoxicity of 60 Hz time-varying magnetic field (MF) from preceding research. Neither a single 30-minute exposure to the CED or to the FED had any obvious biological effects such as DNA double strand break (DSB) and apoptosis in cancerous SCC25, and HeLa cells, normal primary fibroblast IMR90 cells, while exposures of 60 Hz time-varying MF led to DNA damage with induced electric fields much smaller than those used in this experiment. Nor did repetitive exposures of three days or a continuous exposure of up to 144 hours with the CED induce any DNA damage or apoptosis in either HeLa or IMR90 cells. These results imply that the solitary electric field produced by time-varying MF is not a major cause of DSBs or apoptosis in cancer or normal cells.