• Title/Summary/Keyword: HFSS

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Development and Validation of Food Security Measure (식품 보장 측정의 개발과 타당도 연구)

  • Kim, Ki-Rang;Kim, Mi-Kyung
    • Journal of Nutrition and Health
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    • v.42 no.4
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    • pp.374-385
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    • 2009
  • This study aims to develop an index of food security in order to assess food security status in Korea and to evaluate reliability and validity of the index. The index of food security was developed based on the US Household Food Security Survey Module (US-HFSS). After the US-HFSS was translated and back-translated, it was evaluated and modified by a focus interview for experts. The developed Korean Household Food Security Survey Module (K-HFSS) was tested by cognitive interviews and a pretest for general community population to assess its application for Korean population. For the reliability and validity of K-HFSS, the survey was conducted with 300 adults aged 40 years or more living in a rural community and 212 infants and toddlers living in an urban community. The reliability was assessed by Cronbach' alpha and the validity was evaluated by content validity, construct validity, and criterion-related validity. The questionnaire items of K-HFSS were partly modified, accounting for Korean social and cultural backgrounds and adapted by general community population. The reliability was relatively high, showing Cronbach' alpha coefficients ranged from 0.80 (for adults) to 0.87 (for infants and toddlers). The content and construct validities were all acceptable. The result of criterion-related validity showed that food security status was significantly related to the household income level. In conclusion, the K-HFSS would be used as a reliable and valid instrument to assess food security status in parts of the Korean population.

Development of UHF RFID Ceramic Antenna Using HFSS (HFSS를 이용한 UHF RFID 세라믹 안테나 개발)

  • Hwang, Gi-Hyun;Cha, Kyung-Hwan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.1
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    • pp.193-198
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    • 2009
  • In this paper, we report the design of UHF RFID ceramic antenna using HFSS, one of the widely used RFID design tools. Of the developed antenna system, we analyze its Return Loss using HFSS and its characteristics using Smith Chart methodology. We built the ceramic antenna system based on the HFSS design, and analyzed its performance by measuring the impedence matching and gains using Network Analyzer. We attach the developed prototype to UHF RFID portable terminal, and performed distance measuring for five widely used types of RFID tags to verify the performance of our proposed antenna system.

Implementation of 6-Element High Power Cavity Filter for T-DMB (T-DMB 송신용 고출력 6소자 Cavity Delay Filter의 구현)

  • Go, Nam-Gyu;Son, Tae-Ho;Lee, Yong-Chang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.1
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    • pp.173-179
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    • 2012
  • In this study, cavity filter performing BPF function in Korea T-DMB system was designed by using of HFSS simulation tool, and we compared measured results with the simulated data. By simulation of HFSS that is magnetic and electric 3D simulating tool, we can save time and money maximumly by checking performances before actual filter implementation. Optimum conditions for the cavity filter were delivered based on the cylindrical waveguide characteristics. Measured results by implementation were compared with the simulation data.

Design of K-band VCO using HFSS modeling of dielectric resonator and frequency doubler (유전체 공진기의 HFSS 모델링을 이용한 2체배된 K밴드 VCO 연구)

  • 강성민;전종환;구경헌
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2002.11a
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    • pp.7-10
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    • 2002
  • This paper presents a design of 24㎓ GaAs MESFET voltage controlled oscillator using a dielectric resonator(DR) and a frequency doubler. DR modeling has been done to get the effects of resonator size and the gap from transmission line by HFSS at 12㎓, and frequency doubler is used to get 24㎓ Output.

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Implementation of a T-DMB Single Element Cavity Filter Using HFSS (HFSS를 이용한 T-DMB용 단일소자 공동여파기 구현)

  • Go, Nam-Gyu;Son, Tae-Ho;Lee, Yong-Chang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.6
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    • pp.157-162
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    • 2011
  • In this study, we design and implement a cavity filter for the Korea T-DMB broadcasting transmitter station and repeater system. HFSS 3 dimensional field simulation tool is used for this study. T-DMB filter has to be high quality factor Q, and cavity filter is applying in T-DMB system due to high handling power. We use HFSS simulation tool for design to obtain exact resonant frequency with easy design. A cavity filter is implemented based on the simulated results, and test results are compared with simulations. Measured resonant frequency and bandwidth are 211.8MHz and 0.1MHz, and correspond with design values.

Implementation of a T-DMB Single Element Cavity Filter Using HFSS (HFSS를 이용한 T-DMB용 단일소자 공동여파기 구현)

  • Go, Nam-Gyu;Son, Tae-Ho;Lee, Yong-Chang
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.6
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    • pp.91-97
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    • 2011
  • In this study, we design and implement a cavity filter for the Korea T-DMB broadcasting transmitter station and repeater system. HFSS 3 dimensional field simulation tool is used for this study. T-DMB filter has to be high quality factor Q, and cavity filter is applying in T-DMB system due to high handling power. We use HFSS simulation tool for design to obtain exact resonant frequency with easy design. A cavity filter is implemented based on the simulated results, and test results are compared with simulations. Measured resonant frequency and bandwidth are 211.8MHz and 0.1MHz, and correspond with design values.

A CPS-type Microstrip Patch Antenna Design for 910MHz RFID Tags (CPS구조를 갖는 910MHz 대역 RFID Tag용 마이크로스트립 패치 안테나 설계)

  • Son, Myung-Sik;Cho, Byung-Mo
    • Journal of IKEEE
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    • v.12 no.3
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    • pp.144-150
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    • 2008
  • This paper describes the design of a coplanar-stripline(CPS) antenna without via hole in microstrip patch type for 910MHz RFID tags using the HFSS simulator. In order to obtain the simplified fabrication design of the antenna, we have used only an impedance matching network to match the impedance of a RFID-tag chip to that of the antenna, not using bandpass filter(BPF). In advance of the optimized antenna design, we have obtained and shown a good agreement compared with the published antenna for 5.8GHz in order to verify the simulation parameters in the HFSS. Based on the verified simulation parameters in the HFSS, we have designed and optimized the 910MHz-CPS-type microstrip patch antenna. The designed simulation results of the antenna show that the proposed antenna is very proper for RFID tags with the 910MHz center frequency without via hole in the microstrip patch antenna.

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Characteristics of DTV Antenna (디지털 TV용 안테나 특성)

  • Park, Yong-Wook;Shin, Hyun-Yong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.2
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    • pp.119-124
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    • 2010
  • In this paper, microstrip antenna for Digital TV from 406 to 806 MHz has been designed and fabricated. In order to broaden the bandwidth of the antenna and improve of frequency properties, slot size, radius for capacitance controls were changed. DTV antenna was designed using HFSS simulation program and fabricated by FR4 substrate of dielectric constant 4.4.

The microstrip antenna for 5GHz (5GHz 대역 마이크로 스트립 안테나)

  • Park, Yong-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.12
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    • pp.5827-5831
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    • 2011
  • In this paper, 5Ghz microstrip patch antenna for wireless LAN is designed, fabricated, and measured. To obtain wide bandwidth and high gain, antenna parameters such as patch size(W, L), the length of the slot(C), and the slot width(D) are simulated by HFSS(High Frequency Structure Simulator). From these parameters optimized, the microstrip patch antenna is fabricated using FR-4 substrate. The measured results of the antenna are as follows: The center frequency of 5.2 GHz, insertion loss of -41.17dB, bandwidth of 258MHz, and VWSR of 1.1.

Characteristics of UHF Antenna with microstrip structure (UHF 대역용 마이크로 스트립 안테나 특성)

  • Park, Yong-Wook
    • Journal of the Korea Computer Industry Society
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    • v.9 no.5
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    • pp.217-222
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    • 2008
  • The characteristics of UHF antenna with microstrip structure was studied. Design parameters as center frequency, band width, and VSWR by slot length, stub was analyzed by HFSS simulator. UHF antenna with microstrip structure was fabricated using FR4_epoxy substrate of 4.4 dielectric constant.

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