• Title, Summary, Keyword: 400MHz

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Narrow-Band Analog Pre-Distortion Linearization Technique using UHF 400 MHz Band 20 W Power Amplifier (UHF 400 MHz 대역 20 W급 전력증폭기를 이용한 협대역 아날로그 전치왜곡 선형화 기법)

  • Ha, Jung-wan;Kim, Kang-san;Kim, Hyo-Jong
    • The Journal of Advanced Navigation Technology
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    • v.23 no.2
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    • pp.179-185
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    • 2019
  • In this paper, we have studied narrow-band analog pre-distortion linearization technique using UHF 400 MHz band 20 W power amplifier. The analog pre-distorter used the SC1894 radio frequency power amplifier linearizer(RFPAL) provided by MAXIM Corp and through the look-up table technique confirmed the intermodulation distortion(IMD) performance and the adjusted channel leakage ratio(ACLR) improvement for bandwidth below 1 MHz which does not operate on existing chips. In the 400 MHz (400 ~ 500 MHz) band, IMD performance and the ACLR improvement of up to 17.46 dB based on 1-channel offset and up to 16.6 dB based on 2-channel offset were confirmed. In the system requiring the same linearity, we confirmed power efficiency improvement of 12.41% at output power of over 40 W.

Design and Fabrication of 400MHz ISM-Band GFSK Transceiver for Data Communication (400MHz ISM대역 데이터 통신용 GFSK 송.수신기 설계 및 제작)

  • Lee, Hang-Soo;Jang, Rae-Kyu;Hong, Sung-Yong;Lee, Seung-Min
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • pp.401-406
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    • 2005
  • The GFSK Transceiver of 400MHz ISM band for data communication is designed and fabricated. To reduce the occupied bandwidth of transmitted signal, the GFSK modulation is selected. The measured results of fabricated transceiver show the data rate of 2400bps at 8.5kHz bandwidth, frequency deviation of less than $\pm$3kHz, sensitivity of -111dBm, SNR of 21.58dB. The fabricated transceiver is satisfied with the regulation of radio wave and has the good performance. This transceiver is well suited for data communication of 400MHz ISM band.

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Analysis of Distortion Characteristic of Amplitude Modulated Signal through a Current-Mode-Logic Frequency Divider (전류모드논리 주파수 분할기를 통한 기저대역 AM 변조 신호의 왜곡 특성 연구)

  • Kim, Hyeok;Park, Youngcheol
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.7
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    • pp.620-624
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    • 2016
  • In this paper we designed a current mode logic frequency divider to transmit a baseband amplitude modulated signal. From simulation result, we studied input and output waveforms according to the variation of input bias voltage. For the purpose of the verification of the study, we designed a current mode logic frequency divider at 1,400 MHz. The designed frequency divider operates between 100 MHz and 3,000 MHz, for -33 dBm input power. The circuit draws $I_{total}=30mA$ from $V_{DD}=3V$ supply, and the simulation result shows that an amplitude modulated signal at 1,400 MHz with the modulation index of 0.5 was successfully downconverted to 700 MHz.

Frequency Adaptive High Efficiency Class-E Amplifier in 400 MHz Range (400MHz 대역의 주파수 적응형 고효율 Class-E 증폭기)

  • Ryu, Jae-Hyun;Son, Kang-Ho;Kim, Young;Yoon, Young-Chul
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.673-675
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    • 2010
  • This paper proposes the adaptive class-E power amplifier with maintaining high power added efficiency (PAE) in 400MHz range. This amplifier is used a microprocessor to adapt a resonator circuits and to maintain high efficiency in case of input frequency variation. To validate the adaptive amplifier operation, which is a 450MHz operating frequency and a 100MHz bandwidth, the class E amplifier is implemented. As a result, the adaptive amplifier is maintained above 60% efficiency and has a 74.8% maximum efficiency.

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Design and Fabrication of 400 MHz ISM-Band GFSK Transceiver for Data Communication (400 MHz ISM 대역 데이터 통신용 GFSK 송·수신기 설계 및 제작)

  • Lee Hang-Soo;Hong Sung-Yong;Lee Seung-Min
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.2
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    • pp.198-206
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    • 2006
  • The GFSK Transceiver of 400 MHz ISM band for data communication is designed and fabricated. To reduce the occupied bandwidth of transmitted signal, the GFSK modulation is selected. The measured results of fabricated transceiver show the data rate of 2,400 bps at 8.5 kHz bandwidth, frequency deviation of less than ${\pm}3\;kHz$, sensitivity of -107 dBm at SINAD of 20 dB, BER of less than $1.8{\times}10^{-3}$ at -110 dBm input power. The fabricated transceiver is satisfied with the regulation of radio wave and has the good performance.

A Small Broadband Antenna for Wibro/WLAN/Mobile WiMAX (Wibro/WLAN/Mobile WiMAX용 소형 광대역 안테나)

  • Ko, Jeong-Ho;Choi, Ik-Guen
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.5
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    • pp.568-575
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    • 2011
  • In this paper, we propose a small broadband antenna for mobile device. The proposed antenna consists of a printed rectangular monopole antenna and a parastic element connected to ground using narrow meander line and it is designed on a FR-4 substrate that has a thickness of 0.8 mm and a dielectric constant of 4.4. The FR-4 substrate's size is 50 mm${\times}$90 mm comparable to the real mobile device. The fabricated antenna's size is 12.5 mm${\times}$10.5 mm${\times}$0.8 mm and the measurement shows -10 dB return loss bandwidth of 2,200~6,000 MHz and gains of 2.86~4.01 dBi. Accordingly, the proposed antenna can support mobile device for WiBro(2,300~2,380 MHz), WLAN(IEEE 802.11b/g/n: 2,400~2,480 MHz, IEEE 802.11a: 5,150~5,825 MHz), and mobile WiMAX(IEEE 802.16e : 2,500~2,690 MHz, 3,400~3,600 MHz) service bands.

A Study on Fabrication and Characteristics of PZT Probe for Nondestructive Test (비파괴 검사를 위한 PZT 탐촉자의 제작 및 특성에 관한 연구)

  • 김철수;정규원;송준태
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.8
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    • pp.613-619
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    • 1998
  • Ultrasonic probes of 400kHz, 1MHz were fabricated using PZT-5Z plates. Epoxy was used for backing layer materials onthe plates. Nondestructive Test was carried using these probes. Pulse lobe width of impulse response was reduced 15.4% compare 1MHz with 400kHz and 96.6% compare 3MHz with 400kHz. The attenuation in aluminum was 2.05[dB/m] at 400kHz, 4/91[dB/m] at 1MHz, 7.35[dB/m] at 3HMz. Hole detection error of the first hole was 22.4% at 1HMz, 9.% at 3HMz, The second hole 11.6% at 1HMz, 4.7% at 3HMz. In the result of experiment of the hole detection error and resolution, 3HMz probe was the best among them.

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Analysis of Corner Reflector Antennas feeding by Log-Periodic Dipole Antennas (대수주기 다이폴안테나로 급전되는 코너리플렉터안테나의 해석)

  • 최학윤
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.7A
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    • pp.511-519
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    • 2003
  • In this paper, to achieve a broad-band and high-gain antenna, we thus designed and analyzed the CRLPDA(Corner Reflector Antenna feeding by Log-Periodic Dipole Antenna) made up of 90$^{\circ}$corner reflector, which is trough-reflector type installed a planar reflector at the folded line. CRLPDA for operating frequency band of 1,400 MHB ~ 2,400 MHz was designed and radiation characteristics of the designed antenna were analyzed by moment method. To verify the analysis results, CRLPDA was fabricated and the calculated results were compared with the measured results. The measured results showed good agreement with the calculated results. As the result of measurements, bandwidth(VSWR>2) for 1,000 MHz was achieved and gain was 13 dBi.

The design of bent monopole antenna for 400MHz ISM band applications (400MHz ISM대역용 굴곡형 모노폴 안테나의 설계)

  • Lee, Young-Soon
    • The Journal of Advanced Navigation Technology
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    • v.15 no.2
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    • pp.189-196
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    • 2011
  • In order to subsitute for the normal mode helical wire antenna, bent monopole antenna combined with a helical structure is proposed as a kind of printed antenna. The antenna which can be operated at 418MHz has been simulated and designed by use of a commercial EM simulator Microwave Studio(MWS). It has been observed that the proposed antenna has good agreements between simulated results and measured results such as the return loss and the radiation pattern. The proposed antenna has been applied practically to the wireless remote controller operationg at 418MHz. It has been observed that the use of the proposed antenna result in similar antenna performance from view point of radiation power when compared with the use of the previous normal mode helical antenna.

A Filter Synthesis Method for Multi-Band Filter Design (다중 대역 필터 설계를 위한 필터 합성법)

  • Lee, Hye-Sun;Lee, Ja-Hyeon;Lim, Yeong-Seog
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.11
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    • pp.1259-1268
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    • 2010
  • In this paper, we presented a new LC prototype synthesis method for the multi-band filter. For synthesis a multi-band filter with the required frequency response, we proposed the diagram of poles and zeros, also, we proposed the optimization process for finding the combination of optimized poles and zeros. From the transfer and reflection functions calculated from poles and zeros, we performed the quasi-elliptic LC prototype synthesis of multi-band filter. Using the proposed LC prototype synthesis method of multi-band filter, dual-band filter operating at GSM(880~960 MHz) and ISM(2,400~2,500 MHz) and triple-band filter operating at GSM(880~960 MHz) and ISM(2,400~2,500, 5,725~5,850 MHz) were designed and fabricated.