• Title, Summary, Keyword: 마이크로파 송수신기

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Array Topology of Microwave Wireless Power Transmission on Electronic Power System (전력계통 연계를 대비한 마이크로파 무선전력 송수신기 에레이 구성 고찰)

  • Lee, Dongho
    • Journal of Satellite, Information and Communications
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    • v.10 no.1
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    • pp.88-91
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    • 2015
  • Wireless power transmission (WPT) is a technology using free space as a conductor for transmitting electric power, which aims to transfer not just the transmission signal but also the electrical energy itself. This paper takes issue with the microwave wireless transmission technology utilizing in long-distance transmission. To construct the WPT system, several components are needed, such as RF Oscillator which converts AC power to RF through DC status, high gain antenna and RF rectifier that converts RF back to DC. The array topology is good a candidate for wide use. The objective of this research is to study the efect of the WPT systmem on electric power system.

해양교통안전 확보를 위한 무지향성 전파발신기 개발

  • Kim, Jeong-Wan;Jin, Seong-Hyeon;Yang, Gyeong-Seong;Kim, Jong-Uk
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.114-116
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    • 2018
  • 선박용 레이더 주파수 대역에서 운영되고 어떤 레이더 물표의 탐지와 식별을 향상시키기 위한 송수신 겸용 장치(일종의 마이크로파 송수신기)로 해상의 선박에서 발사된 레이더 펄스를 수신한 후, 이 신호를 분석하여 분석된 신호에 대응되는 인식신호를 수신된 신호와 동일한 주파수의 전파에 변조시켜 응답하는 장치를 국산화 개발하였다.

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A Design of Variable Attenuator for MMIC using Slot in the Ground Plane (접지면의 슬롯을 이용한 마이크로파 집적회로용 가변 감쇠기의 설계)

  • 김기래
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.6
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    • pp.1109-1114
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    • 2003
  • In this paper, the electric characteristic of the SGPS with slot in the ground plane is similar to the parallel resonant circuit. When the slot length in SGPS is equal to the half wavelength of specific frequency, the characteristic of SGPS represent the large attenuation at the specific frequency. We found out the relation between attenuation and resistor on the slot in SGPS and we designed the variable attenuator for MMIC using the variable resistor. This attenuator can be applied to AGC circuit in transceiver if the PIN diode is used replace for resistor.

Microfabrication of Microwave Transceivers for On-Chip Near-Field Electromagnetic Shielding Characterization of Electroplated Copper Layers (극소형 전자기파 송수신기의 제작 및 전기도금된 구리박막의 칩단위 근접 전자기장 차폐효과 분석)

  • Gang, Tae-Gu;Jo, Yeong-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.6
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    • pp.959-964
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    • 2001
  • An experimental investigation on the near-field electromagnetic loss of thin copper layers has been presented using microfabricated microwave transceivers for applications to multi-chip microsystems. Copper layers in the thickness range of 0.2$\mu$m∼200$\mu$m have been electroplated on the Pyrex glass substrates. Microwave transceivers have been fabricated using the 3.5mm$\times$3.5mm nickel microloop antennas, electroformed on the silicon substrates. Electromagnetic radiation loss of the copper layers placed between the microloop transceivers has been measured as 10dB∼40dB for the wave frequency range of 100MHz∼1GHz. The 0.2$\mu$m-thick copper layer provides a shield loss of 20dB at the frequencies higher than 300MHz, whereas showing a predominant decreases of shield loss to 10dB at lower frequencies. No substantial increase of the shield effectiveness has been found for the copper shield layers thicker that 2 $\mu$m.

Measurement of Backscattering Coefficients of Rice Canopy Using a Ground Polarimetric Scatterometer System (지상관측 레이다 산란계를 이용한 벼 군락의 후방산란계수 측정)

  • Hong, Jin-Young;Kim, Yi-Hyun;Oh, Yi-Sok;Hong, Suk-Young
    • Korean Journal of Remote Sensing
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    • v.23 no.2
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    • pp.145-152
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    • 2007
  • The polarimetric backscattering coefficients of a wet-land rice field which is an experimental plot belong to National Institute of Agricultural Science and Technology in Suwon are measured using ground-based polarimetric scatterometers at 1.8 and 5.3 GHz throughout a growth year from transplanting period to harvest period (May to October in 2006). The polarimetric scatterometers consist of a vector network analyzer with time-gating function and polarimetric antenna set, and are well calibrated to get VV-, HV-, VH-, HH-polarized backscattering coefficients from the measurements, based on single target calibration technique using a trihedral corner reflector. The polarimetric backscattering coefficients are measured at $30^{\circ},\;40^{\circ},\;50^{\circ}\;and\;60^{\circ}$ with 30 independent samples for each incidence angle at each frequency. In the measurement periods the ground truth data including fresh and dry biomass, plant height, stem density, leaf area, specific leaf area, and moisture contents are also collected for each measurement. The temporal variations of the measured backscattering coefficients as well as the measured plant height, LAI (leaf area index) and biomass are analyzed. Then, the measured polarimetric backscattering coefficients are compared with the rice growth parameters. The measured plant height increases monotonically while the measured LAI increases only till the ripening period and decreases after the ripening period. The measured backscattering coefficientsare fitted with polynomial expressions as functions of growth age, plant LAI and plant height for each polarization, frequency, and incidence angle. As the incidence angle is bigger, correlations of L band signature to the rice growth was higher than that of C band signatures. It is found that the HH-polarized backscattering coefficients are more sensitive than the VV-polarized backscattering coefficients to growth age and other input parameters. It is necessary to divide the data according to the growth period which shows the qualitative changes of growth such as panicale initiation, flowering or heading to derive functions to estimate rice growth.