• Title, Summary, Keyword: RF Transmission

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Simulation Method for Radio-Frequency Single-Electron Transistor (RF-SET) Operation (고주파 단일전자 트랜지스터 (RF-SET) 동작의 시뮬레이션 방법)

  • Yu Yun Seop;Park Hyun-Sik
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.5
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    • pp.9-14
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    • 2005
  • Simulation method for a pure radio-frequency (rf) mode of reflection-type and a pure rf mode of transmission-type radio-frequency single-electron transistor (RF-SET) operation is introduced. In this method, the solutions of differential equations based on Kirchhoff's law are obtained self-consistently at frequency-domain. Also, the steady-sate single-electron transistor (SET) current model and the time-dependent SET current model are used in this method. The reflected wave of a typical reflection-type RF-SET and the transmitted wave of a typical transmission-type RF-SET are calculated, and the accuracy of our developed method including the steady-state SET current model is verified with the method introduced by reference 2. At high frequency over GHz, results of our developed method including the time-dependent SET current model are considerably different from that including the steady-state SET current model. At high frequency over GHz, an exact time-dependent SET current model is needed to analyze RF-SET operation.

RF Resonators Using Microstrip Transmission Line at 3 T MRI (3 T 자기공명영상시스템에서의 마이크로스트립을 이용한 다양한 RF 공진기)

  • Yoo, Hyoungsuk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.5
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    • pp.663-666
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    • 2013
  • This paper demonstrates four different radio frequency (RF) resonators at 3 T magnetic resonance imaging (MRI) system. An approach based on microstrip transmission line to identical RF resonators except upper stripline structure is investigated. Electromagnetic simulation results are compared for RF resonators and discussed in detail at 3 T.

A Development on Universal RF based Module for Wireless Network (계측 시스템의 무선통신을 위한 RF모듈 개발)

  • Park, Suk-Hyun;Shim, Woo-Hyuk;Seo, Young-Jo;Kim, Beung-Jin;Jeon, Hee-Jong
    • Proceedings of the KIEE Conference
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    • pp.3064-3066
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    • 1999
  • The existing equipment with wire communication can expect the stability of data transmission. However, according to increasing a number of DTE (Data Terminal Equipment), wiring work becomes a heavy burden. Restriction to application about portable DTE and the lack of flexibility are another drawback of wire communication. This paper presents the design and implementation of a RF (Radio Frequency) based wireless communication system. The RF based module is designed to the multi communication between DTEs. The RF based module consists of RF circuit and microprocessor. The main properties of RF circuit are maximum 5Kbps transmission rate, maximum 90m transmission distance and 433MHz frequency band. The microprocessor rearrange the data into AHDLC(Advanced High level Data Link Control) format and then instructs RF circuits to transmit/receive the data. The RF module have a wide application field such as fire/security alarm, remote control/measurement etc..

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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.

Changes of Afferent Transmission to the SI Cortex by Transient Co-Stimulation of Receptive Field Center and Outside in Anesthetized Rats

  • Yang, Yu-Mi;Lim, Sa-Bina;Won, Chung-Kil;Shin, Hyung-Cheul
    • The Korean Journal of Physiology and Pharmacology
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    • v.5 no.1
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    • pp.27-32
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    • 2001
  • We have characterized the aftereffects of impulse activities on the transmission of afferent sensory to the primary somatosensory (SI) cortex of the anesthetized rats (n=22). Following conditioning stimulation (CS, 10 sec, either 5 Hz or 200 Hz) to the receptive field (RF), quantitative determination of the changes of afferent sensory transmission was done by generating post-stimulus time histogram of unit response to the testing stimulation (TS, at 0.5 Hz) to the RF center (RFC) for 60 min. In one group of experiments, CS was delivered to the RF center (RFC). In another group of experiments, CSs were simultaneously given to both RFC and RF outside (RFO, either forepaw or hindpaw). CS of 5 Hz to RFC exerted irreversible facilitation of sensory transmissions evoked by TS. Simultaneous CSs of 5 Hz to RFC and hindpaw RFO exerted reversible suppression of afferent transmission. However, CSs of 5 Hz to RFC and forepaw RFO did not significantly altered afferent sensory transmission to SI cortex neurons. CS of 200 Hz to RFC exerted irreversible suppression of sensory transmissions up to 60 min of experimental period. Simultaneous CSs of 200 Hz to RFC and RFO did not significantly altered afferent sensory transmission to SI cortex neurons. The profiles of CS-induced modulation of afferent sensory transmission were significantly different between two CS conditions. Thus, this study suggests that activity-dependent modulation of afferent transmission from a RF center to the SI cortex may be significantly altered when remote body part was simultaneously activated.

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Study on RF characteristics of voltage-controlled artificial transmission line employing periodically arrayed diodes for application to highly miniaturized wireless communication systems (초소형 무선 통신 시스템에서의 응용을 위한 주기적으로 배열된 다이오드를 이용한 전압제어형 전송선로의 RF 특성에 관한 연구)

  • Kim, Soo-Jeong;Kim, Jeong-Hoon;Jeong, Jang-Hyeon;Yun, Young
    • Journal of Advanced Marine Engineering and Technology
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    • v.41 no.1
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    • pp.70-75
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    • 2017
  • In this paper, we studied the RF characteristics of a voltage-controlled artificial transmission line employing periodically arrayed diodes for application to highly miniaturized wireless communication systems on an MMIC (monolithic microwave integrated circuit). According to the results, the novel voltage-controlled artificial transmission line employing periodically arrayed diodes exhibited a short wave length, which was only 35.2% that of the conventional transmission line, owing to increasing capacitance. In addition, it's effective permittivity and effective propagation constant exhibited considerably higher values than those of the conventional transmission line. Furthermore, attenuation constant of the voltage-controlled artificial transmission line was far higher than that of the conventional transmission line. Using the closed-form equation, we theoretically analyzed the equivalent circuit of the voltage-controlled artificial transmission line.

The Influence of Noise Environment upon Voice and Data Transmission in the RF-CBTC System

  • Kim, Min-Seok;Lee, Sang-Hyeok;Lee, Jong-Woo
    • International Journal of Railway
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    • v.3 no.2
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    • pp.39-45
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    • 2010
  • The RF-CBTC (Radio Frequency-Communication Based Train Control) System is a communication system in railroad systems. The communication method of RF-CBTC system is the wireless between the wayside device and on-board device. The wayside device collects its location and speed from each train and transmits the distance from the forwarding train to the speed-limit position to it. The on-board device controlling device controls the speed optimum for the train. In the case of the RF-CBTC system used in Korea, transmission frequency is 2.4 [GHz]. It is the range of ISM(Industrial Scientific and Medical equipment) band and transmission of voice and data is performed by CDMA (Code Division Multiple Access) method. So noises are made in the AWGN (Additive White Gaussian Noise) and fading environment. Currently, the SNR (Signal to Noise Ratio) is about 20 [dB], so due to bit errors made by noises, transmission of reliable information to the train is not easy. Also, in the case that two tracks are put to a single direction, it is needed that two trains transmit reliable voice and data to a wayside device. But, by noises, it is not easy that just a train transmits reliable information. In this paper, we estimated the BER (Bit Error Rate) related to the SNR of voice and data transmission in the environment such as AWGN and fading from the RF-CBTC system using the CDMA method. Also, we supposed the SNR which is required to meet the BER standard for voice and data transmission. By increasing the processing gain that is a ratio of chip transmission to voice and data transmission, we made possible voice and data transmission from maximally two trains to a wayside device, and demonstrated it by using Matlab program.

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Monopulse Receiver Design with Adaptive Transmission Speed on Ku-Band (적응형 전송속도를 갖는 Ku-대역 모노펄스 수신기 설계)

  • Jeong, Byeoung-Koo;Lee, Dae-Hong;Joo, Tae-Hwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.7
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    • pp.500-507
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    • 2018
  • A three-channel radio frequency (RF) monopulse receiver using a data signal with a maximum transmission rate of 274 Mbps was designed. A monopulse receiver using a broadband communication signal was designed to operate in the Ku band, and it consists of a down-conversion module and a signal-processing module. To satisfy the performance of the proposed RF monopulse receiver, a signal-processing function less than the reception sensitivity for each transmission rate according to the adaptive transmission rate is required. To minimize signal reception and mutual frequency interference of various bandwidths, two RF filters were applied. To verify the satisfaction of system requirements, an AWR Corp. simulation tool was used.

Study on conversion efficiency of RF-DC converter with series diode (직렬 연결 RF-DC 변환기의 변환효율에 관한 연구)

  • Choi, Ki-Ju;Hwang, Hee Yong
    • Journal of Industrial Technology
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    • v.30 no.A
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    • pp.69-73
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    • 2010
  • In this paper, we designed the RF-DC converter used in wireless power transmission system and studied how to design the RF-DC converter of high conversion efficiency. The RF-DC converter operate at 2.45GHz and the diode is connected with series. The RF-DC converter uses shorted stub for DC loop and matching. We can divide the RF-DC converter circuit into four blocks. The reflection coefficients between the blocks were optimized for the maximum conversion efficiency at 0 dBm input power and $1300{\Omega}$ load impedance. The final design of the RF-DC converter has a 52 percent conversion efficiency.

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Study on Characteristics of Various RF Transmission Line Structures on PES Substrate for Application to Flexible MMIC

  • Yun, Young;Kim, Hong Seung;Jang, Nakwon
    • ETRI Journal
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    • v.36 no.1
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    • pp.106-115
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    • 2014
  • In this work, the coplanar waveguide is fabricated on a PES (poly[ether sulfone]) substrate for application to a flexible monolithic microwave integrated circuit, and its RF characteristics were thoroughly investigated. The quality factor of the coplanar waveguide on PES is 40.3 at a resonance frequency of 46.7 GHz. A fishbone-type transmission line (FTTL) structure is also fabricated on the PES substrate, and its RF characteristics are investigated. The wavelength of the FTTL on PES is 5.11 mm at 20 GHz, which is 55% of the conventional coplanar waveguide on PES. Using the FTTL, an impedance transformer is fabricated on PES. The size of the impedance transformer is $0.318mm{\times}0.318mm$, which is 69.2% of the size of the transformer fabricated by the conventional coplanar waveguide on PES. The impedance transformer showed return loss values better than -12.9 dB from 5 GHz to 50 GHz and an insertion loss better than -1.13 dB in the same frequency range.