• 한국통신학회논문지
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• 제25권7A호
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• pp.1057-1062
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• 2000

Allow me to introduce the development of an FM transmitter. The transmitter uses millmeter waves at the frequency of 60 GHz, and it can produce as much as 20 mW power with the band width of 1 GHz. The great feature of the FM transmitter is that it has been created by the special technique of utilizing the NRD (non radiative dielectric) waveguide. The advantage of adopting the NRD waveguide is that it can significantly reduce transmission loss. We can construct a small-size NRD guide transmitter in a simple way that has superb transmission performance. The NRD guide transmitter is very useful for CATV transmission or transmission over a wide range. In addition, the transmitter has almost the same band width as optical communication, and the data transmission speed of the transmitter is faster than that of optical communication. A transmitter with these merits would be highly appreciated as a way of ultra-highspeed communication network over short distances.

• 전자공학회논문지A
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• 제28A권10호
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• pp.806-813
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• 1991

In this paper, we suggested the diagnosis of the optical FSK transmitter output characteristics using the Micheloson interferometer. The transmitter is designed by the direct frequency modulation effect of a semoconductor laser diode. The optical FSK transmitter consists of a temperature stabilized semiconductor laser diode and an optimally designed equalizer. It is modulated by 100Mbit/s PRBS Generator to diagonosis of Optical FSK transmitter output characteristics. The Michelson Interferometer is used for the optical frequency discriminator which transforms the output frequency of the transmitter to the amplitude of light. The measurement of the performance of the transmitter to the amplitude of light. The measurement of the performance of the transmitter computer the transmitted data and their eye pattern with the simulation results, the received data and their eye pattern. As the result of experiment, the data transfer rate of the transmitters is 100Mbit/s.

• 전기학회논문지
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• 제61권3호
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• pp.384-393
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• 2012

Railroad signaling systems perform controlling the distance and routes between trains. Signaling methods on the wayside are to control passively the train speed by using signal flags which are installed on the wayside. ATS(Automatic Train Stop) device is used as the signaling method on the wayside in Korea. The ATS device is assistance equipment of engineers. Signal information is transmitted by combining mutual inductance between the wayside transmitter and on-board receiver. The wayside transmitter performs changing oscillation frequency according to the signal information. The on-board receiver performs controlling the train by receiving the frequency. Currently, the oscillation frequency on the on-board receiver is 78[kHz] in case of normal state. When the on-board receiver is over the wayside transmitter, the oscillation frequency is changed by capacitors of the wayside transmitter according to signal flags. In case of changing the oscillation frequency, the waveform is modified in the wayside transmitter and on-board receiver. This phenomenon is that other signals or communication frequency are included. In this paper, electric model between the wayside transmitter and on-board receiver is suggested and frequency response in the wayside transmitter and on-board receiver including other signals is estimated by the coupling coefficient. Also, the value of coupling coefficient is proposed to exclude other signals and demonstrated by using Matlab and PSpice program.

• 전기학회논문지P
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• 제63권3호
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• pp.206-211
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• 2014

In this Paper, We proposed the HLS(Http Live Streaming) transmitter which is operated easily and cheap in all networks and client environments compared to the exist video live streaming transmitter. We analyzed the HLS protocol and then implemented for making the HLS transmitter cheaper and portable. After designing the HLS transmitter hardware using the RISC processor of Arm11 core, we ported the Linux Operating System and implemented the HLS protocol using the open source FFmpeg and Segmenter. For the performance evaluation of the developed HLS transmitter, we made the testing environment which is including the notebook, iPhone, and aroid Phone. In this testing environment, we analysed the received video data at the client displayer. As a results of the performance evaluation, we could certify that the proposed HLS transmitter has a higher performance than the Apple company's HLS.

• ETRI Journal
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• 제45권1호
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• pp.150-162
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• 2023

The polar delta-sigma modulator (DSM) transmitter architecture exhibits good coding efficiency and can be used for software-defined radio applications. However, the necessity of high clock speed is one of the major drawbacks of using this transmitter architecture. This study proposes a low-complexity timeinterleaved architecture for the polar DSM transmitter baseband part to reduce the clock speed requirement of the polar DSM transmitter using an upsampling technique. Simulations show that using the proposed four-branch timeinterleaved polar DSM transmitter baseband part, the clock speed requirement of the transmitter is reduced by four times without degrading the signal-tonoise-and-distortion ratio.

• International journal of advanced smart convergence
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• 제10권4호
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• pp.45-51
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• 2021

Polar transmitter can support multi-band and multi-mode operation. The efficiency of frequency usage can be increased if polar transmitters can transmit multi-carrier signals. In this paper the configuration of polar transmitters is investigated to generate multi-carrier signals. Spectrum and CCDF Simulation results of two-carrier signals generated by the polar transmitter can be used to design of PM and AM path in a polar transmitter.

• 전력전자학회논문지
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• 제25권3호
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• pp.181-187
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• 2020

In this study, we propose a spherical flux concentration structure for omnidirectional wireless power transfer. Omnidirectional wireless power transfer technology is a method that can transmit power to a transmitter located in an arbitrary position in a two-dimensional or three-dimensional space. However, to improve the power transfer distance in a wireless power transfer system, the diameter of the coil or the number of windings must increase, thereby increasing the size of the transmitter. The proposed transmitter structure adds a ferrite core inside the transmitter coil so that the magnetic flux generated by the transmitter is directed toward the position of the receiver. As a result, the flux linkage and the mutual inductance increase. By implementing the omnidirectional wireless power transfer system using the proposed structure, the power transfer distance can be improved by 65% compared with the conventional system without increasing the size of the transmitter. Simulation shows that the proposed spherical flux concentration structure increases the mutual inductance of the omnidirectional wireless power transmission system.

• 대한전자공학회논문지SD
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• 제46권11호
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• pp.84-91
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• 2009

본 논문은 multi-level signaling을 이용한 high speed serial link transmitter에 관하여 제안하였다. High speed serial link에서 수 Gb/s를 달성하기 위해 4-pulse amplitude modulation (PAM) 을 사용하였다. 4-PAM은 4개의 level로 한 symbol time에 2 bit data를 전송함으로써 binary signaling보다 2배 빠른 data 전송이 가능해졌다. 제안된 4-PAM transmitter는 전압 output 대신 전류 output을 생성하며 이로 인해 driver의 switching time이 빨라져서 더 높은 속도의 transmitter를 구현할 수 있었다. $2^5-1$ pseudo-random bit sequence (PRBS) 생성기는 built-in self test (BIST)를 하기 위해 on-chip으로 설계되었다. 본 연구는 동부 하이텍 $0.18{\mu}m$ CMOS 공정을 통하여 설계되었으며 1.8 V supply voltage에서 eye 크기가 160 mV 이고 최대 동작 속도는 8 Gb/s이다. 칩 전체 면적은 $0.7\times0.6mm^2$이며 전력 소모는 98 mW이다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.914-918
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• 2000

In this paper, a next generation high speed QPSK transmitter is designed based on 1.8${\mu}$m design rule. The designed transmitter supports the MPEG2-TS coded packed data for the DAVIC standard. Transmitter is composed of the convolutional coder, the shortened Reed-Solomon coder, and QPSK modulator. The coded packets are modulated in APSK with an RC filter. Especially, Galois Field multiplier with a standard basis is designed with the pipelined parallel architecture. Also, in the QPSK modulator, the RC filter and mixer are simplified into the ROM table, which can improve the performance of the transmitter. The total number of gates for the implemented baseband transmitter is 26,875.

• 전자공학회논문지SC
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• 제43권2호
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• pp.28-32
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• 2006

최근 고화질의 카메라가 장착된 휴대폰이 빈번하게 출시되고 있다. 휴대폰으로 고화질의 동영상 촬영은 가능하지만 그 동영상을 컴퓨터와 휴대폰 이외의 다른 영상장치에서는 무선 전송을 통해 재생시킬 방법이 없다. 따라서 본 논문에서는 휴대폰으로 촬영한 동영상을 고정식 TV뿐만 아니라 이동식 TV에서도 재생 가능케 하는 NTSC TV transmitter module을 설계 및 제작하고자 한다. NTSC transmitter module은 휴대폰에서 재생되는 동영상의 영상 및 음성 신호를 받아 NTSC TV의 CH4 방식으로 변조한 뒤, 이 신호를 무선으로 전송함으로써 TV에서도 휴대폰 동영상을 시청할 수 있다는 장점이 있다. 그러나 NTSC TV transmitter module은 안테나의 길이가 길고 잡음에 민감한 단점이 있다. 향후 TV 신호의 송수신 RF 분야의 지속적인 연구를 통해 안테나의 설계와 TV 신호의 왜곡 및 잡음 문제를 해결한다면 본 NTSC TV transmitter module은 휴대폰뿐만이 아닌 캠코더, DVD 플레이어 등의 많은 영상기기에 응용 가능할 것으로 예상된다.