• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.224-226
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• 2019

본 논문은 BESS용 단상 인버터의 입력에 영향을 미치는 차동모드 노이즈에 대한 모델링을 제안하였으며, 이를 시뮬레이션으로 구현하였다. 이 방법은 적절한 노이즈원과 전달 임피던스 경로를 통해 구현되고, 단상 인버터의 개발 초기 단계에서 EMI 설계 과정을 최적화하여 개발 비용을 줄이는데 도움이 될 수 있다. 노이즈원 전류는 단상 인버터의 IGBT 스위칭에 대하여 모델링하였고, 차동모드 등가 회로를 통해 임피던스 경로를 해석하여 이 두 값의 곱으로 입력에 영향을 주는 차동 모드의 노이즈 전압을 도출하였다. 차동모드 노이즈의 모델링을 시뮬레이션과 실험의 비교를 통해 검증하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.1
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• pp.54-62
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• 1999

In this paper, we investigated the signal-to-noise ratio improvement in a differential detector, which is a function of the optical noise coupling ratio and the differential gain ratio. A differential detector consists of two photodiodes and a differential amplifier. The differential detector reduced the noise component and improved the signal-to-noise ratio by about 20 dB when the differential gain ratio equals to the optical noise coupling ratio. The differential detector is very effective in removing the environmental optical noise or interference from an adjacent optical channel. This method is also effective when the noise wavelength is similar to the signal.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.4
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• pp.602-610
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• 1993

The DDA of new active element and the DDA differential integrator are designed. The DDA can be improved matching problems of external elements in op-amp application circuits. The design of DDA is used the transconductance element, differential pair and $2{\mu}m$ design rule. In order to evaluate the performance of the CMOS DDA, we simulated the DDA voltage inverter and the DDA level shifter using the designed CMOS DDA. Furthermore, the grounded resistor and the differential integrator is designed using the CMOS DDA and we found that its characteristics are agreed to OP-AMP differential integrator's. We performed the layout of the CMOS DDA and DDA differential integrator with MOSIS $2{\mu}m$ CMOS technology.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.5
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• pp.879-886
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• 2008

This paper addresses the analysis and the design optimization of differential interconnects for Low-Voltage Differential Signaling (LVDS) applications. Thanks to the differential transmission and the low voltage swing, LVDS offers high data rates and improved noise immunity with significantly reduced power consumption in data communications, high-resolution display, and flat panel display. We present an improved model and new equations to reduce impedance mismatch and signal degradation in cascaded interconnects using optimization of interconnect design parameters such as trace width, trace height and trace space in differential flexible printed circuit board (FPCB) transmission lines. We have carried out frequency-domain full-wave electromagnetic simulations, time-domain transient simulations, and S-parameter simulations to evaluate the high-frequency characteristics of the differential FPCB interconnects. The 10% change in trace width produced change of approximately 6% and 5.6% in differential impedance for trace thickness of $17.5{\mu}m$ and $35{\mu}m$, respectively. The change in the trace space showed a little change. We believe that the proposed approach is very helpful to optimize high-speed differential FPCB interconnects for LVDS applications.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.2
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• pp.47-53
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• 2013

In this work, signal transmission properties of SATA connector have been improved using its differential impedance calculation and its design revision to closer impedance matching. Using 3 dimensional electromagnetic field simulator, the differential mode S-parameter was calculated to investigate its signal fidelity. The differential impedance is calculated from the equation of the odd mode impedance with inductance, capacitance, mutual inductance, and mutual capacitance. The differential impedance of SATA connector was calculated to be $107.3{\Omega}$ and did not meet the design specification with $100{\Omega}{\pm}5%$. In order to achieve its impedance range and improve its signal transmission properties, SATA connector's design has been revised with two different directions and analyzed through the calculation of differential impedance, differential reflection loss, and differential insertion loss.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.10
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• pp.70-78
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• 2009

This paper addresses the analysis and the design optimization of differential interconnects for high-speed Low-Voltage Differential Signaling (LVDS) applications. Thanks to the differential transmission and the low voltage swing, LVDS offers high data rates and improved noise immunity with significantly reduced power consumption in data communications, high-resolution display, and flat panel display. We present an improved model and new equations to reduce impedance mismatch and signal degradation in cascaded interconnects using optimization of interconnect design parameters such as trace width, trace height and trace space in differential printed circuit board (FPCB) transmission lines. We have carried out frequency-domain full-wave electromagnetic simulations, and time-domain transient simulations to evaluate the high-frequency characteristics of the differential FPCB interconnects. We believe that the proposed approach is very helpful to optimize high-speed differential FPCB interconnects for LVDS applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.761-764
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• 2007

This paper addresses the analysis and the design optimization of differential interconnects for Low-Voltage Differential Signaling (LVDS) applications. Thanks to the differential transmission and the low voltage swing, LVDS offers high data rates and improved noise immunity with significantly reduced power consumption in data communications, high-resolution display, and flat panel display. We present an improved model and new equations to reduce impedance mismatch and signal degradation in cascaded interconnects using optimization of interconnect design parameters such as trace width, trace height and πace space in differential flexible printed circuit board (FPCB) transmission lines. We have carried out frequency-domain full-wave electromagnetic simulations, time-domain transient simulations, and S-parameter simulations to evaluate the high-frequency characteristics of the differential FPCB interconnects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10A
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• pp.807-815
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• 2003

MultiCode-CDMA (MC-CDMA) system of chip level MPSK incorporating with clipper (MP-CDMA)[l] shows constant envelope signal which can mitigate the performance degradation due to nonlinear transmit amplifier. In this paper, modulation is modified to carry out differential encoded MPSK rather than MPSK. The modified system is called DMP-CDMA. DMP-CDMA using differential detection has advantages on receiver complexity and pilot overhead. However, it is inferior to coherent detection by about 4.0dB due to inherent power inefficiency of noncoherent detection and the error propagation. Multiple symbol differential detection is employed in order to improve DMP-CDMA using differential detection. As the result, the performance of DMP-CDMA system is improved about 3.6dB compared to differential detection.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.1 s.4
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• pp.117-125
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• 2004

Space-time coding and modulation exploit the presence of multiple transmit antennas to improve performance on multipath Rayleigh fading channels. In this paper, we propose the Trellis-Coded Differential Space Time Modulation-OFDM system with multiple symbol detection. The Trellis-code perform the set partition with unitary group codes. The Viterbi decoder containing new branch metrics is introduced in order to improve the bit error rate (BER) in the differential detection of the Unitary differential space time modulation. Also, we describe the Viterbi algorithm in order to use this branch metrics. Our study shows that such a Viterbi decoder improves BER performance without sacrificing bandwidth and power efficiency.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.5
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• pp.121-127
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• 2019

This paper proposes an operator-centric velocity generation and control algorithm for differential-drive mobile robots, which are widely used in many industrial applications. Most of the previous works use a robot centric velocity generation and control for the operators to control the differential-drive mobile robots, which makes the robot control difficult for the operators. Such robot-centric control can cause the increase of accidents and the decrease of work efficiency. The experimental results with a real differential-drive mobile robot testbed demonstrate the efficiency of operator-centric mobile robot control.