http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
정전 용량형 MEMS 공진기의 비이상적 주파수 응답 모델링
고형호 ( Hyoung Ho Ko ) 한국센서학회 2010 센서학회지 Vol.19 No.3
In this paper, modeling of the non-ideal frequency response, especially “notch-and-spike” magnitude phenomenon and phase lag distortion, are discussed. To characterize the non-ideal frequency response, a new electro-mechanical simulation model based on SPICE is proposed using the driving loop of the capacitive vibratory gyroscope. The parasitic components of the driving loop are found to be the major factors of non-ideal frequency response, and it is verified with the measurement results.
Extended SBM 공정을 이용하여 단일 실리콘 기판상에 제작된 새로운 z축 가속도계
고형호 ( Hyoung Ho Ko ),김종팔 ( Jong Pal Kim ),박상준 ( Sang Jun Park ),곽동훈 ( Dong Hun Kwak ),송태용 ( Tae Yong Song ),조동일 ( Dong Il Cho ),허건수 ( Kun Soo Huh ),박장현 ( Jahng Hyon Park ) 한국센서학회 2004 센서학회지 Vol.13 No.2
N/A This paper presents a novel z-axis accelerometer with perfectly aligned vertical combs fabricated using the extended sacrificial bulk micromachining (extended SBM) process. The z-axis accelerometer is fabricated using only one 1111) SOI wafer and two photo masks without wafer bonding or CMP processes as used by other research efforts that involve vertical combs. In our process, there is no misalignment in lateral gap between the upper and lower comb electrodes, because all critical dimensions including lateral gaps are defined using only one mask. The fabricated accelerometer has the structure thickness of 30 gm, the vertical offset of 12 gm, and lateral gap between electrodes of 4 gm. Torsional springs and asymmetric proof mass produce a vertical displacement when an external z-axis acceleration is applied, and capacitance change due to the vertical displacement of the comb is detected by charge-to-voltage converter. The signal-to-noise ratio of the modulated and demodulated output signal is 80 dB and 76.5 dB, respectively. The noise equivalent input acceleration resolution of the modulated and demodulated output signal is calculated to be 500 gg and 748.tg. The scale factor and linearity of the accelerometer are measured to be 1.1 mV/g and 1.18% FSO, respectively.
적응형 가변 전원 레귤레이터를 내장한 인공 망막용 전류 자극기
고형호 ( Hyoung Ho Ko ) 한국센서학회 2011 센서학회지 Vol.20 No.4
In this paper, a current stimulator circuit with adaptive supply regulator for retinal prosthesis is proposed. In current stimulation systems, the stimulating circuits with wide voltage swing range are needed due to the high impedance of the retina cell and microelectrodes. Thus, previous researches adopt the high voltage architecture to obtain the enough operating range. The high voltage architecture, however, could increase the power consumption and can damage the retina cells. The proposed circuit provides the adaptively regulated supply voltage by measuring the difference between desired stimulation current and the actual stimulation current. The proposed circuit can achieve the extended range of the allowable cell impedance, improved accuracy of the stimulation current, and higher biosafety.
Feedback Control for Expanding Range and Improving Lineraity of Microaccelerometers
박용화,박상준,최병두,고형호,송태용,임근원,허건수,박장현,조동일,Park, Yong-Hwa,Park, Sang-Jun,Choi, Byung-Doo,Ko, Hyoung-Ho,Song, Tae-Yong,Lim, Genu-Won,Huh, Kun-Soo,Park, Jahng-Hyon,Cho, Dong-il Institute of Control 2004 제어·로봇·시스템학회 논문지 Vol.10 No.11
This paer presents a feedback-controlled, MEMS-fabricated microaccelerometer($\mu$XL). The $\mu$XL has received much commercial attraction, but its performance is generally limited. To improve the open-loop performance, a feedback controller is designed and experimentally evaluated. The feedback controller is applied to the x/y-axis $\mu$XL fabricated by sacrificial bulk micromachining(SBM) process. Even though the resolution of the closed-loop system is slightly worse than open-loop system, the bandwidth, linearity, and bias stability are stability are significantly improved. The noise equivalent resolution of open-loop system is 0.615 mg and that of closed-loop system is 0.864 mg. The bandwidths of open-loop and closed-loop system are over 100Hz. The input range, non-linearity and bias stability are improved from $\pm10\;g\;to\;\pm18g$, from 11.1%FSO to 0.86%FSO, and from 0.221 mg to 0.128 mg by feedback control, respectively.
서진덕 ( Jin Deok Seo ),임교묵 ( Kyo Muk Lim ),고형호 ( Hyoung Ho Ko ) 한국센서학회 2012 센서학회지 Vol.21 No.3
This paper presents frequency response compensation technique, and a self-oscillation circuit for capacitive microresonator with the compensation technique using programmable capacitor array, to compensate for the frequency response distorted by parasitic capacitances, and to obtain stable oscillation condition. The parasitic capacitances between the actuation input port and capacitive output port distort the frequency response of the microresonator. The distorted non-ideal frequency response can be compensated using two programmable capacitor arrays, which are connected between anti-phased actuation input port and capacitive output port. The simulation model includes the whole microresonator system, which consists of mechanical structure, transimpedance amplifier with automatic gain control, actuation driver and compensation circuit. The compensation operation and oscillation output of the system is verified with the simulation results.