Browsing by Author "Lin, HW"

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An accurate RF CMOS gate resistance model compatible with HSPICE
(2004)
Lin, HW
;
Chung, SS
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Wong, SC
;
Huang, GW
;
電子工程學系及電子研究所
Two important models, which are crucial to the RF CMOS, are the gate resistance and substrate resistance. Both are closely related to the development of accurate device and/or circuit models, such as noise. From the experimental observations, we found that the gate resistance depends largely on the bias and temperature. It will greatly impact the device performance at high frequency. For the first time, a simple and analytical physical-based gate resistance model is developed in this paper and has been implemented in Spice. The gate resistance is modeled by a parallel interconnection of the intrinsic gate resistance and a resistance coupled from the channel. The Spice simulation result of this model is more accurate than that of using a constant R-g model. A constant Rg model will overestimate the value of Y-11. While, in contrast, the proposed nonlinear gate resistance model with both bias and frequency dependent feature can achieve very good accuracy.
The algorithms of the cross-coupled precompensation method for generating the involute-type scrolls
(1999-03-01)
Chin, JH
;
Lin, HW
;
機械工程學系
;
Department of Mechanical Engineering
Cross-coupled precompensation method (CCPM) has been proven efficient in tracking nonlinear spatial curves. Ir requires a path generating algorithm derived from the mathematical equation of the target curve. This paper discussed the time base transform of target curve from a parametric form. The time based path generating algorithm for the extended involute scroll was then proposed. A comparison among three kinds of tool path generating algorithms were performed. The proposed path algorithms, along with other two algorithms, were implemented and tracked by Sour different control schemes. US (uncoupled-unprecompensated system), CCS (cross-coupled system), PPM (path precompensation method), and cross-coupled precompensation method (CCPM). The proposed path algorithm for extended involute scroll provided the best accuracy. The proposed algorithm tracked by CCPM achieved the most precise profile especially at high feedrates.