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リ ネイ
LI NING
李 寧 所属 工学部 電気電子工学科 職種 助教 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2008/06 |
| 形態種別 | 学術論文 |
| 査読 | 査読あり |
| 標題 | Analysis of CMOS Transconductance Amplifiers for Sampling Mixers |
| 執筆形態 | 共著 |
| 掲載誌名 | IEICE Transaction on Electronics |
| 掲載区分 | 国内 |
| 概要 | In this paper the transfer function of a system with windowed current integration is discussed. This kind of integration is usually used in a sampling mixer and the current is generated by a transconductance amplifier (TA). The parasitic capacitance (Cp) and the output resistance of the TA (Ro,TA) before the sampling mixer heavily affect theperformance. Calculations based on a model including the parasitic capacitance and the output esistanceof the TA is carried out. Calculationresults show that due to the parasitic capacitance, a notch at thesampling frequency appears, which is very harmful because it causes the gain near the sampling frequency to decrease greatly. The output resistance of the TA makes the depth of the notches shallow and decreases the gain near the sampling frequency.To suppress the effect of Cp and Ro,TA, an operational amplifier is introduced in parallel with the sampling capacitance (Cs). Simulationresults show that there is a 17dB gain increase while Cs is 1pF, gm is 9mS, N is 8 with a clock rate of 800MHz.
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