本論文中，我們利用標準的數位CMOS製程技術去實現低電壓平方根領域濾波器，這些濾波器包含低通、高通、帶通、雙二次濾波器。根據狀態空間方法以及MOSFET平方定律可由轉移函數推出相對應的KCL節點方程式，因此濾波器可以利用這種具有系統性以及可合成性的程序來建立。建構濾波器最主要的元件是電流鏡以及藉由操作在次臨界區電壓平均電路來設計的平方根電路。
　　我們藉由HSPICE來驗證所設計出來的濾波器。模擬的結果顯示濾波器之正確性，本設計的供應電壓為一伏特而功率消耗小於1.1 mW，3dB頻率具可調性，總諧波失真小於2%。

　　In this thesis, low-voltage square-root domain filters have been designed including low pass, band pass and biquad filters in standard digital CMOS technology. According to state-space approach and MOSFET square law, the KCL current equations can be derived from transfer function. Therefore the filters can easily be constructed with a systematic and synthesizable procedure. The main blocks of the filters are current mirrors and square-root circuits fulfilled by the voltage averaging circuits operated in subthreshold region.
　　The filters have been simulated by HSPICE to verify the functionality. The simulation results show the filters perform well. The supply voltage of the filters is 1 V and the power consumption is less than 1.1 mW. The 3dB frequency is tunable, and the THD is less than 2%.

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