以單增益元件設計之電流式多功濾波器與正交振盪器

Current-Mode Multifunction Filter and Quadrature Oscillator Using Unit Gain Cells

唐漢威(Han-Wei Tang)

指導教授 ： 洪君維

中原大學/工學院/電子工程研究所/碩士(2006年)

https://doi.org/10.6840/cycu200600161

摘要

本論文提出使用單增益元件(Unity-gain Cell)設計的電流式多功濾波器(Current-Mode Multifunction Filter)和正交振盪器(Quadrature Oscillator)。
首先，我們提出一個電流式多功二階濾波器，使用兩個單增益電流隨耦器(Current Followers；CFs)，兩個單增益電壓隨耦器(Voltage Followers；VFs)，四個電阻和兩個接地電容，能同時實現高通、帶通、低通濾波器。此電路有以下特點：(1)藉由連結適當的電流輸出節點，得到帶拒、全通和另一個高通濾波器；(2)除了全通響應，不需要阻抗匹配；(3)極點頻率與品質係數可正交調整；(4)有低的主、被動元件敏感度；(5)只使用接地電容，利於積體化的實現。
其次，將提出的電流式多功濾波器電路架構，透過輸出電壓信號的回授且藉由電阻做電壓轉電流的轉換，可實現一個新的正交振盪器。所提出的正交振盪器有以下特點：(1)從同一個電路同時得到電壓式與電流式正交信號；(2)振盪條件和振盪頻率可藉由不同電阻獨立調整；(3)有低的主、被動元件敏感度；(4)僅使用接地電容。
最後，我們從實驗的結果證明本論文所提出之電路的可行性。

關鍵字

單增益元件 ； 正交振盪器 ； 多功濾波器

並列摘要

In this thesis, a new current-mode multifunction filters and quadrature oscillator using unit gain cells are presented.

First, we present a current-mode multifunction filters, using two unity-gain current followers, two unity-gain voltage followers, four resistors and two grounded capacitors, for realizing current-mode highpass, bandpass and lowpass filters, simultaneously. The proposed circuit configuration offers the following features: (1) by connecting appropriate output current nodes, the notch, allpass and another highpass filters can be obtained; (2) no requirements for components matching conditions except for the allpass response; (3) orthogonally controllable of resonance angular frequency and quality factor; (4) the active and passive sensitivities are all low; (5) the use of only grounded capacitors that is ideal for integrated circuit implementation.

Secondly, from the proposed circuit configuration of current-mode multifunction filters, by feedback the output voltage signal via a resistor as voltage to current converter. A new quadrature oscillator circuit can be obtained. The proposed quadrature oscillator offers the following features: (1) both voltage-mode and current-mode quadrature signals can be simultaneously obtained from the same circuit configuration; (2) the oscillation condition and oscillation frequency are independently controllable through different resistors; (3) the active and passive sensitivities are all low; (4) employs only grounded capacitors.

In the end, experimental results are given to demonstrate the feasibility of the proposed circuits.

並列關鍵字

Unit Gain Cells ； Multifunction Filter ； Quadrature Oscillator

參考文獻

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[7] J.-J. CHEN, C.-C. CHEN, H.-W. TSAO and S.-I. LIU, “Current-mode oscillators using single current follower,” Electronics Letters, Vol. 27, pp. 2056-2059, 1991.