電流式類比信號處理系統有許多具潛力的優異點，包括較大的頻寬、較低的電路複雜度、較寬的動態範圍、較快的操作速度。由於文獻上可取得眾多連續時間電壓式電路，電路轉換技術因而受到不少的注意，因為藉由轉換技術可由現有電路直接產生新的電路。在這些轉換技術中，以伴隨轉換(Adjoint Transformation)與反函數轉換(Inverse Transformation)最為普遍，伴隨轉換適用於單輸入單輸出系統，可將電壓式(電流式)電路轉換得電流式(電壓式)電路，由於多輸入/多輸出系統具較大的應用方便性，我們擴大伴隨轉換的使用，將其應用在多輸入/多輸出系統上。另外，藉由反函數轉換，我們可以獲得原系統的反函數系統，這種技術可應用在通訊、控制、量測系統的需求上。為減少經反函數轉換所得的反函數系統的電路複雜度，本文中亦探討如何將反函數轉換應用在其他的特異元件(Pathological Element)上，我們也定義了新的四端主動元件以實現反函數系統中的四端特異元件，並合併使用伴隨轉換與反函數轉換以獲得電流式反函數濾波器，並就其串接特性作深入探討。除了利用電路轉換合成技術產出電路外，我們也直接設計一些獨特的振盪器與濾波器。所提出的濾波器電路是利用雙輸出電流傳輸器(Current Conveyor)當主動元件來設計，具備多功能、可串接、易積體化、低主動與被動靈敏度、構造簡單等特點。最後，為設計高階濾波器與振盪器，我們探討了阻納模擬電路的設計，並探究如何有系統地合成各種阻納模擬。論文中提出的所有新技術，都經由電腦模擬器模擬或實驗量測驗證過，相信所提出的技術，提供了類比信號處理電路上新的設計領域與可行之道，在高效能電流式主動元件與電路積體化研製的更進一步研究，則為未來將探討的主題。 The implementation of analog signal processing systems in the current domain offers the potential advantages of higher bandwidth capability, less circuit complexity, wider dynamic range, and higher operating speed. Consequently, current-mode approach has been accepted as an alternative mean besides the traditional voltage-mode circuits.Owing to the availability of wealthy voltage-mode continuous time circuits in the literature, the techniques of transformation have received considerable attention for their convenience in generating new circuits from present well-developed voltage-mode ones. Among the transformation techniques, adjoint transformation and inverse transformation are two of the most popular ones. Adjoint transformation is a general method to derive current-mode filters from voltage-based filters for the single-input-single-output systems. We extend the application of adjoint transformation in designing multi-input/multi-output filters due to the growing interest in designing multi-input or multi-output systems. Inverse transformation is also a general method for obtaining the inverse system in the case of continuous time circuit for applications in communication, control and instrumentation systems. For reducing the circuit complexity of some derived inverse systems, the application of other pathological elements in the inverse transformation has been investigated in this dissertation. New defined active building blocks are employed for realizing the four-terminal pathological elements in the derived inverse circuits and adjoint circuits. Moreover, the combination of adjoint and inverse transformations is presented that can be used to obtain current-mode inverse filters, along with an investigation of the cascadability of the derived filters. In addition to the synthesis approach in virtue of transformations, direct design of oscillators and filters are presented. Finally, immittance simulated circuits have been studied for the designs of higher-order active filters and sinusoidal oscillators. A systematic approach to the synthesis of various immittances has been explored. All the new techniques proposed in this dissertation have been verified by computer simulations or experimental measurements. It is believed that the proposed techniques offer promising approaches and new scope for the design of analog signal processing circuits. Further research on high-performance implementation of the current-mode active devices and circuits in monolithic technology is the subject of future study.
