摘要
傳統的平衡與不平衡轉換器(Balun)與循環器都是三端元件，在射頻前端電路中扮演著重要的腳色。主動式Balun有別於被動式Balun能提供額外的增益，但在應用上主動式Balun卻因為電路架構使的輸出兩端的隔離度通常不甚理想，因此通常需要在輸出端附加緩衝器來增加其隔離度，也因此增加了額外的功耗。本論文提出了橋式T型網路來代替緩衝器的功能與相位校正技巧，以降低功耗、提高隔離度與降低相位誤差。在循環器應用方面，循環器則是實現用單一天線同時做收跟發的元件，相較於一般的開關切換電路以非同步的方式快速切換來實現單一天線收發有所不同。由於被動式循環器是使用磁性材料，其體積龐大，無法實現在積體電路上，因此需要使其改變成主動的方式。本篇論文設計了兩種不同的主動式循環器，一個是使用既有的類循環器接成環形以達到循環器的效果，另一個則是使用橋式T型網路來實現一個循環器。 全論文在第二章討論並實現一個低相位誤差與高隔離度之主動式Balun，在第三章則是使用既有電路與全新的設計去實現兩種不同的循環器。全部電路都是使用台積電0.18um 1P6M CMOS製程上做設計。
並列摘要
Conventional baluns and circulators are both 3-port components, and play an important role in the RF front-end circuit. In the application of active baluns, active baluns unlike passive baluns cause losses, they can provide extra gain. However, the isolation of active balun is poor due to the structure of the circuit and parasites. Therefore, they usually needs additional buffers to enhance the isolation, and then consume more power. In the application of circulators, a circulator is the component that can do transmit and receive simultaneously by single antenna, and it is generally differ from the conventional switch circuits, which do transmit and receive by rapid switching. Owing to the passive circulator which forms huge volume is manufactured by ferrite; it is difficult to be fabricated on the integrated circuit. From this point, transform the passive circulator to be active one is necessary. In this thesis, an active balun and two different active circulators are designed. The active balun utilizes the bridge-T network to replaces the function of buffer and it also reduce the power consumption and enhance the isolation. Furthermore, for low phase error, the phase correction technique is also needed in the active balun. The active circulators utilize the identical unit cell by connecting in the ring-type configuration, one of the active circulators utilizes the existing quasi-circulator as a unit cell, and the other one utilizes the bridge-T network. The two configurations are all work well in achieving the 3-port circulator. Chapter 2 presents the implementation and discussion of proposed active balun, and chapter3 presents the proposed active circulators. All the circuits are fabricated in TSMC 0.18um CMOS 1P6M process.