本論文以多重耦合線為核心，並使用負載電容的變化調整頻率響應特性，藉此實現 新式多功能微波元件，以提升將射頻收發機前端電路整合度。 首先，本論文提出五線式多重耦合線實現可切換式帶通濾波器，利用外接電晶體達 到切換功能，並以砷化鎵積體電路實現，將單刀雙擲切換器與帶通濾波器整合於單一元 件中，電路面積僅為0.063λg×0.043λg。其次，運用多重耦合線設計平衡至非平衡轉換 功能帶通濾波器，進一步將單刀雙擲、帶通濾波器與平衡至非平衡轉換器整合，並以砷 化鎵積體電路實現，電路面積僅為0.094λg×0.047λg。最後，運用濾波器可自由設計匹 配阻抗之特性，利用濾波器設計低雜訊放大器的輸入端與輸出端匹配網路，有效地將單 刀單擲切換器、帶通濾波器、低雜訊放大器、平衡至非平衡轉換器整合至單一元件內， 不僅縮小電路面積，也減小各級分開設計串接時所造成不匹配之損耗。 本論文所提出的新式多功能微波元件，以濾波器為基礎，並運用多重耦合線進一步 延伸整合射頻前端多種功能元件，具有簡潔的設計流程與公式，可有效的縮小射頻收發 機面積、成本與設計時間。 In this study, new multi-functional microwave components are achieved based on multicoupled-line with loaded capacitors to enhance integration of RF front-end circuit. First of all, five-line coupled-line is used to realize switchable bandpass filter. Besides using external connected transistors to obtain switch capability, the circuits are implemented by using the GaAs pHEMT process to achieve very compact size. In this way, single-pole-double-throw (SPDT) switch and bandpass filter are combined into single element whose size is only 0.063λg×0.043λg. Second, we use mutlicoupled lines to design balun bandpass filter integrated with SPDT switch. The proposed circuit is also implemented in GaAs pHEMT process and the circuit size is only 0.094λg×0.047λg. Finally, use the impedance matching capability of filter to design Low Noise Amplifier (LNA) whose input and output matching network can effectively integrate single-pole-single-throw (SPST) switch, bandpass filter, and balun. In this way, the circuit size can be largely minimized and the mismatch loss resulted from cascade connection can also be reduced. The proposed multifunctional microwave component is based on conventional microwave filter design, and mutlicoupled lines are used to achieve the integration of multiple function blacks in a RF front-end. Simple design procedure and equations are presented in this study. Hence, RF transceiver size and cost can be minimized, and shorten designing time can be achieved.
