| 摘要: | 為了節省行動裝置中寶貴的電路面積並減少各元件間的連線與失配損耗，本研究提出四種基於電容負載多重耦合線結構的微型化可切換式帶通濾波器，以整合射頻開關與頻帶選擇濾波器。運用圖像轉換法與植入損耗法，可大幅簡化以多重耦合線組成之單刀單擲可切換式帶通濾波器的分析與合成方法。隨後並提出一個微型單刀雙擲可切換式帶通濾波器。藉由運用J型轉阻器來取代過去聯結兩訊號路徑共同接點處之四分之一波長阻抗轉換器，可使得電路尺寸大幅減小，並且可使設計方法簡化。經驗證可知，此電路在導通時具有低植入損耗，在閉止時具有良好的隔離度，且具有高線性度等特性。第二個提出的電路為其輸出埠可為單端或差動輸出的單刀雙擲可切換式帶通濾波器，為前一個單刀雙擲可切換式帶通濾波器的延伸。此時，所提出的多功能電路，可有效整合一單頻收發機中的單刀雙擲射頻開關，發射路徑濾波器，接收路徑濾波器，與平衡-非平衡轉換器。並且此電路仍具有小尺寸，低導通態植入損耗，良好的閉止態隔離度，極佳的線性度與平衡特性。接著提出單刀雙擲可切換式雙工器。其整合了單刀雙擲射頻開關與雙工器，而其中每一個訊號路徑可以單獨使用前述的單刀單擲可切換式帶通濾波器(即植入損耗法)來設計。此外，只要透過對第一個共用諧振器做改良，即可在不增加額外電路元件下，使兩組單刀雙擲可切換式雙工器並聯，而成為一個單刀四擲可切換式四工器。本研究所提出的各種具電容負載下多重耦合線可切換式帶通濾波器，經實做驗證並與其他文獻比較，確實可具有尺寸微小化與其它優良的電路特性，且將可適用於多頻多模射頻前端電路中。;In order to save the valuable circuit size and reduce the mismatching loss on the interconnection between components for mobile device application, in this study, four switchable bandpass filters based on multicoupled line are proposed for integration of the functions of RF switch and band selection filters. By utilizing the graph transformation technique and insertion loss method, the analysis and synthesis procedure of a fundamental single-pole-single-throw (SPST) switchable bandpass filter (BPF) are much simplified. Then, a compact single-pole-double-throw (SPDT) switchable BPF is proposed. By replacing the quarter-wavelength impedance transformer at the common junction in conventional designs with a J-inverter, the circuit size is largely reduced and the design procedure can be much simplified. In addition, low insertion loss in the on state, good isolation in the off state, and good linearity are obtained. The second design is an extension of the proposed SPDT switchable BPF, in which the output port can be designed as either single-ended or differential ones. The proposed multi-functional circuit can thus effectively integrate the SPDT RF switch, TX/RX BPFs, and balun of a single-band transceiver in one single circuit. In addition, compact circuit size, low insertion loss in the on state, good isolation in the off state; excellent linearity and good balanced performance are achieved. Then, the proposed SPDT switchable diplexer integrates the functions of SPDT RF switch and diplexer, and each signal path can be independently synthesized using the insertion loss method. In addition, by a simple modification to the common resonator, a SPQT switchable quadplexer can be achieved by the connection of two proposed SPDT switchable diplexers. Low loss, compact size, good selectivity, and high linearity are also achieved. All the proposed switchable bandpass filters based on multicoupled line feature compact size and good performances, and they can be good solutions for multi-mode, multi-band RF front end application. |
