本論文提出了五種設計方法來實現多頻帶的帶通濾波器，依序分別為雙頻之柴比雪夫帶通濾波器、三頻段之多模態寬頻帶通濾波器、具相鄰頻段之雙頻帶通濾波器、兼具窄頻與寬頻應用之雙頻帶通濾波器和多功能性四頻段帶通濾波器。其中，雙頻之柴比雪夫帶通濾波器具有彈性的頻帶控制與佈局簡單等特性，並透過分佈式耦合技術，使得各頻段可以獨立的設計；三頻段之多模態寬頻帶通濾波器乃基於一個多模態共振器所形成的超寬頻帶，並透過傳輸零點的設計將之分成三個通帶；相鄰頻段之雙頻帶通濾波器是利用共振器交錯耦合的方式來達成分裂式的通帶；。兼具窄頻與寬頻應用之雙頻帶通濾波器是利用連接線耦合結構與雙模態共振器來分別實現寬頻與窄頻通帶；多功能性四頻段帶通濾波器是利用分佈式耦合技術來整合上述的電路，以實現寬頻、窄頻、相鄰通帶與非相鄰通帶的特性。 以上所有電路皆以微帶線結構來進行設計並實作，其模擬與量測結果皆有良好的一致性，驗證了所提出的設計方法是有效且可行的。 This thesis proposes five circuit designs including a dual-band Chebyshev bandpass filter (BPF), a multi-mode triple-wideband BPF, a dual-band BPF with close band spacing, a dual-band BPF with narrow-band and wideband application, and a multifunctional quad-band BPF. The dual-band Chebyshev BPF has the advantages of simple layout and flexible band control. Meanwhile, by employing the distributed coupling technique, each passband can be design individually; The triple-wideband BPF is constructed by the combination of a single stepped-impedance stub-loaded resonator (SISLR), inter-digital coupled-lines, and open-ended stepped-impedance stubs. A triple wide-passband response is achieved by creating extra transmission zeros to split the single ultra-wide passband into three; The dual-band BPF with close band spacing was designed by introducing the cross coupling between non-adjacent resonators. The dual-band frequency response is achieved by creating a stopband inside a virtual wide passband; The dual-band BPF with narrow-band and wideband application was designed by integrating a wideband BPF based on the connecting admittance invertors and a narrow-band BPF based on a dual-mode stub-loaded resonator; The multifunctional quad-band BPF was designed by using the distributed coupling technique to integrate the aforementioned circuit so as to realize the property of wideband, narrow-band, close band spacing, and wide band spacing. For demonstration, all circuits mentioned above were designed and fabricated with microstrip technology. Moreover, good agreements are achieved between simulations and measurements.
