射頻與中頻之帶通濾波器研究

Abstract

本論文中發表了一系列新型的射頻及中頻的帶通濾波器。第一種是利用末 端短路四分之一波長微帶線式的共振器及微帶線指狀組合式電容器作為藕 合元件，研製在S-頻帶相對頻寬3%及15.4%的帶通濾汲器。第二種則是利 用新型的共平面式共振器所研製的一個在ISM(工業-科學-醫學)頻帶2.4 GHz-2.4835GHz平面式帶通濾波器。最後一種則是很特殊的可調頻寬而且 中心頻率固定在480MHz的帶通濾波器。可調頻寬的範圍是 26MHz到52MHz 。這些濾波器測量的結果與Touchstone和Microwave Ex- plorer軟體模擬 結果非常吻合，而且都可以用光照印刷電路版的技術來製造，更可以被應 用在無線及衛星通訊收發機上。 In this thesis, a new class of RF and IF bandpass filters (BPFs) are presented. First, S-band planar BPFs with a relative 3% and 15.4% bandwidth are realized using chort-circuited quarter- wavelength microstrip resonators and microstrip inter- digital capacitors as coupling elements. Secondly, an ISM ( Industrial- Scientific-Medical) band 2.4-2.4835GHz planar BPF is realized using new coplanar resonators. Finally, a novel variable bandwidth BPF centered at 480MHz is presented. The adjustable bandwidth is 26MHz to 52MHz. All of the filters can be fabricated with photolithographic techniques. The measured results agree favorably with the theoretical values obtained by Touchstone and Microwave Explorer. These filters approaches prove to be suitable for wireless and communicaion transceiver applications.