For Full-Text PDF, please login, if you are a member of IEICE,|
or go to Pay Per View on menu list, if you are a nonmember of IEICE.
Location of Multiple Transmission Zeros by Tap-Coupling Technique for Bandpass Filters and Duplexers Using Short-Ended λ/2 Resonators
Kouji WADA Yoshiyuki AIHARA Tomohide KAMIYAMA Osamu HASHIMOTO
IEICE TRANSACTIONS on Electronics
Publication Date: 2003/12/01
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Recent Trends on Microwave and Millimeter Wave Application Technology)
short-ended λ/2 resonator, multiple transmission zeros, tap-coupling, bandpass filter, duplexer,
Full Text: PDF(983.9KB)>>
In this paper, the method of locating multiple transmission zeros by the tap-coupling technique is described for bandpass filters (BPFs), using short-ended λ/2 resonators and its application to a duplexer. First, the method of locating the transmission zero using the short-ended λ/2 resonators is examined with various excitation methods. We focus on four types of short-ended λ/2 resonators: the end-coupling type, tap-coupling type, capacitive tap-coupling type and inductive tap-coupling type. Secondly, the BPFs based on the basic characteristics of the respective resonators are proposed and designed on the basis of a general filter theory with narrow band approximation. Lastly, we propose and design new duplexers consisting of the proposed BPFs. The results lead to the conclusion that the basic characteristics of the short-ended λ/2 resonators are useful for realizing a BPF with multiple transmission zeros and a high-performance duplexer fabricated without increasing the number of elements.