An effective method for designing bandpass filters using λ/4 resonators for improving out-of-band characteristics

摘要

In this paper, we examine the basic characteristics of various A/4 resonators for improving out-of-band characteristics of ban dp ass filters (BPFs). In this study, 3-pole BPF is composed by combined resonators above and is designed by using the general filter theory. As a result, it has been verified that the skirt characteristics and the spurious responses of the BPFs using λ/4 resonators have improved more effectively than before.