Compact bandpass filters using stepped impedance resonators

This paper presents a theoretical analysis of, and experimental results given by, stepped impedance (SI) resonators constructed and used as high-Q resonators in the UHF band. These results made it clear that the Q-factor is higher than conventional capacitor-loaded resonators. Three types of bandpass filters were designed and fabricated using the SI resonators. The filters mentioned in this paper show that excellent performance has been obtained.