High-Order Dual-Band Bandpass Filter with Independently Controllable Frequencies and Bandwidths

A multi-stub-loaded resonator is presented in this paper. The resonators can be conveniently applied to design high-order dual-band bandpass filters (BPFs). Base on the analysis of the resonator, the first two even-mode resonant frequencies are controlled independently by the lengths of the loaded stubs. Two high-order dual-band BPFs using the first two even-mode resonant frequencies of the multi-stub-loaded resonators are proposed. The bandwidth of each passband can be adjusted independently by the coupling strength of the adjacent resonators. This paper deals with the analysis and design of the proposed high-order dual-band BPFs as well as the experimental validations of the predicted dual-band performance.