NOVEL WIDEBAND TUNABLE RESONATOR AND THE APPLICATION TO FREQUENCY-AGILE BANDPASS AND BANDSTOP FILTERS.

In this paper, a novel end-loaded resonator is investigated and applied to design tunable bandpass fillter (BPF) and bandstop fillter (BSF). The novelty of the resonator lies in that two varactors are added to the two ends of the resonator, and then its resonant frequency can be bi-directionally tuned. As a result, the theoretical frequency tuning range can be significantly extended to approximately double that of the conventional tunable resonator. For demonstration, the proposed resonator is applied to design tunable BPF and BSF. As expected, the tuning ranges are 52.4% and 53.5% for the BSF and BPF, respectively. Good agreements can be observed between the simulated and measured results. [ABSTRACT FROM AUTHOR]