Design of Miniaturized Bandpass Filter Using Modified Coaxial Cavity Resonator

This paper presents a novel modified coaxial cavity resonator and its application to bandpass filters (BPF) with compact size. Unlike the conventional coaxial cavity resonator, the proposed resonator is made up of multi-metal-slices-loaded on the inner coaxial conductor within a single rectangle cavity. The technique with multi-metal-slices is applied to enhance the self-inductance and self-capacitance of the coaxial cavity resonator which leads to size reduction. Based on the research of position and size for the loading multi-metal-slices, an efficient way to load is proposed, Compared to the conventional coaxial cavity resonator, the central frequency can be reduced. Finally, a simulation example of BPF using this technique is presented to validate this attractive design concept.