Circular Monoblock Dielectric Resonator Filter Based On 60-Degree Sectorial Resonators

A circular monoblock dielectric resonator filter based on 60-degree sectorial resonators is proposed in this study. This filter is formed of six 60-defree sectorial resonator. A blind hole is drilled on the top of each 60-degree sectorial resonator to modulate the resonant frequency. Magnetic coupling between each resonator is implemented by using metalized through holes instead of traditional partitioning walls, which can be simple in structure. Electrical coupling is realized by a metalized blind hole to realize dispersive coupling, which fulfils the function of diagonal cross coupling to generate two transmission zeros. A partitioning through hole is set at the center of the whole cavity to suppress the unnecessary cross coupling. The structure of the proposed filter is discussed and simulated. The simulated results show that the designed filter has a fractional bandwidth of 7.8
^%
at 3.6GHz with two out-of-band transmission zeros at 3.38 and 3.74 GHz, and the insertion loss and return loss agree well with the theoretical results.