Abstract: A resonator, a filter, a duplexer, and a multiplexer are disclosed. In an embodiment a resonator includes a resonant cavity casing having a resonant cavity and an open end, a cover covering the open end and being connected to the resonant cavity casing and a resonance tube located inside the resonant cavity. The resonator further includes a tuning rod disposed inside the resonance tube and a dielectric material located in the resonant cavity, wherein the dielectric material is located in a capacitance area formed between a top of the resonance tube and the cover, wherein the tuning rod is rotatable relative to the dielectric material, and wherein surfaces of the tuning rod and the dielectric material face each other and comprise non-circular structures so that an overlapping of the surfaces is changeable to adjust a frequency when the tuning rod is rotated relative to the dielectric material.

Abstract: A resonator, a filter, a duplexer, a multiplexer, and a communications device that use the resonator, where the resonator includes a resonant cavity body that has a resonant cavity and an open end, a cover that covers the open end and that is connected to the resonant cavity body, and a resonant tube that is located inside the resonant cavity, a medium material is padded in a capacitor area in the resonant cavity and whose dielectric constant is greater than 1, the resonant tube includes a resonant tube body and an elastic structure that is combined with the resonant tube body, and the elastic structure provides elastic pressure in an axial direction of the resonant tube where the resonator may reduce a conductor loss and improve a power capacity, and has relatively low costs.

Abstract: A resonator, a filter, a duplexer, a multiplexer, and a communications device that use the resonator, where the resonator includes a resonant cavity body that has a resonant cavity and an open end, a cover that covers the open end and that is connected to the resonant cavity body, and a resonant tube that is located inside the resonant cavity, a medium material is padded in a capacitor area in the resonant cavity and whose dielectric constant is greater than 1, the resonant tube includes a resonant tube body and an elastic structure that is combined with the resonant tube body, and the elastic structure provides elastic pressure in an axial direction of the resonant tube where the resonator may reduce a conductor loss and improve a power capacity, and has relatively low costs.

Abstract: A resonator, a filter, a duplexer, and a multiplexer are disclosed. In an embodiment a resonator includes a resonant cavity casing having a resonant cavity and an open end, a cover covering the open end and being connected to the resonant cavity casing and a resonance tube located inside the resonant cavity. The resonator further includes a tuning rod disposed inside the resonance tube and a dielectric material located in the resonant cavity, wherein the dielectric material is located in a capacitance area formed between a top of the resonance tube and the cover, wherein the tuning rod is rotatable relative to the dielectric material, and wherein surfaces of the tuning rod and the dielectric material face each other and comprise non-circular structures so that an overlapping of the surfaces is changeable to adjust a frequency when the tuning rod is rotated relative to the dielectric material.