A filter includes a filter frame and at least two resonators. A receiving space is formed in the filter frame. The at least two resonators are disposed in the receiving space and distributed along a signal transmission path. Adjacent resonators on the signal transmission path are coupled. Each resonator includes a body part and a bending part. One end of the body part is grounded. The bending part includes a head bending part and an end bending part, the head bending part being connected to the end bending part to form a resonator structure circulating in a counterclockwise or clockwise direction.

A filter includes a filter frame and at least two resonators. A receiving space is formed in the filter frame. The at least two resonators are disposed in the receiving space and distributed along a signal transmission path. Adjacent resonators on the signal transmission path are coupled. Each resonator includes a body part and a bending part. One end of the body part is grounded. The bending part includes a head bending part and an end bending part, the head bending part being connected to the end bending part to form a resonator structure circulating in a counterclockwise or clockwise direction.

The present disclosure relates to a triple-mode resonator, comprising: a main body made of a dielectric material and having a cuboid shape defining three orthogonal axes (x, y, z) substantially aligned with faces of the main body; and a conductive coating covering all of the main body except portions of the faces of the main body which defines at least one coupling aperture through which a signal can be coupled into and/or out of the main body, wherein the coupling aperture has a closed shape comprising a first and a second main edges extending along two of the axes respectively and a third main edge extending neither parallel nor perpendicular to the first and second main edges, the general shape and size and location of the coupling aperture is mainly determined by the first, second and third main edges, and the coupling aperture is configured in such a manner that desired three dominant resonance modes can be excited independently in the resonator by an input signal introduced therethrough.

System, apparatuses and methods are disclosed which relate to the use of substrate integrated waveguide technology in front-end modules. An example circuit card assembly for use as a cellular base station front-end is disclosed which includes at least one component printed circuit board (PCB) layer having front-end module hardware components and at least one filter PCB layer including at least one substrate integrated waveguide (SIW) filter.

System, apparatuses and methods are disclosed which relate to the use of substrate integrated waveguide technology in front-end modules. An example circuit card assembly for use as a cellular base station front-end is disclosed which includes at least one component printed circuit board (PCB) layer having front-end module hardware components and at least one filter PCB layer including at least one substrate integrated waveguide (SIW) filter.

A resonant cavity filter includes a housing having a resonator therein, and a tuning element including an elongated pin member having a conductive outer surface. The tuning element is mounted for insertion of the elongated pin member into an interior of the resonator. The conductive outer surface includes a contact portion by which the elongated pin member is secured in a desired position to adjust a frequency response of the resonant cavity filter, where the contact portion is free of threading.

A resonant cavity filter includes a housing having a resonator therein, and a tuning element including an elongated pin member having a conductive outer surface. The tuning element is mounted for insertion of the elongated pin member into an interior of the resonator. The conductive outer surface includes a contact portion by which the elongated pin member is secured in a desired position to adjust a frequency response of the resonant cavity filter, where the contact portion is free of threading.

A metallized dielectric waveguide filter includes first and second input/output ports and a dielectric block that has metallized top and bottom surfaces and metallized sidewalls. The dielectric block further includes a plurality of metallized openings that extend into the interior of the dielectric block, and these metallized openings divide the dielectric block into a plurality of resonator cavities. A first of the metallized openings extends at an oblique angle with respect to a first of the metallized outer sidewalls.

A metallized dielectric waveguide filter includes first and second input/output ports and a dielectric block that has metallized top and bottom surfaces and metallized sidewalls. The dielectric block further includes a plurality of metallized openings that extend into the interior of the dielectric block, and these metallized openings divide the dielectric block into a plurality of resonator cavities. A first of the metallized openings extends at an oblique angle with respect to a first of the metallized outer sidewalls.

A dual-band filtering switch based on a single quad-mode dielectric resonator (DR) includes: a first printed circuit board (PCB) provided thereon with an input terminal; a second PCB provided thereon with an output terminal; a shielding shell arranged between the first and second PCBs and enclosing a shielding cavity together with the first and second PCBs; and a single quad-mode DR arranged in the shielding cavity. The first and second PCBs each include a feeding layer, a dielectric layer, and a ground layer that are stacked in sequence. The feeding layers of the first and second PCBs each include a microstrip line and a switching circuitry connected to the microstrip line, and the feeding layer is in contact with a surface of the DR to realize a switching function of the filtering switch. The proposed filtering switch feature low loss transmission and high selectivity with dual-band operation, miniaturization with the fewest resonators and friendly-integration, simultaneously.