Disclosed are embodiments of synthetic garnet materials for use in radiofrequency applications. In some embodiments, increased amounts of bismuth can be added into specific sites in the crystal structure of the synthetic garnet in order to boost certain properties, such as the dielectric constant and magnetization. Accordingly, embodiments of the disclosed materials can be used in high frequency applications, such as in base station antennas.

Disclosed herein is a radio frequency filter having a notch structure. The radio frequency filter includes a hollow housing having a plurality of partition walls defining a plurality of cavities and an open surface formed on one side, a cover configured to shield the open surface of the housing, a plurality of resonance elements positioned in the cavities of the housing, a coupling substrate arranged to cross a partition wall between at least two of the plurality of resonance elements, and a tuning screw inserted into the housing through the cover. The partition wall crossed by the coupling substrate includes a support window formed to have a first depth from the open surface, the coupling substrate being arranged through the support window, and a tuning window formed to have a second depth greater than the first depth from the open surface, the tuning screw being inserted into the tuning window.

Resonant cavity filters include a conductive housing having a floor. A dielectric resonator is mounted to extend upwardly from the floor. The dielectric resonator has a cylindrical body with a longitudinal bore that defines an inner sidewall. The longitudinal bore has a variable transverse cross-sectional area. A threaded dielectric fastener is at least partially inserted within the longitudinal bore of the cylindrical body.

Resonant cavity filters include a conductive housing having a floor. A dielectric resonator is mounted to extend upwardly from the floor. The dielectric resonator has a cylindrical body with a longitudinal bore that defines an inner sidewall. The longitudinal bore has a variable transverse cross-sectional area. A threaded dielectric fastener is at least partially inserted within the longitudinal bore of the cylindrical body. The dielectric resonator may have a protrusion that extends inwardly from the inner sidewall.

A resonating structure and a dielectric filter having the same are disclosed. The resonating structure comprises a body, at least one set of negative coupling holes, and a conductive material layer. The body is made of a solid dielectric material and comprises at least two resonators. The negative coupling holes are formed at a connection between two adjacent resonators. Each set of negative coupling holes comprises a first blind hole and a second blind hole disposed on two opposite surfaces of the body respectively. The first blind hole and the second blind hole are offset from each other in a plane perpendicular to a direction along which the first or second blind hole is dug. The conductive material layer covers surfaces of the body and surfaces of the first blind hole and the second blind hole.

A method of making a dielectric, Dk, electromagnetic, EM, structure, includes: providing a first mold portion comprising substantially identical ones of a first plurality of recesses arranged in an array; filling the first plurality of recesses with a curable first Dk composition having a first average dielectric constant greater than that of air after full cure; placing a substrate on top of and across multiple ones of the first plurality of recesses filled with the first Dk composition, and at least partially curing the curable first Dk composition; and, removing the substrate with the at least partially cured first Dk composition from the first mold portion, resulting in an assembly having the substrate and a plurality of Dk forms including the at least partially cured first Dk composition, each of the plurality of Dk forms having a three dimensional, 3D, shape defined by corresponding ones of the first plurality of recesses.

The present invention is a tunable bandpass filter to provide a constant absolute bandwidth across a tuning range, comprising of a pair of resonators to determine a filter center frequency, each said resonator has a rectangular waveguide cavity, wherein said filter center frequency depends on the dimensions of said rectangular waveguide cavity; a pair of side walls attached to said pair of resonators to form a filter housing; a tuning element movably attached to at least one of said pair of side walls and extending in said filter housing and movable orthogonally to said pair of resonators, and wherein said dimensions of said rectangular waveguide cavity change by moving said tuning element, thereby said filter center frequency is changed.

Example dielectric filters, transceiver devices, and base stations are described. One example dielectric filter includes a dielectric block whose surface is covered with a metal layer, where the dielectric block includes at least two resonant cavities. The dielectric block is provided with a via hole, the via hole is located between two adjacent resonant cavities, and an inner wall of the via hole is covered with a metal layer. A first partition ring is disposed on the surface of the dielectric block and is surrounding at least one opening of the via hole, and the dielectric block is exposed in an area enclosed by an inner edge of the first partition ring and an outer edge of the first partition ring.

The invention relates to a method of manufacturing a dielectric filter. The method comprises the steps of: (a) preparing a ceramic substrate; (b) applying a conductive paste on the ceramic substrate, wherein the conductive paste comprises, (i) 100 parts by weight of a conductive powder, (ii) 0.1 to 10.0 parts by weight of a glass frit comprising silicon oxide, boron oxide, aluminum oxide and an alkaline metal oxide, and (iii) an organic vehicle; and (c) firing the applied conductive paste.

This application provides a dielectric resonator, including a dielectric body disposed in a hollow conductive housing, where the dielectric body includes a first end face and a second end face that are disposed opposite to each other and a circumferential surface connected between the first end face and the second end face. The first end face is provided with a first groove, the second end face is provided with a second groove, the first end face and the second end face are in contact with an inner wall of the conductive housing, and extension directions of the first groove and the second groove are different. This application further provides a filter. This application can implement single-sided installation of the dielectric resonator, so that an objective of miniaturization is achieved and assembly becomes easy. In addition, coupling between resonance modes can be enhanced because the extension directions of the first groove and the second groove are different.