A multi-mode cavity filter, including two dielectric resonator bodies, the first incorporating a piece of dielectric material having a shape to support a first resonant mode and a second substantially degenerate resonant mode; the second also including a piece of dielectric material; the piece of dielectric material having a shape to support a first resonant mode; a layer of conductive material in contact with and covering both of the dielectric resonator bodies; an aperture in the layer at the interface of the first and second dielectric resonator bodies, for transferring signals from the second dielectric resonator body to the first, transferring signals from the first dielectric resonator body to the second and/or outputting signals from the first dielectric resonator body, the aperture being arranged for coupling signals to the first and second resonant modes in parallel, and/or coupling signals from the first and second resonant modes in parallel.

A quad-mode microwave or RF bandpass filter comprises a housing of a conductive material defining a cylindrical cavity and containing a cylindrical dielectric resonator defined by a parallel pair of face surfaces. The dielectric resonator is held within the housing between a pair of support plates of a dielectric material. Internal coupling elements are provided above and/or below the dielectric resonator for coupling between resonating modes. Further mode coupling elements are protruding into the housing.

An apparatus includes a filter. The filter includes a metal structure forming a cavity and includes a ceramic block, which is suspended in the cavity. The ceramic block has two removed portions, the removed portions removed from two opposing sides of the ceramic block. The ceramic block further has one or more slots that that span a region of ceramic between the two removed portions and connects chambers formed by the two regions with chambers formed by the one or more slots, wherein a combined structure of the ceramic block, cavity, and metal structure supports multiple fundamental TM modes and one fundamental TE mode. The filter comprises multiple coupling structures to couple radio frequency signals into and out of the filter. The apparatus may include multi-cavity filters including one and typically multiple ones of the filters.

A mixed-mode dielectric waveguide filter is provided. The mixed-mode dielectric waveguide filter includes a first multi-mode resonant cavity having at least two resonant modes, and a pair of first single-mode resonant cavities, wherein the pair of first single-mode resonant cavities correspond to the first multi-mode resonant cavity, and are directly coupled to a respective resonant mode of the first multi-mode resonant cavity to form a series topology with the first multi-mode resonant cavity, and wherein a parallel topology is formed between resonant modes of the first multi-mode resonant cavity.

A band pass filter suitable for varying the center frequency of the passband and a method for controlling the band pass filter are provided. A band pass filter of the present invention includes: two TE01-mode dielectric resonators (10) and (20) disposed so as to oppose to each other; and a housing (30) made of metal enclosing the two dielectric resonators (10) and (20). An opposing interval between two dielectric resonators (10) and (20) is variable.

An RF filter includes: an electrical conductor defining an outer sphere; a dielectric material defining an inner sphere disposed within the conductor outer sphere; and at least a first electrical probe and a second electrical probe. Each probe extends through the conductor and is electrically insulated from it. A spherical shape of one or both of the inner and outer spheres is interrupted by: a) a first localized discontinuity in said spherical shape disposed along a first axis passing through a geometric center of the one or both of the inner and outer spheres; and b) a second localized discontinuity in said sphere form disposed along a second axis passing through the geometric center, the second axis perpendicular to the first axis. There can be more than these two discontinuities, implemented as chamfers, tuning screws, and the like. Series and parallel coupling of the spheres is detailed.

A multi-mode cavity filter, including at least one dielectric resonator body incorporating a piece of dielectric material having a shape to support first resonant mode and a second substantially degenerate resonant mode; excitation device(s) for at least one of: establishing an electromagnetic field external to, but immediately adjacent to, a face of the dielectric resonator body or for extracting energy from an electromagnetic field located external to, but immediately adjacent to, a face of the dielectric resonator body, a layer of conductive material in contact with and covering the dielectric resonator body on the face of the dielectric resonator body: at least one aperture in the layer of conductive material for inputting signals to the dielectric resonator body and/or outputting signals from the dielectric resonator body, wherein the excitation device is located, in at least two dimensions, at an electrical center of the face of the dielectric resonator body.

A triple-band bandpass filter with at least one cavity resonator. Each cavity resonator has the same three orthogonal resonances modes corresponding to three unique resonance frequencies. The three unique resonance frequencies define the passbands of the filter. The filter has an input probe coupled to an input cavity resonator. The filter has an output probe coupled to an output cavity resonator. The input and output probes are shaped to concurrently couple signal waveforms in each of the resonance modes. Coupling probes that can be used as input or output probes are also provided. An inter-cavity coupling operable to concurrently transmit signal waveforms in each of the resonance modes is also provided. The inter-cavity coupling can be used to transmit signals between adjacent cavity resonators in the filter.

An apparatus includes a filtenna. The filtenna includes a block having a waveguide formed therein, and having first and second ends, wherein the first end is closed and the second end radiates to free space. The filtenna also includes multiple patch elements suspended within the waveguide, ordered from a first patch element at the first end of the waveguide to a final patch element at the second end of the waveguide. The filtenna further includes one or more ports at the first end of the waveguide. Each of the one or more ports is electrically coupled to the first patch element, and is for coupling to a corresponding antenna polarization. A dual-polarized filtenna is possible, as are transmitters, receivers, base stations, and the like. An array of filtennas may be created and used, and the filtenna(s) may be used for transmission, reception, or both.

The present disclosure relates to a dielectric cavity resonator, comprising: a metallic resonance cavity having a cuboid shape defining three orthogonal axes x, y, z substantially aligned with walls of the metallic resonance cavity and having a central axis extending in the z direction; a dielectric core provided in the metallic resonance cavity, the dielectric core comprising: a central part extending coaxially with respect to the central axis of the metallic resonance cavity; and four columnar parts arranged around the central part and integrally formed with the central part and each extending in the z direction and having a petal-like shape in an x-y cross-section perpendicular to the z direction, every two adjacent columnar parts being spaced by a groove, the dielectric core being centrosymmetric and axisymmetric in each x-y cross-section perpendicular to the z direction, wherein the metallic resonance cavity has a square cross-section, and in each petal-like cross-section, each columnar part extends in a direction of an adjacent corner area of corresponding square cross-section of the metallic resonance cavity, and a height of the central part is not greater than a height of a main body of each columnar part when measured in the z direction. The present disclosure also relates to a dielectric cavity filter comprising the above-mentioned dielectric cavity resonator.