One or more adjustable resonators (208, 209) of a compensation circuit are arranged so that adjusting the resonators nevertheless results in output of the circuit remaining substantially constant. This has been accomplished by separating resonator cavities that include the adjustable resonators by a partition wall. A coupling aperture (205) provides inductive coupling between the resonator cavities and a capacitive part (206) passes through the intermediate wall and provides a capacitive coupling between the resonator cavities. The capacitive part is conductive and electrically isolated from the partition wall. The capacitive part and the coupling aperture are dimensioned such that effects on the coupling band width of the aperture and capacitive couplings track each other so as to substantially cancel each other out, and that the coupling band width between the resonator cavities remains substantially constant.

A coaxial filter having a frame construction comprises at least one filter frame, which consists of an electrically conductive medium and comprises a receiving space. A cover arrangement closes the receiving space on all sides. At least one first resonator internal conductor is arranged in the receiving space. The at least one first resonator internal conductor is galvanically connected to a face of the at least one electrically conductive filter frame, and extends therefrom in the direction of another, in particular opposing face of the electrically conductive filter frame, and ends at a distance from the opposing face of the electrically conductive filter frame and/or is galvanically separated from the opposing face of the electrically conductive filter frame.

The present invention relates to a dielectric waveguide filter, comprising a dielectric substrate, wherein the dielectric substrate comprises a plurality of resonators; the plurality of resonators are connected to each other; the dielectric substrate further comprises a negative coupling blind hole; the negative coupling blind hole is arranged at a joint between two adjacent resonators; the two adjacent resonators are respectively provided with a tuning blind hole; and the tuning blind hole of one of the two adjacent resonators is connected to the negative coupling blind hole by a first coupling structure. The present invention can effectively suppress parasitic coupling of the dielectric waveguide filter.

A dielectric resonator includes a dielectric substrate, a distributed element, and a shield conductor portion. The distributed element extends in the X-axis direction inside the dielectric substrate. The shield conductor portion is on a surface of the dielectric substrate and winds around the distributed element when the distributed element is viewed from the X-axis direction in plan view. One end of the distributed element is not connected to the shield conductor portion. The distributed element includes a plurality of conductors.

The present disclosure provides a cavity filter assembly installed with an RF filter having an empty area formed between the RF filter and a cavity filter body serving as a ground to reduce the parasitic capacitance by forming the cavity filter body with a first pocket portion configured to install the RF filter and a second pocket portion within the first pocket portion in a position to overlap a transmission line, thereby reducing the insertion loss of the RF filter, which when serving as a low-pass filter, can position the harmonics in the stopband further away from the cutoff frequency and thus effect improved frequency characteristics of the low-pass filter through improvements of, for example, the frequency characteristics in the stopband.

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.

A frequency variable filter includes variable resonators aligned in a predetermined direction, a coupling part configured to couple the adjacent variable resonators, and a coupling variable dielectric. The variable resonator includes a resonator and a frequency variable dielectric disposed in a movable state relative to the resonator, and is configured to be able to change a resonance frequency according to a position of the frequency variable dielectric with respect to the resonator. This applies to aligned variable resonators other than this variable resonator. The coupling variable dielectric is disposed in a movable state with respect to the coupling part and configured to adjust a coupling coefficient according to an amount of insertion into the coupling part. The coupling variable dielectric is disposed so that a movable surface of the coupling variable dielectric is on the same plane as a movable surface of the frequency variable dielectric.

Disclosed are embodiments of ceramic radiofrequency filters advantageous as RF components. The ceramic filters can include a ceramic stepped impedance resonator, wherein the inner diameter of the ceramic stepped impedance resonator can vary from one end to another end. The inner diameter can be, for example, tapered, sectioned, or stair-stepped in order to provide different impedances in the ceramic resonator.

Example embodiments of the present disclosure provide a resonator (100) and a filter (500). The resonator (100) comprises a capacitance metal sheet (110), an inductance metal sheet (120) and a mounting metal sheet (130). The capacitance metal sheet (110) is configured to generate capacitance of the resonator (100) with a top surface (202) of a metal cavity (200) for housing the resonator (100). The inductance metal sheet (120) is configured to generate inductance of the resonator (100), which is connected to the capacitance metal sheet (110) and extends to a bottom surface (204) of the metal cavity (200). The mounting metal sheet (130) is connected to the inductance metal sheet (120) and configured to mount the resonator (100) in the metal cavity (200). The example embodiments of the present disclosure can implement a resonator and a filter with high performance, small size and low cost.

A cross-coupled filter includes a minimum resonant structure including four resonators. In the minimum resonant structure, two resonators in the same row form a group, and two resonators in the same row are capacitively mainly coupled or inductively mainly coupled; two resonators in the same column are electrically and magnetically hybrid coupled; and the coupling polarities of the two groups of resonators in the two rows of resonant units are opposite to each other and form at least a cross-coupling. The invention realizes miniaturization and light weight in structural characteristics, and realizes low loss and good harmonic characteristics in electrical performance.