A coaxial filter comprises a housing that surrounds a receiving space. The housing comprises a trough-shaped housing element with sidewalls and a front wall. The housing further comprises a further trough-shaped housing element, wherein the two trough-shaped housing elements are placed on top of one another, thus forming the receiving space; or a lid arrangement which, together with the trough-shaped housing element forms the receiving space. At least one resonator inner conductor arrangement comprises a connecting bridge, with which resonator inner conductors are conductingly connected.

A coaxial filter comprises a housing that surrounds a receiving space. The housing comprises a trough-shaped housing element with sidewalls and a front wall. The housing further comprises a further trough-shaped housing element, wherein the two trough-shaped housing elements are placed on top of one another, thus forming the receiving space; or a lid arrangement which, together with the trough-shaped housing element forms the receiving space. At least one resonator inner conductor arrangement comprises a connecting bridge, with which resonator inner conductors are conductingly connected.

Difficulties in grounding a non-integral, deep drawn resonator (DDR) to the filter body of a cavity may be substantially eliminated by preventing the movement of the DDR away from a grounding contact area on the filter body. The addition of a compression plate and stop limiter in the connection of the non-integral DR to the filter body helps insure that any such movement is eliminated or substantially reduced.

Difficulties in grounding a non-integral, deep drawn resonator (DDR) to the filter body of a cavity may be substantially eliminated by preventing the movement of the DDR away from a grounding contact area on the filter body. The addition of a compression plate and stop limiter in the connection of the non-integral DR to the filter body helps insure that any such movement is eliminated or substantially reduced.

A rod-switched tunable resonator includes a housing defining a cavity, a first rod disposed within the cavity, a second rod disposed within the cavity, and a switch connected to the first rod and to the second rod to tune the resonator to one of a plurality of frequencies by connecting or disconnecting one or both of the first and second rods to the housing. A tunable filter may be fabricated using two or more such resonators. The rod-switched tunable resonator may be a combline resonator, coaxial resonator, waveguide resonator, or dielectric resonator.

An exemplary cavity resonator has a resonant frequency and includes a conductive body containing a cavity and a plate attached to the body enclosing the cavity. The position of a conductive tuning mechanism that protrudes into the cavity affects the tuning of the resonant frequency of the cavity resonator. A portion of the enclosed cavity is made of a shape memory alloy (SMA) material that has been trained to have a coefficient of thermal expansion that results in dimensional changes of the portion as the temperature varies so that the dimensional changes produce changes in the resonant frequency that counteract the combined change in the resonant frequency due to dimensional changes with temperature associated with the other portions of the enclosed cavity made of materials other than SMA material. This results in a stable resonant frequency versus temperature characteristic.

A stripline manifold filter assembly for an antenna includes a stripline manifold bandpass filter. The stripline manifold bandpass filter includes coupled lengths of transmission lines that form coaxial resonators and couplings. The stripline manifold bandpass filter includes coupling bars attached to adjacent coaxial resonators as well as inductive bars attached to coaxial resonators to provide the necessary coupling and resonant frequency requirements to achieve the desired filter response.

A stripline manifold filter assembly for an antenna includes a stripline manifold bandpass filter. The stripline manifold bandpass filter includes coupled lengths of transmission lines that form coaxial resonators and couplings. The stripline manifold bandpass filter includes coupling bars attached to adjacent coaxial resonators as well as inductive bars attached to coaxial resonators to provide the necessary coupling and resonant frequency requirements to achieve the desired filter response.

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.

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.