Radio frequency filter with a coaxial design, having the following features: - comprising an outer conductor housing having a housing base and a housing wall, - a plurality of resonators (1; 1a, 1b, 1c, 1d) are formed in the outer conductor housing, - the resonators (1; 1a, 1b, 1c, 1d) each comprise an inner conductor which is electrically coupled to the housing base and is provided in an associated resonator cavity in the outer conductor housing, which cavity is delimited by housing or side walls, - a transmission path extends through the radio frequency filter, for which purpose in each case two adjacent resonators are interconnected via at least one coupling opening, - an adjusting or shifting device (24, 25) is provided for changing the coupling bandwidth, - the adjusting or shifting device (24, 25) comprises at least one adjusting means to which at least one coupling element is attached, - the coupling element is associated with one of the at least one coupling opening located in the transmission path, - the coupling element is planar, with a plane of the coupling element extending in parallel with or at least approximately in parallel with the associated coupling opening, and - the coupling element is arranged in the resonator (1; 1a, 1b, 1c, 1d), in relation to this associated coupling opening, such that by adjusting the adjusting or shifting device (24, 25) the adjusting means and thus the coupling element can be adjusted between two extreme positions in which the coupling element is adjusted or positioned wholly or partially into the coupling opening located on the transmission path or wholly or partially out of this coupling opening or away from this coupling opening, - the adjustment of the adjusting or shifting device (24, 25) of the adjusting means and thus of the coupling element extending in a direction parallel to the plane of the coupling element, characterised by the following additional features: - the at least one coupling element is arranged without contact with the side walls and the partition walls, - the direction of adjustment of the adjusting or shifting device (24, 25) of the adjusting means and thus of the coupling element is perpendicular to the longitudinal direction of the inner conductor. - comprising an outer conductor housing having a housing base and a housing wall, - a plurality of resonators (1; 1a, 1b, 1c, 1d) are formed in the outer conductor housing, - the resonators (1; 1a, 1b, 1c, 1d) each comprise an inner conductor which is electrically coupled to the housing base and is provided in an associated resonator cavity in the outer conductor housing, which cavity is delimited by housing or side walls, - a transmission path extends through the radio frequency filter, for which purpose in each case two adjacent resonators are interconnected via at least one coupling opening, - an adjusting or shifting device (24, 25) is provided for changing the coupling bandwidth, - the adjusting or shifting device (24, 25) comprises at least one adjusting means to which at least one coupling element is attached, - the coupling element is associated with one of the at least one coupling opening located in the transmission path, - the coupling element is planar, with a plane of the coupling element extending in parallel with or at least approximately in parallel with the associated coupling opening, and - the coupling element is arranged in the resonator (1; 1a, 1b, 1c, 1d), in relation to this associated coupling opening, such that by adjusting the adjusting or shifting device (24, 25) the adjusting means and thus the coupling element can be adjusted between two extreme positions in which the coupling element is adjusted or positioned wholly or partially into the coupling opening located on the transmission path or wholly or partially out of this coupling opening or away from this coupling opening, - the adjustment of the adjusting or shifting device (24, 25) of the adjusting means and thus of the coupling element extending in a direction parallel to the plane of the coupling element, - the at least one coupling element is arranged without contact with the side walls and the partition walls, - the direction of adjustment of the adjusting or shifting device (24, 25) of the adjusting means and thus of the coupling element is perpendicular to the longitudinal direction of the inner conductor.