A balun arrangement (1, 1', 1") comprising: - a single-ended port (2, 2'; 17, 26); - a differential port arrangement comprising a first differential port and a second differential port; - a first transmission line section and a second transmission line section which are electromagnetically mutually coupled such that a first coupled pair is obtained; and - a third transmission line section and a fourth transmission line section which are electromagnetically mutually coupled such that a second coupled pair is obtained; where - the first transmission line section is connected between a first coupled pair first port and the third transmission line section; - the second transmission line section is connected between a first coupled pair second port and the first differential port; - the third transmission line section is connected between a second coupled pair first port and the first transmission line section; and - the fourth transmission line section is connected between a second coupled pair second port and the second differential port; wherein the balun arrangement (1") further comprises a first switching arrangement, a second switching arrangement, a third switching arrangement and a fourth switching arrangement; where, for the first coupled pair: - the first coupled pair first port is connected to a first switch port of the balun arrangement and the first switching arrangement that is arranged to switch the first coupled pair first port and the first switch port to open circuit, in a first switch state, and to ground, in a second switch state; and - the first coupled pair second port is connected to the second switching arrangement that is arranged to switch the first coupled pair second port to ground, in the first switch state, and to open circuit, in the second switch state; and for the second coupled pair: - the second coupled pair first port is connected to a second switch port of the balun arrangement and the third switching arrangement that is arranged to switch the second coupled pair first port and the second switch port to ground, in the first switch state, and to open circuit, in the second switch state; and - the second coupled pair second port is connected to the fourth switching arrangement that is arranged to switch the second coupled pair second port to open circuit, in the first switch state, and to ground, in the second switch state, such that, in the first switch state, the first switch port constitutes the single-ended port, and, in the second switch state, the second switch port constitutes the single-ended port. - a single-ended port (2, 2'; 17, 26); - a differential port arrangement comprising a first differential port and a second differential port; - a first transmission line section and a second transmission line section which are electromagnetically mutually coupled such that a first coupled pair is obtained; and - a third transmission line section and a fourth transmission line section which are electromagnetically mutually coupled such that a second coupled pair is obtained; - the first transmission line section is connected between a first coupled pair first port and the third transmission line section; - the second transmission line section is connected between a first coupled pair second port and the first differential port; - the third transmission line section is connected between a second coupled pair first port and the first transmission line section; and - the fourth transmission line section is connected between a second coupled pair second port and the second differential port; - the first coupled pair first port is connected to a first switch port of the balun arrangement and the first switching arrangement that is arranged to switch the first coupled pair first port and the first switch port to open circuit, in a first switch state, and to ground, in a second switch state; and - the first coupled pair second port is connected to the second switching arrangement that is arranged to switch the first coupled pair second port to ground, in the first switch state, and to open circuit, in the second switch state; - the second coupled pair first port is connected to a second switch port of the balun arrangement and the third switching arrangement that is arranged to switch the second coupled pair first port and the second switch port to ground, in the first switch state, and to open circuit, in the second switch state; and - the second coupled pair second port is connected to the fourth switching arrangement that is arranged to switch the second coupled pair second port to open circuit, in the first switch state, and to ground, in the second switch state,