Abstract: In a method and a device for reduction of intermodulation distortion in radio communication systems, a signal, which is intended to be transmitted, is fed to an active antenna for transmission in a main lobe. The antenna includes a plurality of transmitter stages each of which is supplied with a partial signal and includes an input stage, an amplifier, an output stage and an antenna element. A first phase rotation of each partial signal is performed before each amplifier, and a second phase rotation of each partial signal is performed after each amplifier. The sum of the first phase rotation and the second phase rotation is chosen to a value which is constant, and the second phase rotation is chosen so that an intermodulation lobe which is transmitted from the antenna is controlled in a direction which deviates substantially from the direction of said main lobe.

Abstract: The present invention relates to an arrangement at transmission of a number of signals each having a frequency component, between a base station unit and an antenna arrangement having a number of radiation element. The base station unit includes a combiner unit in which signals containing a frequency component are combined to a multi-frequency signal which is transmitted to the antenna arrangement (20). This includes a power dividing unit (3) in which the multi-frequency signal is divided into a number of, preferably similar multi-frequency subsignals and a number of controllable filter arrangements (4.sub.1, . . . , 4.sub.n) for extracting a number of signals essentially consisting of a frequency from multi-frequency subsignals. Moreover, the antenna arrangement includes a number of amplification devices (5.sub.1, . . , 5.sub.n), in which single-frequency signals are amplified for feeding to a number of radiation elements (6.sub.1, . . . , 6.sub.n).