Method and apparatus for controlling power division in a travelling-wave antenna

This publication discloses a method and apparatus for feeding signal power to an antenna array comprising several antenna elements ( 1 - 4 ). According to the method, the signal power is fed to the antenna elements ( 1 - 4 ) over two transmission lines (a-b) and (c-d), in which case the divisions (e) of one of the transmission lines (a-b) are shorter than the nominal wavelength and those (f) of the other (c-d) are longer than the nominal wavelength by the same amount, the signal s being fed is divided into two parts, one of which is led to one of the said two transmission lines (a) and the other to the opposite end (d) of the other line, in which case the signals travel in the lines in opposite directions, and the signals are summed ( 5 ) before the antenna elements ( 1 - 5 ).