Abstract: A device for the power transmission of microwaves between a strip-line and a number of parallel cavity waveguides arranged in a group antenna. The strip-line includes H-shaped slots. These slots are centered with respect to a central conductor. Opposite each of the slots, a corresponding slot is arranged through the wall of the cavity waveguide. Electrically conducting seals are arranged to follow immediately outside the contours of the slots. The strip-line is fixedly fastened to the seals and the ridge waveguide, whereby good electrical coupling is achieved. Simultaneously, small cavities are formed between the slots. These cavities have a leveling effect such that the demands on mechanical precision is appreciably lowered, such that the tolerance to placement of the slots opposite to each other is increased substantially as compared to the case of the waveguides directly abutting the strip-line.