An antenna for the reception of circularly polarized satellite radio signals, comprising at least one horizontally oriented conductor loop arranged above a conductive base surface and an arrangement connected to an antenna connector for the electromagnetic excitation of the conductor loop, comprising the following features: - the conductor loop is configured as a ring line radiator and forms a resonant structure and can be electrically excited by the arrangement for electromagnetic excitation such that the current distribution of a running line wave in a single rotation direction is adopted on the ring line with an extended length L, the phase difference of which line wave, over one revolution, amounts to just 2π; - the ring line radiator is configured by means of a square closed line ring having an edge length of U4 extending in a horizontal plane having a height h above the conductive base surface, characterized in that - for supporting the vertically oriented portions of the electromagnetic field, four vertical radiators, which extend toward the conductive base surface are present at the periphery of the ring line radiator at its corners, are electromagnetically coupled with the ring line radiator and are electromagnetically coupled via low-loss reactance circuits with the electrically conductive base surface; and - a ramp-shaped directional coupling conductor is provided which leads, starting from the antenna connector located at the conductive base surface via a further vertical radiator up to a coupling spacing, to one of the corners of the ring line radiator, comes together with the base surface from there in accordance with a ramp function approximately beneath an adjacent corner and is conductively connected thereto via a ground connection point to generate a continuous line wave on the ring line radiator and for a contactless coupling to the ring line radiator. - the conductor loop is configured as a ring line radiator and forms a resonant structure and can be electrically excited by the arrangement for electromagnetic excitation such that the current distribution of a running line wave in a single rotation direction is adopted on the ring line with an extended length L, the phase difference of which line wave, over one revolution, amounts to just 2π; - the ring line radiator is configured by means of a square closed line ring having an edge length of U4 extending in a horizontal plane having a height h above the conductive base surface, - for supporting the vertically oriented portions of the electromagnetic field, four vertical radiators, which extend toward the conductive base surface are present at the periphery of the ring line radiator at its corners, are electromagnetically coupled with the ring line radiator and are electromagnetically coupled via low-loss reactance circuits with the electrically conductive base surface; and - a ramp-shaped directional coupling conductor is provided which leads, starting from the antenna connector located at the conductive base surface via a further vertical radiator up to a coupling spacing, to one of the corners of the ring line radiator, comes together with the base surface from there in accordance with a ramp function approximately beneath an adjacent corner and is conductively connected thereto via a ground connection point to generate a continuous line wave on the ring line radiator and for a contactless coupling to the ring line radiator.