Abstract: The Method for transmitting a signal from a transmitter in an area around the transmitter via a satellite comprising the steps of transmitting a first signal having a first frequency from the transmitter to a satellite having a retrodirective antenna array comprising receiving antennas and transmitting antennas, receiving the signal transmitted from the transmitter by the receiving antennas of the retrodirective antenna array as first signals wherein the first signals received by the receiving antennas have a phase relation among each other defined by the geometric arrangement of the receiving antennas, and retrodirectively re-transmitting second signals from the transmitting antennas of the antenna array of the satellite in the direction towards the transmitter in the form of a beam with the transmitter located substantially in the center of the beam wherein the second signal has a second frequency different from the first frequency and wherein the phase relations among the second signal transmitted from

Abstract: A reflector antenna, in particular for the reception and/or transmission of signals from and/or to satellites. The reflector antenna according to the invention comprises a reflector arrangement for focusing antenna radiation in a focal plane together with an antenna array arranged in the focal plane, or in the vicinity of the focal plane, with a plurality of antenna elements. A control device is provided with a beamforming means. Through the control device, sub-arrays, comprising one or a plurality of antenna elements of the antenna array for the reception and/or transmission of antenna radiation, can be activated and deactivated. In the operation of the reflector antenna, a radiation lobe pattern is formed by means of the beamforming means for the reception and/or transmission of antenna radiation for a particular activated sub-array.

Abstract: The Method for transmitting a signal from a transmitter in an area around the transmitter via a satellite comprising the steps of transmitting a first signal having a first frequency from the transmitter to a satellite having a retrodirective antenna array comprising receiving antennas and transmitting antennas, receiving the signal transmitted from the transmitter by the receiving antennas of the retrodirective antenna array as first signals wherein the first signals received by the receiving antennas have a phase relation among each other defined by the geometric arrangement of the receiving antennas, and retrodirectively re-transmitting second signals from the transmitting antennas of the antenna array of the satellite in the direction towards the transmitter in the form of a beam with the transmitter located substantially in the center of the beam wherein the second signal has a second frequency different from the first frequency and wherein the phase relations among the second signal transmitted from