According to an example aspect of the present invention, there is provided an antenna array for a transmit-array antenna system with a fixed feed antenna, comprising an inner radiating surface for receiving a first signal from the fixed feed antenna, an outer radiating surface for emitting a second signal from the antenna array and a platform for electric connection of Radio Frequency, RF, components disposed between the inner and outer radiating surfaces, the platform having a phase shifter for operatively connecting the inner and outer radiating surfaces.