at least two balanced radiation elements arranged to form a planar structure and operable to transmit a corresponding number of partial signals, the balanced radiation elements also being operable to receive the corresponding number of partial signals;

a signal splitter operable to split a signal received from an attached transceiver circuitry into said partial signals, the signal splitter being configured to combine said partial signals into a signal to be transmitted to an attached transceiver circuitry;

a phase shifter device operable to apply relative phase shifts between at least two of said partial signals, said relative phase shifts being selectable from a group of at least two relative phase shift values provided by said phase shifter device,

wherein the phase shifter device includes a number of phase shifter banks according to a number of radiation elements, each phase shifter bank including a plurality of selectable delay lines, each phase shifter bank being operable to shift a phase of a corresponding one of said partial signals using a selected one of said plurality of selectable delay lines.