US Patent 7595753 Broadband beam steering antenna

An antenna apparatus attachable to the front-end of a transceiver circuitry, includes at least two balanced radiation elements forming a planar structure for transmitting and/or receiving a corresponding number of partial signals. The antenna apparatus also includes a signal splitter and/or combiner for splitting a signal received from an attached transceiver circuitry into said partial signals and/or combining said partial signals into a signal to be transmitted to an attached transceiver circuitry, a phase shifter device that applies relative phase shifts between at least two of said partial signals. The relative phase shifts are selectable from a group of at least two relative phase shift values provided by the phase shifter device.