Antenna apparatus and a method of operating the antenna apparatus are provided. The antenna apparatus comprises a directional antenna comprising antenna array components, RF chains connected to the antenna array components, and a transceiver connected to the RF chains. Each RF chain comprises in sequence: a switching stage having switching circuitry selectively to connect an antenna array component, a phase shifting stage having phase shifting circuitry, and a summation stage having summation circuitry, wherein at least two of the RF chains share phase shifting circuitry and at least two of the RF chains share summation circuitry. The at least partial sharing of the RF chains, an in particular of the phase shifting circuitry provides a compact and cheap antenna apparatus, which is nonetheless capable of degree of configurability in direction and beam pattern to enable it to operate in a busy and changing environment.