<p>A portal antenna (10) particularly suited for enabling low frequency RFID devices carried by animals to be read when animals are proceeding through a stock race or the like. The portal antenna includes a portal structure (11) through which an animal can pass and about which is wound at least one coil (18/19) of antenna conductor. At least one elongate radiator element (21) preferably projects to at least one side of the portal structure (11). Preferably the radiator(s) (21) is/are of ferrous/magnetically conductive metal. The radiator(s) can form a separate structure or be part of the wall structure of a stock race.</p>
