Antenna device.

摘要

The data pick-up unit is in the form of a landing stage (1) with the inductive reading devices divided into a number of fields. An antenna operable with frequencies in the MHz range are formed on circuit boards formed on rollers (2). The rollers are freely supported on bearings. Pigeons landing on the bed move into the loft and in doing so the rings on the leg are read. By dividing the landing stage into sections, individual pigeons are identified without ambiguity.