US Patent 7633460 Antenna for a backscatter-based RFID transponder

An antenna for a backscatter-based RFID transponder is provided with an integrated receiving circuit, having a capacitive input impedance, for receiving a radio signal lying spectrally in an operating frequency range, whereby the antenna has two antenna arms, which extend outward in a spiral from a central region in which the antenna arms can be connected to the integrated receiving circuit. According to the invention, a ring-shaped trace is provided, which extends completely around the central region and is formed to connect the antenna arms conductively to one another. The invention relates further to a backscatter-based RFID transponder with an antenna of this type.