Abstract: An active radio frequency identification (REID) tag implemented on a flat label. The tag includes a battery printed on the label, a flat wide-band antenna printed on the label and a wide band communication circuit implemented as a chip inlay inside the label. The circuit is attached to the battery and to the antenna. The combined thickness of the battery, the antenna and the circuit as printed on the flexible label is less than one millimeter. The battery, the antenna and the circuit are printed on the label so as to render substantial flexibility to the RFID tag. The circuit operates at a center frequency of at least one gigahertz and a bandwidth at least twenty percent of said center frequency or a bandwidth at least 500 Mhz. The tag typically includes an inaccurate clock source such as an RC circuit and does not include a crystal.