Abstract
A passive, long range, wide angle, chipless radio-frequency identification (RFID) tag operating in the S-band is presented in this paper. The proposed design consists of a broadband Van Atta retrodirective array incorporating perfectly matched bandstop filters in its feeding network, to encode identifying information across the frequency spectrum in the reflected signal while tracking the direction of the reader. As a result we are able to obtain a low-cost, high performance, microwave version of barcode that is easy to implement. A prototype is fabricated and radar cross section (RCS) is measured across the frequency range for three different combinations of identifying bits, to validate both the tracking capability and the data encoding ability of the design.