Mm-wave chipless RFID tag for low-cost item tagging

A 6-bit mm-wave chipless RFID tag comprises 2 orthogonally polarized slot loaded circular patch antennas, which are connected by a right angle transmission line. The slot on the patch determines individual resonant frequency signatures hence the number of identification data bits. To accommodate large number of data bits and provide isolation between the resonant signatures, the patches are polarized orthogonally so that adjacent signatures do not overlap each other. The tag is fully printable. Being a mm-wave ultra-wide band (UWB) tag, the tag can easily be printed on access and business cards, bus tickets and postage stamps. It has huge potential for low-cost item tagging and authentication.