This letter proposes a low-cost, compact, fully printable and flexible
chipless radio frequency identification (RFID) tag. The tag has a
linearly polarized geometry and is designed within a miniaturized
footprint of 20 x 10 mm². It has the capability to encode 15-bit data which means that it can label 2¹⁵
number of objects. The tag demonstrates the humidity sensing feature by
using HP photopaper as substrate along with silver nano-particle based
conductive ink as a radiator in a frequency range of 2.4-14.6 GHz. The
speciality of the tag relies in its ability to exhibit the humidity
sensing phenomenon by using flexible, economical and abundantly
available organic HP photopaper substrate; thus making it an excellent
choice for green electronic based smart sensing applications.