Device for reading radio frequency identifiers for volumetric confining of the detection region
Medeiros, C. R.
Fernandes, C. A.
Patent Nr.: WO2009/157791
Regional Coverage: International
Grant Status: Granted
Filling Date: 28-06-2008
Granting Date: 30-12-2009
Device for reading radio frequency identifiers (RFID) ensuring volumetric confinement at UHF of the detection of RFID tags to a desired volume above a reading surface, which includes one or more metallic transmission lines (6) printed on a dielectric substrate (8), on a metallic reference ground plane (7), an RFID reader or interrogator (3) at one end and a load (10) at the other end whereby a structure (19,21,22,23), that comprises the reading surface, in which the one or more transmission lines (6), the dielectric substrate (8) and the metallic reference ground plane (7) are embedded or attached, and the electric fields (11) are contained in planes perpendicular to the one or more transmission lines (6) with one to five wavelengths that extend over all or part of the length of the reading surface, and wherein the dialectric substrate (8) has a low permittivity, less than 1,5 and the width of the transmission line (6) is comprised between 8 and 15% of the wavelength.