Comparison of UWB chipless tags on flexible substrates fabricated using either aluminum, copper or silver

In this paper, metals like aluminum, copper and silver are used to elaborate ultra-wide band (UWB) chipless radio frequency identification (RFID) tags either on bond paper or polyethylene terephthalate (PET) substrates. Up to 3 different UWB chipless tags designs with an amount of resonators ranging from 3 to 4 and a conductive strip width of 1 mm are fabricated. The tags are measured, its operation validated, and the performance comparisons between different fabrications are provided when available. The magnitudes of the radar cross section (RCS) calculated from the measurements of the scattering parameters, show that no major performance degradation is obtained for same tag designs fabricated with different metals and same substrate. According to market prices, replacing silver by copper a raw material cost reduction of at least 96% is expected, and at least 65% cost reduction replacing copper by aluminum.