Patent ID: 6281794
Filing Date: 2001-08-28
Classification: G06K,G08B,H01L,H01Q

Abstract:
A radio frequency identification transponder (RFID tag) comprising:a tag antenna having impedance Z.sub.a,radio frequency identification (RFID) circuitry responsive to electromagnetic signals received at the tag antenna, the circuitry having an input impedance Z.sub.L, andan inductor having an impedance Z.sub.ind connected in series between the antenna and the RFID circuitry, the value of the inductor chosen to maximize the expression [(R.sub.a)(G.sub.a)].sup.1/2.vertline.(Z.sub.L).vertline./.vertline.(Z. sub.a +Z.sub.ind +Z.sub.L).vertline., where .vertline. .vertline. indicates the absolute value of the enclosed expression.