RFID tags are provided with a substrate including opposing first and second surfaces each having first and second portions defined by a fold line therebetween. A conductive trace defines a first coil associated with the first portion of the first surface and a second coil associated with the second portion of the first surface. The first coil has a first number of turns, while the second coil has a second number of turns. An RFID chip is electrically coupled to the conductive trace. The substrate is folded at the fold line so as to bring the first and second portions of the first surface into facing relationship, with at least a portion of the first coil overlapping at least a portion of the second coil. The overlapping coils define an antenna having a number of turns equal to the sum of the number of turns of the two coils.