Patent ID: 7839352

Claim:
A resonant tag and carrier, the tag resonating with a radio wave at a predetermined frequency, the tag comprising: a polypropylene film having a thickness of approximately 8 μm or less; a first circuit comprising a first metal foil including a coil portion and a plate portion, which comprises a first plate of a capacitor, formed on one side of said polypropylene film; a second circuit made of a second metal foil including a plate section which comprises a second plate of said capacitor, formed on the other side of said polypropylene film; a first paper layer adhered to said first circuit side; a second paper layer adhered to said second circuit side; and wherein said both circuits comprise an LC circuit by being electrically connected; the carrier comprising a fluid-permeable fabric; wherein the tag is enclosed in the carrier such that when the carrier and tag are immersed in water, said paper layers are saturated with said fluid.