Radio frequency tag with miniaturized resonant antenna

An RF transponder is provided with a miniature resonant antenna that can fit on a small form factor the size of a button or coin. More particularly, the RF transponder comprises a substrate and an RF integrated circuit disposed thereon. An antenna is provided on the substrate and is electrically connected to the RF integrated circuit. The antenna has a contorted shape that permits it to fit into the limited available space on the substrate, while having an electrical length that is greater than a maximum length dimension of the substrate. Possible shapes for the antenna may include a meander antenna, a non-uniform meander antenna, a bent dipole antenna, a spiral antenna, a z-shaped dipole, a squeezed dipole antenna, or a combination of any of the antenna types. The RF transponder may further include at least one loading bar spaced from the antenna and/or at least one tuning stub coupled to the antenna.