A dipole part of a length shorter than half of an antenna resonance
wavelength is placed so as to be rolled and enables a feeding part 11 to
feed a chip. An inductance part 12 for adjusting the inductance of the
antenna is provided so as to sandwich the feeding part 11. The inductance
12 is provided using an empty space of the inside of the rolled dipole
part. By providing the inductance part 12, the inductance of the antenna
can be adjusted so as to resonate at a predetermined frequency with the
capacitance of the chip connected to the feeding part 11. At this time,
although the radiation resistance of the antenna becomes extremely large
according to calculations, it is actually almost the same as the
resistance of the chip due to loss, and the power received by the antenna
can be provided to the chip.